# Pm-940m-cnc (pre-assembled)



## fugawii

Hi.  I am a new forum member.  Great forum.  Great members.  Great advice.  I'd like to start a thread for PM-940M CNC owners.  There's not a lot of model specific help out there for this machine.  Is there anyone else out there that has one of these and could share some Mach 3 settings?  The set up manual that comes with it is translated and hard to decipher.  Here are some links and files that have helped me so far.  I'm not 100% operational yet.  I'm finding a lot of conflicting pins/port numbers between the various model numbers.


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## fugawii

http://www.hobby-machinist.com/threads/pm-45m-cnc-setup-and-configuration-with-mach3.21179/


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## TomS

There are a several of us that have bought/converted PM-45's, PM-932's and a few PM-940's so there's a large base of knowledge that you can tap into to make your build go easier.  Most are running Mach 3 with a few running other control software.  

I have a PM-932 that I converted about 1-1/2 years ago.  I'd be more than happy to share my setup files and screen shots.  Let me know what you need help with and I'll post them.

Tom S.


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## fugawii

Thanks TomS.  I appreciate it.  I have about a week of wheat harvest left.  Once that is out of the way I will me able to dedicate more than a few minutes each morning to the mill.  I have everything functioning except the spindle.  I'm getting closer!


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## JimFouch

I also have a PM-940M-CNC I got at the end of last year. I managed to break it down into small enough pieces to have about 5-6 friends help me move it into my basement. I'm still working on getting it all set up the way I want it. I did have to reduce the limits on the travel of the Z-axis due to my ceiling height. I lost about 1" of travel. But, to have it located inside where I can use it year round is worth it.


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## fugawii

Arrrgh.  I still can't get this spindle to turn. FWD & REW lights up on the VFD in the cabinet when i toggle spindle.  Could someone share some screenshots of their Mach3 settings for the PM-940M-CNC?  I am using Windows 7, Mach3, VFD, USB connection to the Jamen controller card.  I've emailed Precision Matthews and they sent me the .pdf's in my first post(sigh).  Do i need to do any setup on the VFD?  While i appreciate the self-education on Mach 3 and JNC-40M, it seems to me they would have much happier customers if they included a Mach3 setup file on the CD they ship it with.  At the very least some customer support would be appreciated.  Deciphering and decoding the JNC-40M controller manual is kicking my butt.


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## profmason

fugawii said:


> Arrrgh.  I still can't get this spindle to turn. FWD & REW lights up on the VFD in the cabinet when i toggle spindle.  Could someone share some screenshots of their Mach3 settings for the PM-940M-CNC?  I am using Windows 7, Mach3, VFD, USB connection to the Jamen controller card.  I've emailed Precision Matthews and they sent me the .pdf's in my first post(sigh).  Do i need to do any setup on the VFD?
> 
> 
> 
> YES. I have a pm940 cnc.  Need to setup vfd according to manual.  Test it in manual mode first.  Set mode to F 1.2.  (At least on my model)  I futzed with the cds for an hour during setup.   Good luck


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## fugawii

I sent an email to Precision Matthews asking about the VFD. I just received a reply from Greg at Precision Matthews.  Matt is on vacation for the next week and is still unavailable.  He claims no setup to the VFD is required.


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## RogerC

Just ran across this thread.  I also have a PM-940M-CNC.  I have removed the stock controller and replaced it with an ESS controller which has made setup easier.  I am also able to do backlash compensation in Mach3 with the ESS, whereas I was unable to get it to do anything with the JNC controller.  If anyone has questions I will try and help.


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## cut2cut

I should be getting a new PM-940-CNC-VS from Precision Mathews / Quality Machine Tools in the coming weeks.     I will contribute my experience here so others can benefit as much as I have from the posts already made.     ( Huge thanks to the guys that posted their Mach3 setup tutorials for the closely related  PM-45M-CNC mentioned above.  )

I'm somewhat experienced with Mach3 and have converted a smaller mill to CNC.    At some point I expect to move to a Mesa Controller and use LinuxCNC via Ethernet.   Also after ensuring everything works I will likely remove the electronics box from the rear of the column so I can build an enclosure for chip and coolant containment.  I will share my experience here.

One initial question regarding the need for a ? 28mm ? spline wrench for tightening and loosening the drawbar.      I have looked online and could not find one available to purchase.  Is there a source for this that others have found ?

Happy New Year !

Jake D.


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## jbolt

You PM-940-CNC owners be sure to post lots of pictures of you machines. We like pictures. Get under the hood too. Some of us are curious how these are put together.


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## davidpbest

What is a PM-940-CNC?  There is absolutely nothing about it at the QMT web site.


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## cut2cut

davidpbest said:


> What is a PM-940-CNC?  There is absolutely nothing about it at the QMT web site.



I had inquired Precision Mathews/Quatlity Machine Tools about the PM-45CNC and he sent pictures of the PM-940 CNC which got me to inquire further.  Thats the way I happened upon it.   I suppose the 940 is a low volume seller due to it weighing more and being a larger footprint and therefore isn't as important to advertise ?     By the way, Matt has been stellar answering pre sales questions, which helped me greatly to decide which model fit my needs.

Cheers,

Jake


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## cut2cut

I think I can post links now... here is the link to the manual version of the PM-940M here on the forum:

http://www.hobby-machinist.com/threads/i-ordered-a-pm-940m-pdf.29807/

and direct to the Precision Mathews / Quality Machine tools website :

http://www.machinetoolonline.com/PM-940M.html


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## RogerC




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## davidpbest

Nice photo.   Thanks.  Exactly what is "CNC" about it - compared to the non-CNC version?  Where are the specs?


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## cut2cut

This is what Matt sent me as far as specs of the PM940-CNC and PM940-CNC-VS

Cheers,

Jake


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## davidpbest

Thank you.   Lots of people research and make decisions on machine purchases without ever talking to Matt.   For the life of me, I don't understand why he doesn't have his complete catalog on the web.   At least two users who contacted me about a benchtop CNC mill decided to buy a Tormach because "PM doesn't sell a CNC version of the PM940" - if it isn't on the web site, it doesn't exist in their mind - or my mind either.


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## phazertwo

I'm pretty much set on a PM-940 CNC at this point, and I also stumbled upon it the same, he sent me the info after I inquired about the PM-45M CNC.  You would think they would update the website.  A benchtop CNC mill that has the travel of the 940 is hard to pass up for the price.  I was leaning Tormach before I found out about the 940, which means I can get a mill with more travel sooner.

Anyway, I just need to figure out when I can actually receive the mill.  I got the same quote that said he had a few in stock on Jan 5, I would like to get my name on one of them, hopefully I can figure out when/where to pick it up.

PZ


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## jbolt

davidpbest said:


> Thank you.   Lots of people research and make decisions on machine purchases without ever talking to Matt.   For the life of me, I don't understand why he doesn't have his complete catalog on the web.   At least two users who contacted me about a benchtop CNC mill decided to buy a Tormach because "PM doesn't sell a CNC version of the PM940" - if it isn't on the web site, it doesn't exist in their mind - or my mind either.



Matt has said they will be launching a new website sometime in the near future. I'm guessing the current site is getting minimal maintenance while they work on the new one.


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## cut2cut

I found a 28mm spline wrench at "little machine shop",  I think it's the right size for the Pm940's drawbar but not 100% sure ....

Jake


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## qualitymachinetools

This web site is the hardest thing I've ever done in my life, but it seems to be getting there, never realized how much work it would be! There are 7 of us working on it, and still takes so long. Just taking the pictures of each machine have been going on for a year, not even thinking about getting it to work.   And of course, nothing could do it how I wanted, so had to have things changed around, I am certainly not a programmer, had to have that done by others.


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## fugawii

cut2cut said:


> I ordered and should receive a new PM-940-CNC-VS from Precision Mathews / Quality Machine Tools in the coming weeks.     I will contribute my experience here so others can benefit as much as I have from the posts already made.     ( Huge thanks to the guys that posted their Mach3 setup tutorials for the closely related  PM-45M-CNC mentioned above.  )
> 
> I'm somewhat experienced with Mach3 and have converted a smaller mill to CNC.    At some point I expect to move to a Mesa Controller and use LinuxCNC via Ethernet.   Also after ensuring everything works I will likely remove the electronics box from the rear of the column so I can build an enclosure for chip and coolant containment.  I will share my experience here.
> 
> One initial question regarding the need for a ? 28mm ? spline wrench for tightening and loosening the drawbar.      I have looked online and could not find one available to purchase.  Is there a source for this that others have found ?
> 
> Happy New Year !
> 
> Jake D.







I made my own drawbar wrench (very first part i cut) from this link.  http://www.cnczone.com/forums/bench...-rf-45-industrial-hobbies-spanner-wrench.html
It works great and i used it for a month before buidling my own flip down style spindle lock.  It sure eliminates the need for a third hand when using keyless chucks or endmills in collets.
  Here's a few pics.


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## fugawii

RogerC said:


> Just ran across this thread.  I also have a PM-940M-CNC.  I have removed the stock controller and replaced it with an ESS controller which has made setup easier.  I am also able to do backlash compensation in Mach3 with the ESS, whereas I was unable to get it to do anything with the JNC controller.  If anyone has questions I will try and help.



I have no love for the Jamen interface card.  I am a noob at all this, but the controller sure made the learning and setup process extra difficult.  The manual it comes with is not the greatest.  There must be a lost in the translation to English.  I've emailed the board's manufacturer a few times.  No response.  Here's a pic of the JNC-40M


Which Smoothstepper did you go with?  Are you using a breakout board?  I'm kicking around the idea of swapping it out for this combo.  http://www.cncroom.com/interface-board-mach3-mach4/smooth-stepper-ess-mb2-bob


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## jbolt

I have the PMDX-126 BoB, PMDX-107 spindle control & ESS combo on my PM-932 CNC conversion. I am extremely pleased with this setup. PMDX support is top tier.


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## DvCnewt

I also bought a Pm-940m-cnc a little over a year ago.  I was finally able to get most settings figured out.  Just gave up on the pendant controls though.
The last problem I have yet to figure out is the actual e-stop button on machine doesn't work as should.  I believe it might be the input on the Jamen board is bad.
I gave up on messing with the mill for several months now.  Time to get back to it.


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## phazertwo

fugawii said:


> I made my own drawbar wrench from this link.  http://www.cnczone.com/forums/bench...-rf-45-industrial-hobbies-spanner-wrench.html
> It works great and i used it for a month before buidling a flip down style spindle lock.  Here's a few pics.
> 
> 
> 
> 
> 
> 
> 
> 
> 
> View attachment 143549
> View attachment 143550
> View attachment 143551



Anymore info on this flip down setup.  Looks interesting.

PZ


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## fugawii

DvCnewt said:


> I also bought a Pm-940m-cnc a little over a year ago.  I was finally able to get most settings figured out.  Just gave up on the pendant controls though.
> The last problem I have yet to figure out is the actual e-stop button on machine doesn't work as should.  I believe it might be the input on the Jamen board is bad.
> I gave up on messing with the mill for several months now.  Time to get back to it.



I didn't care for the pendant at all.  Setup was too frustrating using the translated Jamen manual.  I emailed Precision Matthews about it 6 months ago.  Said they'd send me a USB one.  That was 6 months ago...  I bought a wireless hand held USB pendant mpg on Amazon.  Works great.  Easy set up.  The instruction manual was decent for an import.  An installer and a couple files to drop into the Mach3 folder and it was up and running.  Link to wireless mpg.  https://www.amazon.com/SHINA-Wirele...coding=UTF8&psc=1&refRID=PJ2SDC4G5H69QC6KT57P

Pic of wireless mpg top and stock mpg below it. 



On my machine the e-stop is orange wire (087) to pin (I11) on the JNC board.  Port 1, Pin 11, active low.  That's all I had to do on this one.  It saw a lot of use the first month. LOL


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## DvCnewt

I like the look of the wireless mpg.  Might have to look into getting one of those.  
My machine has a red wire labeled 087 to pin I11 on board.  The other end of wire is connected on the bottom of terminal strip along with another larger gauge wire also red and labeled 087.  There is no wire connected to top of terminal above it.
I did find an orange wire but not connected to anything.  
My setting in Mach3 is same.  Port 1, pin 11, active low.  E-stop on machine not working.


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## cut2cut

DvCnewt said:


> I like the look of the wireless mpg.  Might have to look into getting one of those.
> My machine has a red wire labeled 087 to pin I11 on board.  The other end of wire is connected on the bottom of terminal strip along with another larger gauge wire also red and labeled 087.  There is no wire connected to top of terminal above it.
> I did find an orange wire but not connected to anything.
> My setting in Mach3 is same.  Port 1, pin 11, active low.  E-stop on machine not working.



(Edit)  It sounds like the orange wire is the culprit. You could verify this by opening the box that  houses the E-stop button itself to see if that orange wire is connected to the E -stop.   If all else fails try wiring the E stop directly to the Jamen controller card, to test it.


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## cut2cut

Hi Guys,

I received my mill from Precision Mathews and one thing of note is the controller card has been changed to a different brand.  I assume the pendant is also different and will share a picture of it later but for now here is the supplied from factory nMotion CNC controller.







Cheers,

Jake


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## phazertwo

Em... This is exciting news.  I will be VERY interested to see how it works, and if mine comes with one.  Mine is supposed to ship tomorrow!

PZ


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## cut2cut

Ok, sorry for the delay.  Here are the pendant pictures I promised. 

I'm still getting the software configured little by little.  A fellow pm-940CNC owner has helped me test the spindle, and also showed me some wiring for things like the coolant pump that were not designated anywhere. 

X Y and Z function so far, so the new controller appears to be functioning.

So far I love the rigidity and smooth ground ways.  I have yet to check for backlash and such, but the fit feels good so far.   I do have a knocking sound in the Z that I need to inspect.  I believe it has to do with the slop in the hand crank gear interface with the ball screw...or possibly the screws holding the ball nut are not tight.  If it is the hand crank slop I'll probably remove the hand crank assembly entirely, unless it serves to keep the head from creeping down on its own weight ?

Cheers,

Jake


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## cut2cut

For those with the latest revision of the PM-940 CNC-VS (2017) that comes standard with the nMotion controller I found the default home and limit switch pins are set "backwards" in Mach 3. 
The enclosed picture is of my revised settings that now allow me to home the mill.

Cheers,

Jake


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## cut2cut

I wanted the mill to zero out with the table in the  NORTH EAST corner so I moved the home backstops to the left side of the X axis,  the rear of the Y ( near the column ) and the Z is near the top.  ( early 2017 version of the mill with nMotion controller card standard )

I changed the homing setup to what is pictured.  Note:  Please ignore the soft limits , as they are incomplete and also it depends on where you put the homing backstops on the adjustable sliding brackets.

I like this configuration because it is familiar to a standard X Y graph.  Zero is the origin, so as you go from bottom to top or left to right the movement is in the "positive" direction.  The relationship between the spindle / cutter to the table is what we are referencing.  So when the table moves from the north east to the south west, in effect the spindle is "moving" ( in relation to the table ) in the positive direction.  The spindle/cutter being the "plot" point on the graph.

Also a word of caution:   My home switch on the Y axis did not push the home button far enough to activate it.  Since the Limit switches are de-activated during homing, this could end,  "poorly".  Best to ensure that the switches are all moving far enough before you home for the first time!

I also changed the cursor keys so when I depress the left arrow key on the keyboard  the table moves left.  ..... Right arrow, the table moves right, and up arrow table moves closer to the column, and down arrow closer to me / front of the mill.    I do this because for me it is far more intuitive and so I'm less likely to crash the table and its payload into something

Cheers,

Jake


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## phazertwo

Gunrunner you need to order a set of these for the Z axis hand crank. Bill did you just spit coffee on your monitor? :rofl:

View attachment 253356


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## cut2cut

Hey PhazerTwo,

We are lucky !   Yours looks so shiny too....mine is only a a week older than yours and its all dinged up from tearing it completely apart to get it into the basement.   Thankfully just about EVERY screw was hand tight, so it was easy to tear down ;-)  

Yeah, the ways, dovetails, etc are really impressive.   The table glides around so well, and Y travel still makes me smile 

Now that its back together and I tightened the ball screw end nuts to preload the AC bearings for the X and Y.   I checked backlash and it appears to be below .001 on each axis.   I need to use a higher quality gauge to be more accurate.  The Z was a bit more complicated for me ( see below ) but after all is said and done, the Z is also about .001 backlash.

btw, I found the source of the clunking noise in the Z axis.    The solution was to remove the complete hand crank assembly which was not a very easy task but still worth it, imho.     There are two nuts on the bottom ("whip") end of the Z axis ball screw that need to be removed to remove the hand crank assembly. ( then you have to lift the ball screw high enough to remove the cast iron carriage that houses the hand crank and captures the ball screw end. ) In my opinion it shouldn't be captured as it is from the factory so I left the nuts off after reassembly.   I imagine over time, if the nuts were tight it would wear the main ball screw nut out prematurely and maybe even not allow one to preload the AC bearings on the top.  Maybe I'm over thinking it, but thats my take on it.

Jake


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## cut2cut

Forgot to mention one thing to watch out for. At least on mine ,  The steel  white cover for the X axis  stepper motor dragged onto the left side of the way when it over travels !!! Luckily I noticed it right away when i was homing the first time.  It needs to over travel to get to the limit and homing stops.   For me it was only paint that rubbed off but tolerances being off one way or the other could have resulted in damage to the X way or worse if it halted the movement of the axis.  Not sure how to fix it other than weld the holes on that side and redrill a bit lower to ensure it can't be too low.


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## phazertwo

I'll have to check this out on mine.  That would be a bummer to smash it up before it ever even makes a part!

PZ


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## Davd Flowers

One of you PM 940 cnc owners needs to put up a video so we can see what they can do


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## rodjava

I take it that the 940 cnc cant be mounted to a back wall. How much room is need to service
it from the back electric panel?


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## rodjava

I'm placing my order the the PM-940 cnc tomorrow.  My original plan was to place it up against a wall.  Then I realized that the service electronic cabinet is in the back. I contacted Matt to ask if it's possible to relocate the cabinet to the right side of the mill like the Tormach 1100, also for the back wall clearance if I didn't relocate.  

Matts reply was:

_As far as the back cabinet, I have had people take it off and put it in a different location, but that takes quite a bit of work. Not impossible, really its just extending the wires for the axis motors and a few others for various controls.

The cabinet doors are about 13” Wide, so you’d want about that much room in the back to be able to open them up all the way.
_
I then asked Matt for any tips or hints to make it easier.
_The only tip I can really say is do one wire at a time, then it should be no problem._

Finally, I asked Matt if doing so would void the warranty.

_no it doesn’t void the warranty, unless it’s a part directly affected by that, like if you cross wires and something burns up, then yes it would affect that, but in general, no, just moving the cabinet like that doesn’t void the whole warranty at all._ 

So far the pre-sale experience with Precision Matthews as been great. I'm hoping for the same experience after the sale.

Anyway, has anybody relocated their electronics cabinet?  Did you run into any issues? 

Finally, since my mill won't arrive for 4 or 6 weeks, I would appreciate it if a member would take some detailed pictures of electronics cabinets and if possible the wiring. Different angles would be great.  I would like to finalize the mill position in advance of delivery and if I will relocate the cabinet or not.

Thanks in advance for your help.

Rod in San Francisco


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## cut2cut

rodjava said:


> I'm placing my order the the PM-940 cnc tomorrow.  My original plan was to place it up against a wall.  Then I realized that the service electronic cabinet is in the back. I contacted Matt to ask if it's possible to relocate the cabinet to the right side of the mill like the Tormach 1100, also for the back wall clearance if I didn't relocate.
> 
> Matts reply was:
> 
> _As far as the back cabinet, I have had people take it off and put it in a different location, but that takes quite a bit of work. Not impossible, really its just extending the wires for the axis motors and a few others for various controls.
> 
> The cabinet doors are about 13” Wide, so you’d want about that much room in the back to be able to open them up all the way.
> _
> I then asked Matt for any tips or hints to make it easier.
> _The only tip I can really say is do one wire at a time, then it should be no problem._
> 
> Finally, I asked Matt if doing so would void the warranty.
> 
> _no it doesn’t void the warranty, unless it’s a part directly affected by that, like if you cross wires and something burns up, then yes it would affect that, but in general, no, just moving the cabinet like that doesn’t void the whole warranty at all._
> 
> So far the pre-sale experience with Precision Matthews as been great. I'm hoping for the same experience after the sale.
> 
> Anyway, has anybody relocated their electronics cabinet?  Did you run into any issues?
> 
> Finally, since my mill won't arrive for 4 or 6 weeks, I would appreciate it if a member would take some detailed pictures of electronics cabinets and if possible the wiring. Different angles would be great.  I would like to finalize the mill position in advance of delivery and if I will relocate the cabinet or not.
> 
> Thanks in advance for your help.
> 
> Rod in San Francisco


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## cut2cut

Hi Rod, 

I moved the electronics.   Later tonight I'll explain in detail.  Here is a picture of mine.  Besides elbow grease  and a day of work,  it's not too bad.   The box  is very very heavy, so you'll need two people minimum.  Some of the wires are just barely long enough but it's very doable.     When you are doing it it seems a little crazy,  but in the end it's worth it, imho.  

Jake


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## phazertwo

Looks pretty good.

What did you end up doing to get the spindle running with the nMotion?


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## cut2cut

phazertwo said:


> Looks pretty good.
> 
> What did you end up doing to get the spindle running with the nMotion?



Hey PhazerTwo,

These are the settings I am using so far. ( see pictures )
 1) Motor Output 2) Pulley setup, and finally 3) M-Codes to get it to spin.  ( I have not run any G-Code yet, hopefully tomorrow after I finish tramming.

The M-Code I used is M4 S400 ,  Then M5 to stop it.    S400 is telling it to spin at 400 rpm.  You must indicate the speed or it will not execute the M4 command.   While it is spinning, you can change the speed with a simple S(rpm) command.  M5 is used to stop it.  I believe M3 is for clockwise rotation.   Don't forget to choose the appropriate pulley for the rpm range you want.   Let me know if it isn't working after using these settings and I'll see if I missed anything.  

edit :  And if the spindle is spinning in the wrong direction its very possible you need to change your motor wiring.

btw,  I finally checked my backlash properly and found I have .001 in the X, and .002 in the Y and .001 in the Z.   I'm not terribly happy about the Y, maybe someday I'll get oversized balls for the Y ball nut and repack it.   When you get yours checked hopefully you can post your backlash results ?

Cheers,

Jake


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## DvCnewt

cut2cut said:


> (Edit)  It sounds like the orange wire is the culprit. You could verify this by opening the box that  houses the E-stop button itself to see if that orange wire is connected to the E -stop.   If all else fails try wiring the E stop directly to the Jamen controller card, to test it.



I opened up the box yesterday and there is no orange wire connected to e-stop button.  The button itself also checks out good.  
Will try to wire directly next.


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## cut2cut

rodjava said:


> .....
> Anyway, has anybody relocated their electronics cabinet?  Did you run into any issues?
> 
> Finally, since my mill won't arrive for 4 or 6 weeks, I would appreciate it if a member would take some detailed pictures of electronics cabinets and if possible the wiring. Different angles would be great.  I would like to finalize the mill position in advance of delivery and if I will relocate the cabinet or not.
> 
> Thanks in advance for your help.
> 
> Rod in San Francisco



The wires for almost everything are long enough,  but the flexible conduit is sometimes not long enough, so for a number of them I had to drill new holes in the electronics cabinet and pull sets of wires out and back through the conduit to relocate the hole which saved me from having to make new wires.  .  I put my main electrical cabinet box on the right of the mill which also required me to move the swing arm control box .  Because the large bundle of wires to that sub control box (  that swings , which houses the  on off switch , e -stop, light and coolant control )  it's very difficult to pull the wires back through, so I ended up going direct through the flex conduit instead of trying to pull it back through the pipe.
In the process I just took a ton of pictures and also made a wiring diagram ( DVCnewt, I'll post that here for you ) for that swing arm box.    If you put the main electrical cabinet on the left of the mill,  you could possibly avoid having to disassemble the swing arm box altogether.  I, however can't say the wires would be long enough.     I can bet you'd have to relocate the holes in the main cabinet as I had to.     I used a couple step drill bits ( see picture ) at their maximum diameter.

That being said,  all wires go through the terminal block,  so rewiring with longer wire when needed Wouldn't be a big deal.   Finding and purchasing the same  black rubberized  coated flexible metal conduit they used would make the job go pretty easy and stress free.   Still time consuming  however.   You'd also want some crimp wire connectors and a good crimper.

Edit,  I forgot to add one slightly difficult part of the process.  There are four hidden allen head bolts that hold the main electrical cabinet to the column of the mill.  There are four nuts on each corner of the panel of electronics ( see picture ).  You have to remove those four nuts and lean the interior panel of electrics forward to get access to those four Allen head bolts.  All the while keeping the weight of the box as you remove the four bolts.    As I said it's a two ( or even three man job.).

Ultimately your mill gets cosmetically beat up even if you are careful, which is hard to do with the weight being significant.   Why because of  the soft bondo / auto filler they use to smooth out the entire mills casting. It's thick and chips off fairly easily.  So when detaching stuff it chips off a lot.  My mill looks used at this point,  so don't think it's going to be a show piece after all is said and done.  But the shiny surfaces that matter look great.

..... if anyone wants a link to my unorganized and snap happy library of pictures just send me a private message.

Jake


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## phazertwo

cut2cut said:


> Hey PhazerTwo,
> 
> These are the settings I am using so far. ( see pictures )
> 1) Motor Output 2) Pulley setup, and finally 3) M-Codes to get it to spin.  ( I have not run any G-Code yet, hopefully tomorrow after I finish tramming.
> 
> The M-Code I used is M4 S400 ,  Then M5 to stop it.    S400 is telling it to spin at 400 rpm.  You must indicate the speed or it will not execute the M4 command.   While it is spinning, you can change the speed with a simple S(rpm) command.  M5 is used to stop it.  I believe M3 is for clockwise rotation.   Don't forget to choose the appropriate pulley for the rpm range you want.   Let me know if it isn't working after using these settings and I'll see if I missed anything.
> 
> edit :  And if the spindle is spinning in the wrong direction its very possible you need to change your motor wiring.
> 
> btw,  I finally checked my backlash properly and found I have .001 in the X, and .002 in the Y and .001 in the Z.   I'm not terribly happy about the Y, maybe someday I'll get oversized balls for the Y ball nut and repack it.   When you get yours checked hopefully you can post your backlash results ?
> 
> Cheers,
> 
> Jake



Have you been running with your X, Y, and Z on those settings?  That's not what I have...

Our spindle settings actually do match.  I thought you could just clikc the "Spindle CW" button to fire up the spindle...  I will give the G-code a shot and see if that fires it up.

PZ


----------



## cut2cut

phazertwo said:


> Have you been running with your X, Y, and Z on those settings?  That's not what I have...
> 
> Our spindle settings actually do match.  I thought you could just clikc the "Spindle CW" button to fire up the spindle...  I will give the G-code a shot and see if that fires it up.
> 
> PZ



After shooting this video to ensure the orientation is correct I took pictures of my settings again ( enclosed ).   What I created in fusion 360 came out exactly as it should have.

I am able to fire up the spindle with the Spindle CW button.   Not sure why you cannot.   I did have to reverse two of the motor wires (from the VFD ) to get it to spin in the correct direction.  Maybe hit the reset button next to the Spindle CW button to get the default 100%.    Or try the M-Codes... for example :  M3 S200.
Be sure to set the pulley configuration too.

Jake


----------



## phazertwo

NICE!

My spindle is still not working.  On your ports and pins config page, what are your settings on the spindle setup tab?  Also, on your motor tuning config page, what are your settings on the spindle tab?

At this point I have uninstalled and am re-installing M3.  Hopefully I will get a chance to try it out tonight.

Thanks


----------



## phazertwo

THIS POST WAS A ERROR...  ADMIN PLEASE DELETE


----------



## cut2cut

phazertwo said:


> NICE!
> 
> My spindle is still not working.  On your ports and pins config page, what are your settings on the spindle setup tab?  Also, on your motor tuning config page, what are your settings on the spindle tab?
> 
> At this point I have uninstalled and am re-installing M3.  Hopefully I will get a chance to try it out tonight.
> 
> Thanks



Ok,  here are ALL my current mach 3 settings including the specific ones you asked for  +  pictures of my VFD wiring and the controller wiring.  The only thing that isn't working is soft limits.    Hope you can get to the bottom of the spindle issue soon.   

Jake


----------



## cut2cut

also, a picture of the wires in the motors electrical box from the factory.  I reversed the U1 and W1 from what is shown so my motor would spin the correct direction.

Jake


----------



## cut2cut

DvCnewt said:


> I opened up the box yesterday and there is no orange wire connected to e-stop button.  The button itself also checks out good.
> Will try to wire directly next.



Here are some pictures that might help figure out if your wiring is correct.  You could also change the pin that the e-Stop goes to on the controller board ( if you think its a bad input ).  Then change the pin designation in Mach 3 for the Estop button.


----------



## phazertwo

Well I got my spindle running last night.  Stupid me forgot to un-check the de-activate spindle relays box... Fired right up and seems to be working great, I still need to get my digital tach out and see how accurate it is, but for now it's spinning.

However I have run into more serious issues.  The mill is not running consistantly if I run it from gcode, or tell it to go to zero.  It starts and stops about every second, which and it doesn't seem to use the deaccel or accel to do it...  What am I missing here.  My settings are identical to Cut2cuts...

Read here for more. http://www.hobby-machinist.com/threads/pm-940-cnc-jumping-with-gcode.55611/

PZ


----------



## cut2cut

phazertwo said:


> PZ



Try turning off the spindle again to see if it's electrical noise from the VFD causing the issues ?

Jake


----------



## phazertwo

It was doing it with the spindle off too.

Turns out it was the buffer time on the nMotion config screen...  Looks like you're running 759ms, mine is running about 2000ms.

PZ


----------



## cut2cut

phazertwo said:


> It was doing it with the spindle off too.
> 
> Turns out it was the buffer time on the nMotion config screen...  Looks like you're running 759ms, mine is running about 2000ms.
> 
> PZ



So you are running a larger buffer and that solved it.  Good to know.... 

Mine was automagically set, probably the default.  I'm using a computer running widows XP, btw , which may have less overhead / more efficient.  And coupled with a possibly faster computer I can get away with the default settings.


----------



## rodjava

cut2cut said:


> View attachment 225544
> 
> 
> 
> 
> 
> 
> 
> 
> 
> Hi Rod,
> 
> I moved the electronics.   Later tonight I'll explain in detail.  Here is a picture of mine.  Besides elbow grease  and a day of work,  it's not too bad.   The box  is very very heavy, so you'll need two people minimum.  Some of the wires are just barely long enough but it's very doable.     When you are doing it it seems a little crazy,  but in the end it's worth it, imho.
> 
> Jake




Jake,
I can't thank you enough for sharing how you relocated the electrical enclosure.   I'm expecting my 940 cnc in about 4-5 weeks and will likely do the same as you.  

Rod in San Francisco


----------



## phazertwo

cut2cut said:


> So you are running a larger buffer and that solved it.  Good to know....
> 
> Mine was automagically set, probably the default.  I'm using a computer running widows XP, btw , which may have less overhead / more efficient.  And coupled with a possibly faster computer I can get away with the default settings.



Yeah, I tried it with the same buffer that you have and it still had the same problem.  I wonder if this has more to do with the speed of my computer.  The computer I have on the mill right now is pretty weak, even as far as XP machines go.  I have another one that I can get setup to run XP, I'll probably start that process over the weekend, along with transferring all of the settings. 

PZ


----------



## cut2cut

rodjava said:


> Jake,
> I can't thank you enough for sharing how you relocated the electrical enclosure.   I'm expecting my 940 cnc in about 4-5 weeks and will likely do the same as you.
> 
> Rod in San Francisco



No problem,  let me know if you need any more detail and I'll try to help.

Jake


----------



## cut2cut

phazertwo said:


> Yeah, I tried it with the same buffer that you have and it still had the same problem.  I wonder if this has more to do with the speed of my computer.  The computer I have on the mill right now is pretty weak, even as far as XP machines go.  I have another one that I can get setup to run XP, I'll probably start that process over the weekend, along with transferring all of the settings.
> 
> PZ


EDIT :  Retraction !  The hiccups were actually bad G-Code from FUSION 360 !

_Well,  I just experienced the same thing you had happen , "hiccups" while running G code.   Adding to the buffer didn't get rid of it completely.  It has only shown up during short segments with a lot of small lines of code with quick changes of direction.  When it happens the spindle speed also increases and then backs down until the next "hiccup".  Even if this is easily curable _I'll be accelerating my move away from Mach 3+usb to LinuxCNC via ethernet or PCI interface.  

Jake


----------



## phazertwo

Now I have a new problem.  If I set x0y0 at somewhere, then jog atleast an inch away from that in both x and y, then run a G0X0Y0... it never returns to quite the same spot.  It's usually .05-.4" off on the DRO.  This doesn't make any sense to me, even if it is missing steps the DRO should still go to zero correct?

Could you do a little test of the above Jake and let me know what yours does?

PZ


----------



## cut2cut

phazertwo said:


> Now I have a new problem.  If I set x0y0 at somewhere, then jog atleast an inch away from that in both x and y, then run a G0X0Y0... it never returns to quite the same spot.  It's usually .05-.4" off on the DRO.  This doesn't make any sense to me, even if it is missing steps the DRO should still go to zero correct?
> 
> Could you do a little test of the above Jake and let me know what yours does?
> 
> PZ



I tested mine 6 times exactly as you asked.      When instructed via the G0x0y0 command Mach3's DRO returned back to 0.0000 most times and a few times the DRO would show .0001 of true "Zero".     Yeah,  I agree, since it is an open system, I would think Mach3 should "think" it moved back to exact ZERO every time.     

Jake


----------



## phazertwo

Thanks Jake!

Well, I'm uninstalling and reinstalling Mach 3 for round 3...  I really am at a loss to what I am doing wrong here, unless running the demo version is my problem, though I have not ready anything that would suggest it would.

PZ


----------



## Davd Flowers

I think that the .0001 may be mach trying to hit the best possible mark with what it has to work with.
Basically something like this....maybe?
1.8 degree steppers at half step is 400 steps per revolution. Coupled to a 5mm pitch ball screw which travels .19685" per revolution or .000492125 per half step.  so if your asking it to make .001" it can never really move the .001" so it comes as close as it can????


----------



## cut2cut

Yeah,  mine is possibly due to an acceptable "rounding" type error ,  but PhazerTwo's is far beyond a rounding error, right !!?


----------



## phazertwo

Davd Flowers said:


> I think that the .0001 may be mach trying to hit the best possible mark with what it has to work with.
> Basically something like this....maybe?
> 1.8 degree steppers at half step is 400 steps per revolution. Coupled to a 5mm pitch ball screw which travels .19685" per revolution or .000492125 per half step.  so if your asking it to make .001" it can never really move the .001" so it comes as close as it can????



Yes, this is correct.  With 8000 Steps/in I should be able to get a resolution of 0.000125.



cut2cut said:


> Yeah,  mine is possibly due to an acceptable "rounding" type error ,  but PhazerTwo's is far beyond a rounding error, right ?



FAR beyond.  When I am 0.050 off that is 400x the rounding error I should be getting...  Not acceptable.

Last night I re-installed Mach 3 and started playing with the buffer time.  If I set the buffer time high then my error goes up, and my "jumping" goes away.  If I set the buffer low my error goes down but the "jumping" shows back up.  Hopefully I can find an acceptable balance of no jumping and accurate enough.  All and all, I am very unimpressed with the nMotion controller which is super unfortunate because it seems to be a capable unit short of its few issues.

PZ


----------



## Davd Flowers

phazertwo said:


> Yes, this is correct.  With 8000 Steps/in I should be able to get a resolution of 0.000125.
> 
> 
> 
> FAR beyond.  When I am 0.050 off that is 400x the rounding error I should be getting...  Not acceptable.
> 
> Last night I re-installed Mach 3 and started playing with the buffer time.  If I set the buffer time high then my error goes up, and my "jumping" goes away.  If I set the buffer low my error goes down but the "jumping" shows back up.  Hopefully I can find an acceptable balance of no jumping and accurate enough.  All and all, I am very unimpressed with the nMotion controller which is super unfortunate because it seems to be a capable unit short of its few issues.
> 
> PZ



And this is repeatable on all 3 axis??


----------



## phazertwo

Davd Flowers said:


> And this is repeatable on all 3 axis??



I assume you're talking about my statement on the buffering time vs accuracy.  So far yes, it is repeatable on all 3 axis.  I only tested for ~5min but every time I sent it to a random x,y,z position running a low buffer time it would get there within 0.0001".  The further I cranked the buffer time up the larger that 0.0001" got.  I probably won't have time to do more testing until Wednesday night, I will post up more results.

HOPEFULLY I can actually run some g-code on Wednesday (just a marker in the spindle)!

PZ


----------



## cut2cut

I found the problem that was causing me "hiccups".    Fusion 360 created some VERY strange G-Code...   Note to self, always check the G-code for anomalies if the mill is acting strange during a job.  So I edited my above comment that pointed the blame at the 940cnc 2017 revision USB controller hardware  Nevermind....

Also,  briefly I just tried a newer i5  64 bit computer with a fresh install of windows 7 professional 64 bit and downloaded and installed a demo copy of Mach3.    Seemed to work quite well and while using the default buffer size in the nMotion plugin configuration settings.
I tested the g-code that hiccuped, and also moved the x and y around after zeroing, and then used the G0X0Y0 command and it landed at .0000 or .0001 every time.  

Jake


----------



## phazertwo

cut2cut said:


> I found the problem that was causing me "hiccups".    Fusion 360 created some VERY strange G-Code...   Note to self, always check the G-code for anomalies if the mill is acting strange during a job.  So I edited my above comment that pointed the blame at the 940cnc 2017 revision USB controller hardware  Nevermind....
> 
> Also,  briefly I just tried a newer i5  64 bit computer with a fresh install of windows 7 professional 64 bit and downloaded and installed a demo copy of Mach3.    Seemed to work quite well and while using the default buffer size in the nMotion plugin configuration settings.
> I tested the g-code that hiccuped, and also moved the x and y around after zeroing, and then used the G0X0Y0 command and it landed at .0000 or .0001 every time.
> 
> Jake



This is good to know.  I have a much better computer just sitting around that I can load XP on and give Mach 3 another shot, hopefully with a smaller buffer.  I'll have to start the install process tomorrow and see how far I get.

PZ


----------



## phazertwo

Made my first chips last night!  Didn't take a picture because there wasn't really anything to take a picture of.  I simply ran G1 codes around a block of aluminum for no reason other than to make some chips and say that I used my mill!

Hopefully I will get a little bit of play time over the next few days and actually cut something out.

PZ


----------



## rodjava

cut2cut said:


> Ok, sorry for the delay.  Here are the pendant pictures I promised.
> 
> I'm still getting the software configured little by little.  A fellow pm-940CNC owner has helped me test the spindle, and also showed me some wiring for things like the coolant pump that were not designated anywhere.
> 
> X Y and Z function so far, so the new controller appears to be functioning.
> 
> So far I love the rigidity and smooth ground ways.  I have yet to check for backlash and such, but the fit feels good so far.   I do have a knocking sound in the Z that I need to inspect.  I believe it has to do with the slop in the hand crank gear interface with the ball screw...or possibly the screws holding the ball nut are not tight.  If it is the hand crank slop I'll probably remove the hand crank assembly entirely, unless it serves to keep the head from creeping down on its own weight ?
> 
> Cheers,
> 
> Jake
> 
> View attachment 225057
> View attachment 225058




Jake,
I'm trying to figure out the wiring for the coolant pump too.  Any pictures or info how the 3 wires connect to the pump? I emailed Matt, but it's Sunday.

Rod in San Francisco


----------



## cut2cut

rodjava said:


> Jake,
> I'm trying to figure out the wiring for the coolant pump too.  Any pictures or info how the 3 wires connect to the pump? I emailed Matt, but it's Sunday.
> 
> Rod in San Francisco



I haven't actually wired it but I asked a fellow with the 2016 revision of the pm 940-cnc'  if he could send his wiring.  I don't recall if the terminal block  looks exactly the same but here is what he sent me.
If you get yours wired up and working please send a picture of your pump wiring !

Jake


----------



## cody.williams

Hey Guys

So long story short, I'm a new employee at a small lab. They had purchased a PM-940M a few years back and never had it set up. This past week I have been in charge of setting it up. I've been able to get the mill to jog in all directions but I have not been able to get the spindle to turn at all. I've tried everything listed in this thread, but without any luck. I did notice the VFD throwing a AErr code which directed my to check the ACI Wiring. I checked the M1 and M2 wires and everything seemed fine, still getting the error...

I also have been having problems with the physical E-Stop Button. It is wired to I11 on the JNC-40M motion controller, I have the input mapped to 11 on Mach3, yet in the diagnostics page when its pressed Output 3 starts flashing. 

I am new to this CNC thing and at a complete loss. Any and all suggestions will be appreciated


----------



## cut2cut

I don't have the older controller so I doubt I can help you Cody,  however I've recently converted my mill to use Linux CNC which required new electronics / controller,  so if you ever need or want to swap out for the latest ( 2017 revision ) controller for the pm940 cnc , I will be selling my factory nMotion controller with pendant.
I also am going to belt drive and in the process will have the spindle motor for sale too.  For anyone interested,  I suppose it's best to send me a private message.

Jake


----------



## phazertwo

cut2cut said:


> I don't have the older controller so I doubt I can help you Cody,  however I've recently converted my mill to use Linux CNC which required new electronics / controller,  so if you ever need or want to swap out for the latest ( 2017 revision ) controller for the pm940 cnc , I will be selling my factory nMotion controller with pendant.
> I also am going to belt drive and in the process will have the spindle motor for sale too.  For anyone interested,  I suppose it's best to send me a private message.
> 
> Jake



Hows the new setup?  Which controller did you end up with?

I have been battling more with the buffer time... and somewhat frequently it still seems to just not do what I want it to do...


----------



## cody.williams

Hi,

Is there any way anyone could send me their parameters on their VFD. Matt seemed to indicate that with the machine not running for a long time, the internal memory on the VFD might have went blanked and the parameters reset.


----------



## cut2cut

phazertwo said:


> Hows the new setup?  Which controller did you end up with?
> 
> I have been battling more with the buffer time... and somewhat frequently it still seems to just not do what I want it to do...



I am now using Linux CNC with the Mesa 7i76E ( the E stands for ethernet ).  It wasn't an easy as "plug and play" because installing LinuxCNC was a bit of a hassle and I had to rely on my brothers help quite a bit with re-wiring ( of the relays mostly ) for the 7i76e  and the VFD to talk to each other.  Also the limit and home switches needed a bit of detail too ( basically the common leg had to be powered ). 

Last time I used the mill the spindle was getting quite warm and now it feels very tight, so I'm going to have to take it apart to make sure its greased properly and not set too tight.   

Jake


----------



## phazertwo

cut2cut said:


> I am now using Linux CNC with the Mesa 7i76E ( the E stands for ethernet ).  It wasn't an easy as "plug and play" because installing LinuxCNC was a bit of a hassle and I had to rely on my brothers help quite a bit with re-wiring ( of the relays mostly ) for the 7i76e  and the VFD to talk to each other.  Also the limit and home switches needed a bit of detail too ( basically the common leg had to be powered ).
> 
> Last time I used the mill the spindle was getting quite warm and now it feels very tight, so I'm going to have to take it apart to make sure its greased properly and not set too tight.
> 
> Jake



That is awesome.  You'll have to keep us updated on how it's working out.

What made you choose the Mesa over the SmoothStepper?

PZ


----------



## cut2cut

phazertwo said:


> That is awesome.  You'll have to keep us updated on how it's working out.
> 
> What made you choose the Mesa over the SmoothStepper?
> 
> PZ



The Mesa is supposed to be solid hardware and also used by Tormach so if I ever try to use pathpilot control software it will be less struggle to implement it, theoretically !
Jake


----------



## phazertwo

I just glanced over the manual for the Mesa... a step far above the nMotion for sure.  It looks like the hardest thing to over come would be the spindle speed control, going from PWM to essentially a POT.  How is linux CNC vs Mach 3?  I am VERY interested in changing to Linux, so don't hold back on review!

PZ


----------



## cut2cut

Yeah,  I will.  Probably will start a new thread though, so as to not hijack this one.  
The wiring isn't very difficult now that I have a schematic.  I'll share that too.  

Jake


----------



## cut2cut

Hi,  sorry, I haven't had much time to work on the mill but just yesterday I installed AC bearings in the spindle.   I don't know if it's successful yet as I haven't checked runout tand actually cut anything but I do want to caution others about something I ran across without regard to the bearings you use.  When I tore apart the spindle the interior of the spindle cavity had loose   "scale" from the casting process.  While I had it apart  I used a wire wheel on an extension to loosen up and remove the existing scale so it won't come off anymore and easily get  into my fresh bearings.  

Jake


----------



## phazertwo

You're going to have the baddest 940 CNC out there...  Have you thought about upgrading your motors at all?

PZ


----------



## cut2cut

..... thought about clearpath servos,  but that's some money right there !!!

But I actually have already changed the spindle motor...


----------



## rodjava

I would like to change my spindle motor at some point. It would be great if someone would post how they did it and the pros and cons of the install.

Rod in San Francisco


----------



## cut2cut

I started a thread so I wouldn't hijack this one since its about Modifications to the "pre-assembled" mill.

Go here to check it out : 

http://www.hobby-machinist.com/threads/my-pm-940-cnc-modifications.57976/#post-476885

Cheers,

Jake


----------



## chocadile

Hi everyone,

I was hoping I could get some help with Homing switches for my machine.  I've been trying to get the 940 cnc to perform the ref all home, and my switches are not working as they should be.  When in the diagnostics screen the light comes on when I press the buttons manually.  Although when I try to home the machine it travels pass the stops as if they're not being recognized. 

My limit switches are working just fine.  When those are pressed the machine stops jogging the table and z-axis.

I'm out of ideas as to what is causing my home switches to not be recognized during the homing process.  I've looked over Cut2Cut's set up screen shots and it would appear we have the same settings.  Any help would be greatly appreciated.

I can provide any additional info if it'll help diagnose the problem or at least point me in the right direction.  Thanks


----------



## TomS

chocadile said:


> Hi everyone,
> 
> I was hoping I could get some help with Homing switches for my machine.  I've been trying to get the 940 cnc to perform the ref all home, and my switches are not working as they should be.  When in the diagnostics screen the light comes on when I press the buttons manually.  Although when I try to home the machine it travels pass the stops as if they're not being recognized.
> 
> My limit switches are working just fine.  When those are pressed the machine stops jogging the table and z-axis.
> 
> I'm out of ideas as to what is causing my home switches to not be recognized during the homing process.  I've looked over Cut2Cut's set up screen shots and it would appear we have the same settings.  Any help would be greatly appreciated.
> 
> I can provide any additional info if it'll help diagnose the problem or at least point me in the right direction.  Thanks



Assuming you are using Mach3, what version do you have loaded?  I had the same problem using ver. 066.  Reloaded 062 and it's been working fine for the last 2 to 3 years.


----------



## chocadile

TomS said:


> Assuming you are using Mach3, what version do you have loaded?  I had the same problem using ver. 066.  Reloaded 062 and it's been working fine for the last 2 to 3 years.



Hi Tom,

I am running Mach3 version R3.043.066  I will give loading .062 a shot and see how that works.  Thanks for suggestion I'll post back and let you know how it goes.


----------



## chocadile

I was able to download and install .062.  I backed up my previous settings and loaded that .xml file into my .062 Mach3 install and I'm still experiencing the same problem with the home switches.  Unfortunately I am not able to check any of them but the z-axis because that is the first axis to home.  With it not recognizing the home switch, stopping, and zeroing I can not test the x-y axis for function.  I have to e stop the machine because the z-axis keeps traveling north.  The only test I can perform is at the diagnostics tab where I can see the LEDs lit when pressing the home switches.  I am now going back and forth with Mach3 support to try and get this figured out.  

I've emailed them my .xml setup file, one thing they mentioned were my input pins being setup incorrectly.  I have my input, and all of mach3 set up the same a CUT2CUT, I believe.  I have not had any other problems with the machine so far running these settings.  I asked why the limit switches would work and not the home switches if the input pins were incorrect.  I them emailed the the nmotion.dll file to hopefully get some clarification. 

Thank you Tom for the help I'll continue to update as I go along.  Hoping the next post will be about my problems being resolved haha.


----------



## TomS

chocadile said:


> I was able to download and install .062.  I backed up my previous settings and loaded that .xml file into my .062 Mach3 install and I'm still experiencing the same problem with the home switches.  Unfortunately I am not able to check any of them but the z-axis because that is the first axis to home.  With it not recognizing the home switch, stopping, and zeroing I can not test the x-y axis for function.  I have to e stop the machine because the z-axis keeps traveling north.  The only test I can perform is at the diagnostics tab where I can see the LEDs lit when pressing the home switches.  I am now going back and forth with Mach3 support to try and get this figured out.
> 
> I've emailed them my .xml setup file, one thing they mentioned were my input pins being setup incorrectly.  I have my input, and all of mach3 set up the same a CUT2CUT, I believe.  I have not had any other problems with the machine so far running these settings.  I asked why the limit switches would work and not the home switches if the input pins were incorrect.  I them emailed the the nmotion.dll file to hopefully get some clarification.
> 
> Thank you Tom for the help I'll continue to update as I go along.  Hoping the next post will be about my problems being resolved haha.



If you go to the Diagnostics screen you can Home each axis individually.  Look in the upper left corner.

Sorry to hear loading ver. 062 didn't solve your problem.  Hopefully the Mach Support guys can fix it.  If not, post a screen shot of your input signals and maybe we can help.


----------



## chocadile

TomS said:


> If you go to the Diagnostics screen you can Home each axis individually.  Look in the upper left corner.
> 
> Sorry to hear loading ver. 062 didn't solve your problem.  Hopefully the Mach Support guys can fix it.  If not, post a screen shot of your input signals and maybe we can help.



Hi Tom,

I found the ref tabs in the diagnostic screen and started trying to home the axis one by one.  I found that the Z and X axis still do not want to cooperate.  The Y axis on the other hand homes and zeros just fine.  This is very interesting.  At least I'm a third of the way there now haha.  I've taken screen shots of some of my settings that I hope will shed some light on my problems.   

If there are any other set up tabs you'd like screen shots of please let me know.  I just grabbed the ones I thought would be most helpful.  

Thank you again for the help Tom it's greatly appreciated.


----------



## TomS

chocadile said:


> Hi Tom,
> 
> I found the ref tabs in the diagnostic screen and started trying to home the axis one by one.  I found that the Z and X axis still do not want to cooperate.  The Y axis on the other hand homes and zeros just fine.  This is very interesting.  At least I'm a third of the way there now haha.  I've taken screen shots of some of my settings that I hope will shed some light on my problems.
> 
> If there are any other set up tabs you'd like screen shots of please let me know.  I just grabbed the ones I thought would be most helpful.
> 
> Thank you again for the help Tom it's greatly appreciated.



Before I start offering suggestions a couple of questions.  Do you have separate limit and home switches?  Are your switches wired in series?  Looking at your Inputs screen shot it looks like you have your switches wired to individual inputs.


----------



## chocadile

TomS said:


> Before I start offering suggestions a couple of questions.  Do you have separate limit and home switches?  Are your switches wired in series?  Looking at your Inputs screen shot it looks like you have your switches wired to individual inputs.



Tom,

Yes I have separate home and limit switches.  I do believe they are wired in series. I have attached pics of my home and limit switches.


----------



## TomS

chocadile said:


> Tom,
> 
> Yes I have separate home and limit switches.  I do believe they are wired in series. I have attached pics of my home and limit switches.



Thanks for the clarifications.  What I've read is these Jamen boards can test your patience. 

Take a look at your Inputs screen.  There is a note that says you can use only pin numbers 10 thru 13 and 15 as inputs.  You are using pin numbers 1 thru 6.  I'm thinking Mach is looking for signals from pins 10-13 and 15 and not seeing the signals from pins 1 - 6.  Also your Port# is set as 2.  Reading through the attached Jamen manual it should be set to Port #1.  You need to determine the pin number on your breakout board that the limit and home switches are wired to then change your Input screen to match.  Take it a step at a time so you know what change solved the problem.

A close up picture of your breakout board showing pins numbers would be helpful.

Edit - if your switches are wired in series then you will be using two input pins, one for your limit switches and one for your homing switches.  Unless all of your switches are wired together in series in which case you will be using one input pin.


----------



## chocadile

TomS said:


> Thanks for the clarifications.  What I've read is these Jamen boards can test your patience.
> 
> Take a look at your Inputs screen.  There is a note that says you can use only pin numbers 10 thru 13 and 15 as inputs.  You are using pin numbers 1 thru 6.  I'm thinking Mach is looking for signals from pins 10-13 and 15 and not seeing the signals from pins 1 - 6.  Also your Port# is set as 2.  Reading through the attached Jamen manual it should be set to Port #1.  You need to determine the pin number on your breakout board that the limit and home switches are wired to then change your Input screen to match.  Take it a step at a time so you know what change solved the problem.
> 
> A close up picture of your breakout board showing pins numbers would be helpful.
> 
> Edit - if your switches are wired in series then you will be using two input pins, one for your limit switches and one for your homing switches.  Unless all of your switches are wired together in series in which case you will be using one input pin.



Hi Tom,

My machine is using the nMotion board as the control board.  I believe this came in the newer versions of the PM-940-CNC.


----------



## TomS

chocadile said:


> Hi Tom,
> 
> My machine is using the nMotion board as the control board.  I believe this came in the newer versions of the PM-940-CNC.



I have no experience with the nMotion board but let's see if we can make it work.  Here's a few suggestions that you can try.  Keep track of the changes you make so you can revert back to the original configuration if necessary.

1.  On the nMotion Status and Config screen lower left corner there are check boxes for homing switches.  Put a check in the X, Y and Z boxes and see what happens.

2.  In Mach3 configuration Inputs screen change the Port# to Port 1.  

3.  Your limit and home switches are connected to Pins 1 thru 6 on your controller.  Mach 3 recognizes pins 10 thru 13 and pin 15 as inputs.  It appears your switches are not wired in series so you don't have enough input pins available for all your switches.  You can wire them in series then connect them to two of your input pins (one pin for limits and one for homing), then change Mach3 configuration to reflect the pin numbers you are using.

Let me know how this works out.


----------



## TomS

Anything to report?


----------



## qualitymachinetools

Thank you so much for the replies Tom, hopefully that will get him going! I really need to get a machine set up again so I keep up on them like you guys do, I rarely get to run anything anymore.


----------



## TomS

qualitymachinetools said:


> Thank you so much for the replies Tom, hopefully that will get him going! I really need to get a machine set up again so I keep up on them like you guys do, I rarely get to run anything anymore.



My pleasure.  It's my way of giving back to this forum.


----------



## chocadile

Hi Tom,

Sorry I went dark for a little while, I've had other things occupying my time here at work.  We are a small shop and the Mill has been a side project for us.  I am now getting some more time to focus on the Mill set up.  Thank you for the input it's greatly appreciated.  My responses are under you suggestions.



TomS said:


> I have no experience with the nMotion board but let's see if we can make it work.  Here's a few suggestions that you can try.  Keep track of the changes you make so you can revert back to the original configuration if necessary.
> 
> 1.  On the nMotion Status and Config screen lower left corner there are check boxes for homing switches.  Put a check in the X, Y and Z boxes and see what happens.
> 
> When I attempt to check those boxes in the configuration screen, The check will appear when I click the box.  Then quickly the check will disappear.  The boxes will not remain checked.
> 
> 2.  In Mach3 configuration Inputs screen change the Port# to Port 1.
> 
> I gave this a try, when changing my Port# to Port1 my limit and home switches do not work at all.  In the diagnostics screen the light will no longer come on when the switches are being actuated.  I did this for only the home switches  Returning the Port# to Port2 show all switches lighting up in the diagnostics screen when actuated.
> 
> 3.  Your limit and home switches are connected to Pins 1 thru 6 on your controller.  Mach 3 recognizes pins 10 thru 13 and pin 15 as inputs.  It appears your switches are not wired in series so you don't have enough input pins available for all your switches.  You can wire them in series then connect them to two of your input pins (one pin for limits and one for homing), then change Mach3 configuration to reflect the pin numbers you are using.
> 
> Re-wiring the switches is definitely intimidating for me. Not something I've done before but, willing to  give it a try.  My only concern is from what I've read on the forum, it seems other users have had success without having to rewire the home/limit switches.  My other concern is modifying the machine and doing something that can't be reversed.  I guess returning the switches to the current set up shouldn't be to difficult if wiring them in series doesn't pan out?
> 
> Let me know how this works out.



Thanks again Tom


----------



## TomS

chocadile said:


> Hi Tom,
> 
> Sorry I went dark for a little while, I've had other things occupying my time here at work.  We are a small shop and the Mill has been a side project for us.  I am now getting some more time to focus on the Mill set up.  Thank you for the input it's greatly appreciated.  My responses are under you suggestions.
> 
> 
> 
> Thanks again Tom



I've read what I could find on this forum and it appears your switch wiring is correct.  Without a manual it's hard for me to understand what's causing your problems and searching the net there is virtually no information out there.  So at this point I'm at a loss.  You may want to PM these two other PM-940 CNC owners PhazerTwo and cut2cut and get a dialogue going with them.  They appear to have worked through some of the problems you are facing.  

Probably not what you want to hear but many others have replaced their nmotion controller with a more mainstream controller.  I have a PM-932 that I converted and recently changed out my electronics with a PMDX-126 breakout board, a Warp 9 ethernet smoothstepper and PMDX-107 spindle control board.  This setup work flawlessly.


----------



## Skookum

I've been trying to figure out the 940m cnc and it's been strange. The steppers are getting VERY hot after only ~20 minutes running. I checked the stepper drivers and they're set to 10000 steps per revolution, but I only get accurate movement when I set mach3 to 8000 steps. 

Also, loading gcode that contains arcs (G02, G03) results in incorrect shapes being drawn and cut.

I feel like I should be blaming the nmotion controller, but if anyone has some tips, I'd really appreciate it.


----------



## phazertwo

Skookum said:


> I've been trying to figure out the 940m cnc and it's been strange. The steppers are getting VERY hot after only ~20 minutes running. I checked the stepper drivers and they're set to 10000 steps per revolution, but I only get accurate movement when I set mach3 to 8000 steps.
> 
> Also, loading gcode that contains arcs (G02, G03) results in incorrect shapes being drawn and cut.
> 
> I feel like I should be blaming the nmotion controller, but if anyone has some tips, I'd really appreciate it.



First question: When was your machine received, and can you post a pic from inside the cabinet?  I know there has been some changes and we have seen these changes even in machines that were all received in 2017.  Not a bad thing, they're just making improvements.

Mine, and from what I remember others with 940 CNC's as well, came setup for 8000 steps/rev.  I would assume that you have DM860H drives, so your dip switches should be set like this for 8k steps/rev.






Hope this helps.

If you have any video or pics of the machine making the "incorrect shapes" that would be helpful.  My gut says that you are missing steps but who knows.

Also what CAM software are you using, and what post processor?

PZ


----------



## Skookum

phazertwo said:


> First question: When was your machine received, and can you post a pic from inside the cabinet?  I know there has been some changes and we have seen these changes even in machines that were all received in 2017.  Not a bad thing, they're just making improvements.
> 
> Mine, and from what I remember others with 940 CNC's as well, came setup for 8000 steps/rev.  I would assume that you have DM860H drives, so your dip switches should be set like this for 8k steps/rev.
> 
> 
> 
> 
> 
> Hope this helps.
> 
> If you have any video or pics of the machine making the "incorrect shapes" that would be helpful.  My gut says that you are missing steps but who knows.
> 
> Also what CAM software are you using, and what post processor?
> 
> PZ



Got it late 2017, maybe November or December. The spindle also seems to be underpowered compared to an older version of the 940 that a colleague has.

Using Vectric Aspire, and so far the only post-processor that works there is 'Plain G-Code', trying to use 'Mach 2/3 Arcs' results in incorrect curves.

Spent all day today messing with steps, got it moving nicely now, but I bet there still will be the problem with arcs.

For reference, I set the drivers to 20,000 pulses/rev and I think Mach3 is set to 100,000 steps per unit.
I also lowered the amperage.

After a 90 minute job, the steppers only reached a max temp of about 65C, compared to 80C after 20 minutes.

I'll post more tomorrow and some pictures of the errors I see.


----------



## phazertwo

20k steps/rev is A LOT!  My drives are set to 1600 and 2000 would be the max that I would go.  At 2000 steps/rev, each step is 0.0001" linear movement of the table.  At 20k steps/rev your table is moving 0.00001" per step.... or one, one-hundred-thousands of an inch... Which is an insane number, especially considering the run out on the spindle bearings is only rated at like 0.0015" or 150 x larger than your step distance.

Also, just to run 100IPM your going to need 166khz/axis.  I can't imagine that the nMotion/M3 handles that well.  I would try bumping it down to 2k steps/rev and give it a shot, that essentially reduces the load on the nMotion/M3 by 10.  Also, stepper motors get hot, I have never measured mine so I don't know how hot they get, but they feel toasty.  Due to the nature of a stepper, heating will always be an issue.

Is there a reason you are not using Fusion 360 for CAM?

PZ


----------



## Skookum

phazertwo said:


> 20k steps/rev is A LOT!  My drives are set to 1600 and 2000 would be the max that I would go.  At 2000 steps/rev, each step is 0.0001" linear movement of the table.  At 20k steps/rev your table is moving 0.00001" per step.... or one, one-hundred-thousands of an inch... Which is an insane number, especially considering the run out on the spindle bearings is only rated at like 0.0015" or 150 x larger than your step distance.
> 
> Also, just to run 100IPM your going to need 166khz/axis.  I can't imagine that the nMotion/M3 handles that well.  I would try bumping it down to 2k steps/rev and give it a shot, that essentially reduces the load on the nMotion/M3 by 10.  Also, stepper motors get hot, I have never measured mine so I don't know how hot they get, but they feel toasty.  Due to the nature of a stepper, heating will always be an issue.
> 
> Is there a reason you are not using Fusion 360 for CAM?
> 
> PZ



Yeah it does seem like a lot, but having the drivers set to 1600 (what they were by default, also what you have in your picture above) and 8000 in Mach3 resulted in really noisy movement. Everything is so much quieter and smoother now.

I just am not quite used to Fusion 360 yet, but I'll try outputting the same file from both it and Aspire and see what's going on.


----------



## phazertwo

Steppers do run smoother when you increase the steps/rev, but the loose torque as well.  I found that it wasn't an issues for me as long as I was running above 6IPM, which rarely ever happens anyway.

As with everything, there are trade offs.  Just one of the reasons I'm contemplating servos.

PZ


----------



## Caleb85

Hello, my pm940vs CNC will be coming in this week. I am a gunsmith and wanted this mill to do small “ manual” jobs and hopefully later make parts if needed. After reading this thread I am kinda nervous about everything I need to do to “ set up” the mill when it gets here. If someone if very experienced with this mill, I would love to talk on the phone about it and set up. I don’t know if one can send  private messages to each other but I will send someone my number if they would be so kind to give me some of their time. Thanks


----------



## phazertwo

To private message just mouse over the name, and then click "start conversation"


<- Name should appear about here.

The only issue I see with you trying to use the machine manually, is that the spindle is controlled with a VFD and it needs a signal from the controller in order to fire up, and change speed.  Your best bet is probably to just get it set up with Mach 3 and feed spindle commands into the controller, but there are other ways to do it if you're interested.  Also, the steppers seem cog pretty bad every 1.8° even when de-energized, which could make manual precision operations tricky.

As for setup, first thing I would do is tighten all the wire terminals you can.  It seems to be a re-accruing issues with these mills, most likely from the amount of time it spends in transit.  After that it's not to bad to get it going, especially if you have some experience with Mach 3.

Not sure how much help I can be, considering how much I have changed mine.  But I'd be willing to talk to you some night after work (I'm near Denver).

Here is a link to the mods I've made so far:
https://www.hobby-machinist.com/threads/another-pm940-cnc-vs-thread.68291/

PZ


----------



## Caleb85

Actually you might laugh but I have no experience with Mach3 , or 4.


----------



## megaplow

I did the wall mount for the electronics to mine a while back. Some of the conduit runs have been pulled apart. Do you know where I can get new conduit in longer lengths to protect my wires? I have found a few things, but they are in 100' min rolls. 

Joe


----------



## cut2cut

megaplow said:


> I did the wall mount for the electronics to mine a while back. Some of the conduit runs have been pulled apart. Do you know where I can get new conduit in longer lengths to protect my wires? I have found a few things, but they are in 100' min rolls.
> 
> Joe



I have the same issue.  I tried to find the same stuff but couldn’t.  By coincidence, just yesterday I thought to ask Precision Mathews if there is a source for the original.    
Maybe we could do a joint venture on the 100’ roll ?  There may be others .  Can you share what you found and pricing , etc ?

Cheers,  
Jake


----------



## B2

Hi Guys,  

I was just reading posts and saw yours about the conduit.  So I am a bit late, but I could use some of the conduit.   When I moved my electronics cabinet to the right hand side of the machine and rotated it so that the doors opened to the front a couple of the conduits were a little short, especially the one to the x-stepper which is on the other side of the machine.  I had to drill couple new holes in the cabinet and move some of wires around to make all of them reach where they needed to go.  I just looked again, maybe it is the same/similar as:  https://www.heyco.com/Liquid_Tight_Conduit_Fittings/?sub=flexible-pvc-conduit-tubing-fittings    The end caps look a lot like:  https://www.heyco.com/Liquid_Tight_...ittings&section=Liquid_Tight_Conduit_Fittings 

By the way, earlier in this post there was conversation about a spline wrench.  Since I live in Pittsburgh, I went to see PM.  Matt had one at the time and helped me out.   It may have been a sales sample someone gave him.   I have no info on the manufacturer other than "Made in the USA". It is nice and big/thick.   I will attach a couple of photos.  It is made of Al and with the thickness it does not bung up the splines!  I don't see it on the PM web site, but maybe Matt can get them, or can let us know where to purchase it.  I looked around on the web, but never found anything quite like this one.  I put a rule next to the wrench so you could get a perspective on its length and thickness. 

Dave


----------



## 7milesup

megaplow said:


> I did the wall mount for the electronics to mine a while back. Some of the conduit runs have been pulled apart. Do you know where I can get new conduit in longer lengths to protect my wires? I have found a few things, but they are in 100' min rolls.
> 
> Joe



If it is the stuff I am thinking of, it is available at Lowes, Home Depot and Menards in the electrical section.  Here is a link to Lowes.  Lowes Liquidtight Flexible Conduit
It is also available at McMaster.  https://www.mcmaster.com/electrical-conduit  Scroll down on the McMaster page and you will see all variations.  I am thinking they are not the cheapest but buying a few feet from them would be cheaper than a 100' roll.


----------



## B2

Thanks 7milesup.  
The "Liquid-Tight Flexible Plastic Conduit" at McMaster might actually be the same as the Heyco and is sold in smaller lengths.   However, I have looked at  the Lowes and HDepot sites and their product is way to stiff so will not make a small radius.  I have a number of lengths of something similar to these already made up with connectors.  They are stronger and more heavy duty.   I used one of them on a position where there was no motion.  However, you need the flexibility on moving tables etc.    By the way, the dimension drawings of the conduit and the fittings on Heyco maybe handy.  

Dave


----------



## B2

I was wrong.  I just went to my mill and measured the OD of the flexible tubing to be about 0.44 inch.  This is smaller than what is at Heyco or McMaster.  Their smallest OD is .57 (what they call a Trade size of 1/4) so the connectors must be different as well.  If we cannot find the same match, we will have to change the conduit, connectors, and make the holes larger in the motor electrical feed box and the main/big control electrical box.


----------



## 7milesup

I don't have your type of mill so I am shooting in the dark here but maybe the tubing you have is metric?


----------



## B2

I am sure it is metric.    PM 940M VS CNC .  My first mill ever.   However, my quick searches do not yield the flex tubing in metric ....  I left a picture of it on another Thread.     https://www.hobby-machinist.com/threads/pm-940m-cnc.76539/

Thanks for your help.  Going to have to give this a rest.  Its time to get organized for taxes!  Milling is more interesting,


----------



## megaplow

Thank you for bringing this conversation back to life. Your wrench is a thing a beauty and if you want to split a 100' roll of conduit I am in. PM me.


----------



## B2

Hi Megaplow,

I am interested, but having a lot of trouble trying to find a true replacement of what is on my machine: flexible, steel covered with plastic and small OD etc.  I have not tried calling PM yet to see if they could just get some of the conduit for us, but will wait to hear back from you.  Do you have the same conduit as I (see below)?  Is this what you want/need?  PM does seem to stock items which are not mentioned on their web site so maybe they have the conduit or can get it with their next shipment from China!

I looked at your Mill pics.  Your PM 940M VS CNC looks similar if not identical to mine pre your reworks, so it probably had the same conduits.  I, rotated by 180 degrees, and mounted my electrical cabinet on the right side of the Mill vertical post rather than the wall. The room size is small so I  put my mill stand on dolly wheels so that I can move the whole thing short distances if I want to.   I measured the OD on the conduit to the x-stepper.  While it is soft plastic I think the OD is 0.435 to 0.440" and has about per 5mm rib spacing.  This would be about 11mm OD.  However, after looking around on the web, I think this might be what is call as 12mm nominal.  Mine is steel reinforced making the inside smaller. I even looked on Aliexpress.com and Alibaba.com but did not really have any luck.  Aliexpress has lot of flexible conduit priced inexpensively,  but I do not think any of them have steel inside...just plastic tubing.   I am not for sure what the plastic is composed of, but it should be oil resistant?  I have seen multiple compositions, but the most common is PVC which is not solvent resistant but is water proof.   Alas I keep looking.  The closest looking product I have found is priced in British Pounds and is about $78 US plus tax and shipping for a 25 meter roll. Check it out:  https://uk.rs-online.com/web/p/conduit/7840094/      The good thing is that Allied is a supplier in the states so shipping would not be so much:  
	

		
			
		

		
	












	

		
			
		

		
	
  However, again this is PVC.  

Given that you are in CA and I am in PA and that shipping will probably be a significant portion of the cost, it may make more sense for each of us to purchase separately. 

Lastly, I have some extra conduit pieces of various lengths... heavy duty flexible liquid proof steel, but bends.  It is great stuff and I do not have a burning need.  If I knew what you needed maybe some of it would help you out.  I did use a piece of it to reconnect the E-stop box.  When the controls were on the back the distance from cabinet to E-stop was short.   It is about the same diameter as the conduit used on  the lamp, but is much heavier and a little more flexible.  The connectors are not metric and so I had to make a thread adapter to connect to the E-stop arm.   Anyway, if any of them would work for you it would be good.  I do not know what shipping would cost you, but after you know what you need I could see if I have a piece and if so I could weight it.  

Dave


----------



## phazertwo

My 940 cnc has the same conduit, however the ends are just regular old strain relief cord grips (cable glands) with the rubber grip part removed.  I don't see why you couldn't just remove the current wires and replace them with some SJOOW or SOOW cable (extension cord stuff rated for oil).  50' will give you a bunch left over after you re-wire the steppers.






						eBoot Plastic Waterproof Adjustable 3.5-13mm Cable Glands Joints, PG7, PG9, PG11, PG13.5, PG16, Pack of 20 - - Amazon.com
					

eBoot Plastic Waterproof Adjustable 3.5-13mm Cable Glands Joints, PG7, PG9, PG11, PG13.5, PG16, Pack of 20 - - Amazon.com



					www.amazon.com
				









						Amazon.com: Custom Cable Connection 16/4 SOOW 16 AWG 4 Conductor 600 Volt Portable Power Cable - 25 Foot Roll in a Bag: Home Audio & Theater
					

Buy Custom Cable Connection 16/4 SOOW 16 AWG 4 Conductor 600 Volt Portable Power Cable - 25 Foot Roll in a Bag: Electrical Wire - Amazon.com ✓ FREE DELIVERY possible on eligible purchases



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						Amazon.com: Custom Cable Connection 50 Foot - SJOOW 16 AWG 4 Conductor 300V Portable Power Cable - 50 Foot Roll in a Bag: Home Improvement
					

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FYI the difference between SJOOW and SOOW is the voltage rating.  SJOOW is 300v and SOOW is 600v, so SOOW has much thicker insulation making the overall diameter of the wire much larger.

PZ


----------



## B2

Hi PZ,

Thanks.  Another wire option is good! I kind of like the look of the flexible conduit and have managed to stay with the original size on my 940M up until now.   If possible I would prefer not to have to resize the holes in the connector boxes or have a kludge connector.   Anyway, my problem is not too severe, the x-axis cable is just a bit short and so as you can see the cable at the connector broke when I ran the x-axis near the the full swing.  

I have been reading some of your other posts and enjoying them and the photos.  I was following your belt drive and the Acorn conversions. Thanks.  

If you do not mine I have a couple of questions about your other posts?  If it is too much, please just say so.  

1) I am still running the nMotion/Mach3 and it does not seem to be all that bad so maybe I will hold off on the Acorn upgrade for a while.  When my machine came with the initial nMotion setup code it had the three axis max velocities set  to x, y, z = 50, 40, 20 in/min and 8000 steps per (inch).   I think in one post that you talked about the maximum velocities you could get out of your machine.  I know mine will go a lot higher, but how did you determine the limit? Was it determined at the velocity where motor steps were missed and and so might not return to the same location.    If so is this not highly dependent upon the load?  (I had assumed that was why the factory set it up at 50, 40, 20.  The y stage is stacked under the x stage so it must accelerate and move more mass.  y has to move all of the mass of x stage plus its own mass and friction.  The z axis head is just very heavy so it is not simply the inertia that has to be accounted for, but gravity.  I did a poor man's weight measurement of the z axis stage etc and got over 250 #s.   )

2)  I recently made a bunch of x-y plane 8-9" radius cuts over ~180 degrees and it all worked very well and repeatable, but the machine was kind of noisy when both x and y are swinging.  I was running at about 30in/min.  I was cutting plywood for a "honey do" project so the cutting speed was not a big issue.   While I find the limited documentation to be troubling, I have had few problems with nMotion.  Maybe I am just not experienced enough, but if my machine is running "OK", what do I gain by changing over to Acorn.  Is the motion a lot smoother?  Maybe the software is just easier to use?

3) In your spindle motor and belt drive conversion....  maybe you want to post the answer on that forum rather than here.  I could not find where you mentioned the details/models of your motor and driver.    Could you do so?  (Maybe just a picture of the motor and driver labels.)   Also could you post your Fusion 360 code that your wrote when you drew up the nice schematic of the 940 spindle head?   Having this could be handy.   

4) In the photo it looks like with your new DC spindle servo motor will have the encoder on the motor, not the spindle.  Do you think with the belt drive you would be able to do rigid tapping?  Does the Hobby version of Acorn and software provide for rigid tapping?  G84? It does not seem that Mach3 provides for G84 since in the documentation the description of G84 is a faded font.  Likewise, at Centroid, the comparison page of controller boards mentions rigid tapping for the more expensive boards, but not for Acorn.  Anyway, I suppose if a mill had the mechanical capability of accurate spindle speed and phase control and can reverse without excessive back lash, which your might after the conversion, then you might be able to write G-code to mimic G84.    I was thinking about trying to build an auxiliary stepper hanging off the side of the head assembly directly driving the spline via tooth belt drive.  The idea would be to disengage the normal spindle gears by turning the gear/speed select nob midway between speed 1 and 2 and then driving the spline via the stepper.  I thought I might be able to use the 4th axis motor and driver for this drive.    I suppose one could just replace the current 3phase drive motor with a servo system, but the current head gears have about 1.25 +-.25 degree back-lash at the spindle.  

Thanks.  

Dave


----------



## phazertwo

I defiantly don't mind responding with my $0.02.

1.) I locked a part in the vice that was about as large as I figured I would ever machine and then created a program in Fusion 360 that mimicked moves I figured I would make (LOTS of adaptive).  Then I ran it, adjusted velocity, and accel.  I repeated this several times until I got it locked down with no missing steps.  I got some very low numbers with the nMotion, but with the Acorn I'm at 100ipm in the x and y, and 65ipm in the z.  One thing that GREATLY contributes to stepper noise and missed steps is "smoothing" always use it in Fusion adaptive processes.  Even truing it to 0.0005" makes  a HUGE difference.  Acorn also has smoothing built in, once I turned that on, things got even better.  After all of this was said and done, and I ran a few parts I realized that missing steps is more often than not related to bad programming.  Asking the controller to process 200 lines of G code to go around a 0.5" radius makes no sense.  The "noise" comes from the stepper constantly changing speed going though an arc.. and adaptive moves will do it all the time, so be careful.

2.) I kinda answered this with #1, but SMOOTHING!  Turn smoothing on and run the same path again and see what it does.  What you gain by going to the Acorn is mostly piece of mind, but there are also things like built in smoothing, great documentation, and their only tech support (fourm) is great.  The nMotion/M3 can get the job done, but it's not the quality I was looking for.  When I realized the estop circuit was a normally open circuit, that was kinda the icing on the cake for me.  I take safety very seriously and a normally open estop circuit is a HUGE no, no.  If they cut that very simple corner, where else did they cut corners?  Like I said, nMotion and M3 will get it done, but I like piece of mind.  Centroid has been doing aftermarket CNC control for a long time, and they are right here in the US of A.

3.) I didn't post motor specs because the motor really isn't feasible as a hobby grade spindle motor... even used units on ebay go for about $2k+ for a motor/drive.  I pulled them out of a machine in a scrap pile... so they were essentially free to me.  It's a 1.5kw Lenze AC servo, 7k RPM motor.  Anyone in industry will tell you that Lenze/AC Tech is a big hitter in the motor control world (I rank them above Allen Bradly for quality).  I think most hobby guys would be looking at a DMM level servo motor for a hobby application, and no doubt they would work too.

4.) Most, if not all, servo motors have the encoder built in these days.  I cannot use this for feedback to the Acorn even if I wanted to, there just isn't a provision for it in the drive.  Past that, I would ONLY use a 1:1 encoder for rigid tapping, just too much at risk to try anything else.  Also, the Acorn is capable of ridged tapping, cut2cut has his setup for it and he is simply using a nice 1.5hp motor and high quality VFD.  I believe you have to have the Pro level software, but I'm not sure.  He does have an encoder attached to his spindle to accomplish it, and as far as I know it works great.

Your idea about a 4th axis driving the spindle would likely work if you could figure out how to program it... but for the cost of an encoder, not worth it IMO.

I'll also include the negatives to the Acorn.

It's more expensive
Software can get expensive if you want full probing cycles
It's only 4 axis capable
Limited I/O
You have to have the Pro version of the software to run the MPG
MPG is expensive compared to others (but it's very nice, and wireless!)

Hope this all helps!  If you have more question, feel free to ask them in my build thread.

PZ


----------



## B2

Hi PZ,
Thank you for the extensive answers.  I am sure I will have more question as I progress.

I have the standard $175 Mach3 version that was available Dec 2017, Version R3.043.066   I miss-understood the PM940M literature at the time of purchase and thought that the nmotion only had a parallel port interface so while waiting for the arrival of the Mill from China I looked around for an old PC that would still have a parallel port.  I found a pretty good machine on Craigslist, Gateway with Intel quad processor running at 2.6GHz and 4GB RAM.   I replaced the Vista OS with 32 bit Win7 Enterprise so it only accesses 3GB of the memory.   From my perspective, another disadvantage of the Acorn is that it requires Win10.   I have a number of expensive software programs that do not run on Win10 so I have all of my other machines running on Win7....    

So tonight, I mounted a dial gauge in my 100lb vise (photo) and tested the x-axis motion... to try out a simpler version of your speed test.  My 940M came with a memory stick with a Mach3 profile already programed: the x-axis set to a max velocity of 50in/sec and an acceleration of 20in/sec-sec.    I wrote some code that basically moved the x-axis off the gauge by an inch then ran the x-stage back and forth 3 ins. several times at a test velocity and acceleration and then returned the spindle back to the dial gauge to see if the setting had change.  I figured that 3 inch of travel would always be more than enough to ensure that the motion had always reached the coasting velocity.   I put in a 0.5 sec. pause at the end of each movement just so I would have time to shut the process down should something go really badly.   At the end of the motion the stage moved back to the zero position and stopped so I could measure any error due to missing steps.  I could not see any change on the dial gauge reading, that is, it it returned to the zero each time.  Here was about 0.003 backlash so I the code  with the motion always approaching the gauge from the same direction to avoid this.  (The backlash is a screw and bearing problem and not a stepper or Mach3 problem and can be compensated for.)  I took the velocity up to 150in/min and acceleration up to 40in/sec-sec.  I ran this, and other slower speeds several times and never saw any positioning error, except one time when it may have been operator error and the stepper just spun and the table never moved at all!  I am not for sure what that was about and I could not repeat it?  The vise and dial gauge was the table load.  I did not turn on the spindle as I wanted to wanted to always touch to the same point on an end mill.  What I did observe in all of this and I hope to correct was that at the highest velocity and de-acceleration to a stop, 40 in./sec-sec the entire mill would rock just a bit.... an unwanted vibration.   I am guessing one of my stand corners is not sitting on the floor with the same pressure as the other three corners.  It could also simply be that the 200 lb. electronics control box, which is hanging on the side of my vertical post, causes the mill to wobble.  I should probably put a post under it and take a bit of the weight off of the lathe vertical.  I do not really see any reason to have such a high acceleration setting as it represents a small portion of the time of each movement.    I did not try to go any faster as I was called away.  

I tend to think that if there is going to be missing steps they are most likely to occur during the acceleration/de-acceleration as this is when the stepper is working the hardest. Once at speed the stepper just has to over come stage friction and force to drive a cutter into the material.  

When I find a little more time I will test the y-axis and then maybe  the z-axis.  Then I can move on to test more complicated motions where at least two axis are driven at the same time. I do not expect to do very well on the z-axis as I have not removed the crank/worm gear to screw drive and it makes considerable noise at is flops back and forth.  ( I hate to give up this manual vertical means.)  However, I expect that vibration or jerking of many forms on the mill will translate to jerking the stepper motors and might cause a micro-step error if the velocity/acceleration settings are near the limit of performance.



I do agree with you about the estop and safety. It is a serious issue.   I will take the cover all of my switch box and measure the switch to see if it is normally open or closed.  The drawings show it as being unsafe, but then why should I believe the drawing.  Maybe they updated the design since your machine was built.  For safe operation, if an estop wire comes loose at the stop should be activated.  If mine is not that way, I may look to see if there is a fix for this.


----------



## phazertwo

When the stepper "spun but the table never moved at all" you where missing steps.  In my experience a stepper won't miss just one step or micro step, it misses all the steps until the speed becomes low enough that it can actually get going again.  Remember, if the motor misses a step, that means it basically stopped for an instant, but the controller is still driving it at what ever speed it was at when it missed the step, which means you essentially have unlimited acceleration.  Think about it like this, you're on a train that is moving, and you fall off, you're not going to be able to get back on that train until it slows to the point you can catch it.  So that sound you heard was the stepper trying to rotate, but not actually rotating (missing steps).

Hope this makes sense.

PZ


----------



## Sal_the_man

Hello all!

I am taking over for @chocadile troubleshooting and will try to get our CNC running.

He mentioned that we have an issue with our axes running past the limit switches...

Well I'm unable to get the motors running at the moment LOL.

Below I've attached pictures of our set-up and of the mach3 software settings that are mostly copied after @cut2cut 's pictures.

Powered on the nMotion CNC Controller via the software which finally had the limit switches registering under the diagnostic page once I pushed down on the plungers. But still unable to get the motors moving.

I figure I have the wrong port specified?

Any input would be greatly appreciated!

Thanks,

Salman

Edit: I am an idiot and forgot to power the motors LOL. Ok all three motors are working. Now the Z-axis and X-axis are not homing correctly. Y-axis is fine. @chocadile last stated


















































































^That is with me pushing down on the Z-axis limit switch plungers.


----------



## phazertwo

All of the wires in my limit switches were loose, and a few of them were pulled out of their terminals.  I'd start there.

PZ


----------



## Sal_the_man

@phazertwo thanks for the tip, but I already solved the issue!

The pins specified in my software did not align with the physical wiring. The X & Z pins were mixed.

Everything is now homing and zero-ing as it should be.

Took a whole day of following wiring, checking voltages, and the whole nine-yards before realizing the error lol

The correct settings and wiring diagram displayed below


----------



## B2

phazertwo said:


> When the stepper "spun but the table never moved at all" you where missing steps.  In my experience a stepper won't miss just one step or micro step, it misses all the steps until the speed becomes low enough that it can actually get going again.  Remember, if the motor misses a step, that means it basically stopped for an instant, but the controller is still driving it at what ever speed it was at when it missed the step, which means you essentially have unlimited acceleration.  Think about it like this, you're on a train that is moving, and you fall off, you're not going to be able to get back on that train until it slows to the point you can catch it.  So that sound you heard was the stepper trying to rotate, but not actually rotating (missing steps).
> 
> Hope this makes sense.
> 
> PZ



Hi PZ,

I understood that the sound was of the stepper missing all the steps, I was confounded as to what velocity and acceleration I must have inserted in the the motor tuning to cause it.  I was incrementally increasing the Vec and Accel to see when I would start missing steps and then suddenly I must have gone way overboard on the settings (operator error).  Maybe I typed in the Accel at a value significantly higher than 40in/sec-sec.  That would do it for sure, but I should have caught this.  Anyway, when this happened I set the Accel back to the factory setting of 20in/sec-sec. and started my measurements over.  

Forgive me for writting the stuff below.  I just wanted to work through it for my own thought processes.  

Some simple math.  For a given acceleration setting, I want to determine the travel distance before reaching the terminal velocity (V1, velocity as set in the motor tuning configuration page) is reached.  Assume: X=distance, Xo=initial starting location (Xo=0), V=velocity as a function of time (initial velocity is zero), A= the acceleration (constant value as set in the motor tuning), t = time, at time t1, the terminal velocity, V1, is reached.  So the position during acceleration is described by X-Xo=0.5A_t^2.  The instantaneous velocity during the acceleration period (time 0 until t1) is simply V(t)=dx/dt=A_t.  So t1 can be obtained by solving for where V(t1)= V1.  So t1=V1/A.  (simple) So the distance traveled to reach terminal velocity is X(t1)-Xo= .5A_t1^2.  Now lets assume the motor tuning values of V1 to be 120 in/minute and A to be 40 in/sec-sec.  Use 60 second in a minute.    Then t1=V1/A=(120/60)/40 =2/40 = 0.05 seconds. This then corresponds to a distance of X(t1)-Xo= .5A_t1^2=.5_40_0.05^2=0.05 inch.    In other words, the stage only has to travel 0.050 inches before reaching the terminal velocity and so get out of the acceleration process.  From a visual perspective, the acceleration to the terminal velocity is essentially instantaneous and difficult to distinguish for moves of any common length!

So my motor tuning logic is:  Keep the acceleration value low so that steps are not lost during the period when the motor has to exert the most force to over come the inertia of the mass of the stage+vise+work piece.   (During the constant velocity portion of a x or y move, in concept, the motor only has to over come the friction of the stage.  During the constant velocity of the z stage it must over come both the friction and the gravitational weight.) In the motor tuning set up that I recieved from the factory, the x,y,z acceleration values were all set the same at 20in/sec-sec while the terminal, x, y, z, velocities were set at 40, 30, and 20, respectively.  

By the way, a "g" is 9.8meter/sec-sec or 385.8 in/sec-sec, so when Mach shows 40in/sec-sec for the acceleration this corresponds to 0.103 g's , so is only 10% of the g from gravity for moves in the z direction!  Clearly the 940M can lift the z stage's 250 #s of weight.  So the z-axis stepper, which is a little larger than the x and y steppers,  can carry a force associated with more than 1 g.   So most of the above discussion seems almost irrelevant.   
However, there is another part of physical mechanics which is less talked about in the physics text books.  Rather than just dynamic friction it is static friction, sometimes called stiction and the extension of this being stick-slip-stick-slip... process.  When an object sits for a while on a surface it tends to stick to it due to molecular bonding.  This would especially be true for the x and y stages where with the full weight of the stages setting stationary the weight would tend to spread the oil out or push it out totally yielding a bond between the stage and the ways.  Breaking this loose initially can take much more force than just discussed.  However, this would be another reason to set the tuning acceleration to a lower value... give the stepper a little more time to break the stiction and get the stage up to speed.  I suspect that this is less critical on the z-axis due to the weight of the head tilting the contact (wedge) at the ways.  The bottom corners of the ways will have a lot of pressure between the parts while the top will have little to nothing. 

Dave


----------



## B2

Hi Sal_the_man,

Glad to hear you got the machine working.  I guess I was lucky. Mine worked right out of the crate, but I did have some fixes to make.

If you do not mind could you post a picture of the outside of your electronics control box showing the wiring connectors to the nMotion ... the outside of the cabinet, where they come through.  I posted an image of the inside of my machine and it is quite different from yours as to the location of the nmotion box and its attachment to the cabinet.  Mine is on the other side and the nMotion is not touching the side of the metal cabinet, but is fully inside.   Also, my logic power supply is next to the nMotion box not in the row above. 









						PM-940M-CNC
					

Got on one the last 940M-CNC's that PM produced.  Its an all options unit with the 4th Axis, VFD, and auto oiler.  Unit also came with a small coolant reservoir, pendant, and R8 drill chuck and shell mill,  woohoo.  Used a friends bobcat with forks to move the large crates off the semi trailer...




					www.hobby-machinist.com
				












						PM-940M-CNC
					

Got on one the last 940M-CNC's that PM produced.  Its an all options unit with the 4th Axis, VFD, and auto oiler.  Unit also came with a small coolant reservoir, pendant, and R8 drill chuck and shell mill,  woohoo.  Used a friends bobcat with forks to move the large crates off the semi trailer...




					www.hobby-machinist.com
				




If it would be of any help to you I could provide you with the factory Mach3 profile that came with my machine.   You probably do not need it any more, but you might want to compare yours to mine?


----------



## Sal_the_man

@B2 I'd really appreciate it if you could share your Mach3 profile!

We're going to have our first crack at machining today. So if it doesn't work I can have your settings to work with.

I'll take a picture of the outside panel shortly


----------



## Sal_the_man

@B2 

*Side panel conduit. Top one goes to control box. Bottom one runs to motor and chuck on the floor (don't know why it's there, just started working on this thing yesterday).*






*Large conduit running from the control box*






*Computer connections, going straight into the CNC control box*






*Top of the panel. Middle line of conduit runs to the Z-axis motor*






*Top-left conduit runs to Z-axis limit switch*






*Bottom of panel conduit. The four right lines include the wiring for the X & Y-axis limit switches and motors. The far left line is for the oil pump motor.*






*Our beloved CNC controller that is claimed to be a POS by the internet*






*The wiring here is for the limit switches*






*This panel carrying spade connectors is at least for limit switches from what I traced*






*These wires connect to their respective motor drivers. All wrapped in conduit that snakes around inside the panel*






*Not sure what these wires are for, but I have the wiring diagram *


----------



## B2

Hi Hi Sal_the_man, 

Great set of pictures of the wiring.  Thanks.  My 940M is very similar, but as I noted the layout of the nMotion is different.   Your nMotion mount with the Pendant cable connector firmly screwed to the cabinet is an improvement over mine.  It is not clear how your USB cable enters the cabinet, but I assume that there is a mechanical holder for it as well.   Of course I had punch and drill some new holes in my cabinet for the reoriented wires and to move all of my wire feeds around when I mounted the box on the right side of my vertical post.  With the cabinet rotation the doors  now face toward the front and I can push the mill closer to the back wall.  I also mounted my light on the left side of the post.  The doors now have a clearance problem with the big vertical limit switches, but this is something I can fix with time. 

I will attach the .XML file and the .dll file that came with my Mill from the factory on a USB jump drive.   However, the forum will not allow me to attach a file with a .xlm or .dll extension.   So I will change the extensions to .doc and you can change it back after you down load it.  Of course if you try to open the .dll file with Word or a text editior does not work as it is a bin file.  This is the first time I have tried to upload any file other than an image so well will see.

There was also a minor set of instructions for their installation.   
"
Pls copy file "nMotion.dll" to  "Mach3\PlugIns" after mach3 software installed.
And the "mach3mill.xml" is the configuration  file of mach3 sofeware you can copy it  to "mach3\" (the mach3 install directory). 
"
As you work on your machine please see if your mechanical E-Stop is wired Normally Open (NO) or Normally Closed (NC).  The mine is, and PZ's (Phazertwo) was wired NO.  Hence throwing the E-stop switch takes the input, Pin 16 to to ground  to activate the stop.  This is not good (not safe) since the wires from the switch to the ground or the sense wire to pin 16 could come loose or break and E-stop would not function.  The proper way to do this would be that that the nMotion require the swich be NC for the machine to run.  That way a wire break would shut the machine down.  Anyway, in the Mach3 settings there is a place where one can choose E-stop logic active low so maybe unchecking this box will call for an active high signal.  What not clear is if the nMotion would work with this reversal setting!


----------



## phazertwo

B2 said:


> Hi PZ,
> 
> I understood that the sound was of the stepper missing all the steps, I was confounded as to what velocity and acceleration I must have inserted in the the motor tuning to cause it.  I was incrementally increasing the Vec and Accel to see when I would start missing steps and then suddenly I must have gone way overboard on the settings (operator error).  Maybe I typed in the Accel at a value significantly higher than 40in/sec-sec.  That would do it for sure, but I should have caught this.  Anyway, when this happened I set the Accel back to the factory setting of 20in/sec-sec. and started my measurements over.
> 
> Forgive me for writting the stuff below.  I just wanted to work through it for my own thought processes.
> 
> Some simple math.  For a given acceleration setting, I want to determine the travel distance before reaching the terminal velocity (V1, velocity as set in the motor tuning configuration page) is reached.  Assume: X=distance, Xo=initial starting location (Xo=0), V=velocity as a function of time (initial velocity is zero), A= the acceleration (constant value as set in the motor tuning), t = time, at time t1, the terminal velocity, V1, is reached.  So the position during acceleration is described by X-Xo=0.5A_t^2.  The instantaneous velocity during the acceleration period (time 0 until t1) is simply V(t)=dx/dt=A_t.  So t1 can be obtained by solving for where V(t1)= V1.  So t1=V1/A.  (simple) So the distance traveled to reach terminal velocity is X(t1)-Xo= .5A_t1^2.  Now lets assume the motor tuning values of V1 to be 120 in/minute and A to be 40 in/sec-sec.  Use 60 second in a minute.    Then t1=V1/A=(120/60)/40 =2/40 = 0.05 seconds. This then corresponds to a distance of X(t1)-Xo= .5A_t1^2=.5_40_0.05^2=0.05 inch.    In other words, the stage only has to travel 0.050 inches before reaching the terminal velocity and so get out of the acceleration process.  From a visual perspective, the acceleration to the terminal velocity is essentially instantaneous and difficult to distinguish for moves of any common length!
> 
> So my motor tuning logic is:  Keep the acceleration value low so that steps are not lost during the period when the motor has to exert the most force to over come the inertia of the mass of the stage+vise+work piece.   (During the constant velocity portion of a x or y move, in concept, the motor only has to over come the friction of the stage.  During the constant velocity of the z stage it must over come both the friction and the gravitational weight.) In the motor tuning set up that I recieved from the factory, the x,y,z acceleration values were all set the same at 20in/sec-sec while the terminal, x, y, z, velocities were set at 40, 30, and 20, respectively.
> 
> By the way, a "g" is 9.8meter/sec-sec or 385.8 in/sec-sec, so when Mach shows 40in/sec-sec for the acceleration this corresponds to 0.103 g's , so is only 10% of the g from gravity for moves in the z direction!  Clearly the 940M can lift the z stage's 250 #s of weight.  So the z-axis stepper, which is a little larger than the x and y steppers,  can carry a force associated with more than 1 g.   So most of the above discussion seems almost irrelevant.
> However, there is another part of physical mechanics which is less talked about in the physics text books.  Rather than just dynamic friction it is static friction, sometimes called stiction and the extension of this being stick-slip-stick-slip... process.  When an object sits for a while on a surface it tends to stick to it due to molecular bonding.  This would especially be true for the x and y stages where with the full weight of the stages setting stationary the weight would tend to spread the oil out or push it out totally yielding a bond between the stage and the ways.  Breaking this loose initially can take much more force than just discussed.  However, this would be another reason to set the tuning acceleration to a lower value... give the stepper a little more time to break the stiction and get the stage up to speed.  I suspect that this is less critical on the z-axis due to the weight of the head tilting the contact (wedge) at the ways.  The bottom corners of the ways will have a lot of pressure between the parts while the top will have little to nothing.
> 
> Dave




You are forgiven, don't worry, I nerd out on this stuff too .  If (I don't have time to double check your math) your table does really take 0.050" to get up to Vmax, that's not really instantaneous.  If you make some adaptive tool paths in Fusion, then simulate it and turn on all the dots that represent lines of code, you can see that often times lines of code are "closer" that 0.05" in the tool path.  This is where problems show up.

The static friction bit defiantly makes sense (I refer to this as stiction).

As for the Z axis and gravity, your missing a step there, which would be force.  Nothing changes velocity with out a force acting on it.  The stepper is not generating acceleration, it's generating force and force is F=mA.  So it;s generating enough force to cause an acceleration of 0.103g's in the opposite direction as gravity. 

You said your head weighs 250lbs, which is 113kg.  So F = 113kg x (9.8m/s^2*.103) = 114N of force.  Or ~25lbs.  So we know that the net force on the head is +25lbs (+for up direction), but we also know there is the force from gravity, which is -250lbs (negative for down direction).  That means that the stepper is providing 250lbs to over come gravity + 25lbs to provide the acceleration.  When you sum the forces, you get 275lbs, so we know the stepper is generating at least that much force, but we know is more than that because we didn't take into account stiction, or friction.

Hopefully that all makes sense.... 

PZ


----------



## Sal_the_man

B2 said:


> Hi Hi Sal_the_man,
> 
> Great set of pictures of the wiring.  Thanks.  My 940M is very similar, but as I noted the layout of the nMotion is different.   Your nMotion mount with the Pendant cable connector firmly screwed to the cabinet is an improvement over mine.  It is not clear how your USB cable enters the cabinet, but I assume that there is a mechanical holder for it as well.   Of course I had punch and drill some new holes in my cabinet for the reoriented wires and to move all of my wire feeds around when I mounted the box on the right side of my vertical post.  With the cabinet rotation the doors  now face toward the front and I can push the mill closer to the back wall.  I also mounted my light on the left side of the post.  The doors now have a clearance problem with the big vertical limit switches, but this is something I can fix with time.
> 
> I will attach the .XML file and the .dll file that came with my Mill from the factory on a USB jump drive.   However, the forum will not allow me to attach a file with a .xlm or .dll extension.   So I will change the extensions to .doc and you can change it back after you down load it.  Of course if you try to open the .dll file with Word or a text editior does not work as it is a bin file.  This is the first time I have tried to upload any file other than an image so well will see.
> 
> There was also a minor set of instructions for their installation.
> "
> Pls copy file "nMotion.dll" to  "Mach3\PlugIns" after mach3 software installed.
> And the "mach3mill.xml" is the configuration  file of mach3 sofeware you can copy it  to "mach3\" (the mach3 install directory).
> "
> As you work on your machine please see if your mechanical E-Stop is wired Normally Open (NO) or Normally Closed (NC).  The mine is, and PZ's (Phazertwo) was wired NO.  Hence throwing the E-stop switch takes the input, Pin 16 to to ground  to activate the stop.  This is not good (not safe) since the wires from the switch to the ground or the sense wire to pin 16 could come loose or break and E-stop would not function.  The proper way to do this would be that that the nMotion require the swich be NC for the machine to run.  That way a wire break would shut the machine down.  Anyway, in the Mach3 settings there is a place where one can choose E-stop logic active low so maybe unchecking this box will call for an active high signal.  What not clear is if the nMotion would work with this reversal setting!



My bad, below is how our wires go into the CNC controller. It's quite convenient.

What design software, CAM software, and Post Processor are you using?

At the moment we're using Autodesk Inventor and HSM


----------



## B2

Thanks for the photo.  It is a much better physical connection than the way mine was shipped.  

Was my Mach3 Profile of any use?  I noticed in your pictures that you have the 4th axis hard ware installed, but in your photo, 299793, of the ports and pins configuration window that the A axis was not enabled.  

CAD-CAM software:  I use WIN7 64 bit.  

From the forum it appears that a lot folks are using Fusion 360 (AutoDesk/AutoCad).  It apparently is free for an individual, non-commercial.   There are some youtube tutorials and I watched the two first intro ones.   



    It seemed pretty friendly and powerful.   However, I have yet to try it, as the C drive of my 1TB laptop HHD, where I design most of the time, is totally full.   At the University, where I use to teach and do research before retiring, everyone seemed to be using Solildworks.   But, I never tried it.  From what I could tell, they did not have a free or cheap version for the hobby folks.  So it is way too expensive for my limited use... and it is on an annual maintenance lic arrangement so you have to pay thousands over and over if you want to keep it up to date.  At some Universities it is free for students.  

However, there is another software that I sometimes use that is pretty powerful.  FreeCAD.  It is supported by users (like linux) and so it free.  It seems to do everything, but it took me a bit to learn to use it.  It is used for a lot of different kinds of design, not just mechanical CAD.  It also has a tool path builder, tool path visualizer and there are several pug-ins for converting to G-code.   There is no plug-in specifically written for the PM-940M, but I tried a couple of different plug-ins to convert to the G-code and they all seemed to work as my code had not exotic commands, but I was doing 2.5 dimensions, arcs, drilling and etc.   It is written in Python.  You do not really need to know Python to use FreeCAD, but the plug-ins for the G-code conversion are written in Python and if you want to modify one of them you might need to learn some Python.  If you want to try your hand at Python (another user group supported software -- free) I suggest that you download and install  Anaconda Navigator.  It is a shell for several types of Python applications and it will install everything you need without trying to install the individual parts of Python.   In side Anaconda Navigator,  I commonly use the Spyder Application, which has lots of science software built it.  Python Spyder probably has all of the functionality of MatLab, if you know it, but is not as user friendly.  I have used MatLab a lot, but it is priced like Solidworks!

Since FreeCAD is also written in Python it uses a lot of the same utilities as loaded up in Python.  For a clean installation of both, I suggest that you first in stall Anaconda (click install everything).   This worked great for me.  Then install FreeCAD and when given the choice, during the install, link the path to Python.   You can install FreeCAD alone, but doing so is not as efficient if you later want to install Anaconda/Python. 

One other option, especially, is to simply use the Wizards if they are already built into Mach3. I think I purchased them all, but some built into mine and there are others keep telling me I am missing the lic.  (I may have put the lic in the wrong folder so something as I did purchase it.)  Anyway, these are great teaching tools.  When you access them they jump to another window and you select what you want..... i.e. drill holes in a circular pattern, make arcs or circles, mill down a surface, cut a spline, cut threads on a post or in a hole, etc.   There is even a more man's version of engraving of letters.  They create and load the G-code when you jump back to Mach3.  There you can copy or edit the G-code and save it. Or, if you buy the the stand alone Wizards (a different $50 package) then it runs with its own shell totally outside of Mach3. It has mostly, but not quite, the same functions in it as what is in my Mach3 package.  But it has more flexibility in its shell.  You can design from one of the apps then another app and then another and also write lines of G-code in between each without leaving the Wizzard App.  When you save it you have g-code for all of it.  

I find for many simple applications I can just use the Wizzards, modify the results a little and I am up and running without ever opening my big CAD package.   

Dave


----------



## Sal_the_man

@B2 , Dave thanks for that excellent post!

I downloaded your files but the microsoft word file conversion yields the file having odd looking shapes for text. I do have them saved though in case our settings do not pan out for us.

@chocadile and I are downloading Anaconda and FreeCAD since the gcode from HSM, the Autodesk CAM, is giving us a "bad character" error on Mach3

I wish I could write as well as you or provide enough information. But we're still working towards our first cut!


----------



## B2

Hi Sal_the_man & Phazertwo,

Re: E-Stop connection fix

I though you both might like to know I ran a quick experiment this morning.    I went into the configuration files ports and pins and found the E-stop setting.  It is set up to active on a "low" signal to pin 16.  However, if you simply uncheck this "low" box so that it is effectively active on a "high" signal lever then the logic reverses.   That is the mill will only run if the  This means that I only have to purchase a normally open switch and then the mill will only run when input to pin 16 is grounded.   Amazon seems to have a number of sellers of these cheap switches for around $5-$7, which have both NC and NO built in.  22mm is the hole size.   I suspect that all of the nMotion Inputs (limit switches etc) like this pin, but if there connection fails it is not nearly as serious an issue.   These Amazon cheap plastic E switches look very must like what is built into our mills.  Or one can go to an electronics supply house and spend $40 on perhaps a more rugged version.  

Dave


----------



## Sal_the_man

B2 said:


> Hi Sal_the_man & Phazertwo,
> 
> Re: E-Stop connection fix
> 
> I though you both might like to know I ran a quick experiment this morning.    I went into the configuration files ports and pins and found the E-stop setting.  It is set up to active on a "low" signal to pin 16.  However, if you simply uncheck this "low" box so that it is effectively active on a "high" signal lever then the logic reverses.   That is the mill will only run if the  This means that I only have to purchase a normally open switch and then the mill will only run when input to pin 16 is grounded.   Amazon seems to have a number of sellers of these cheap switches for around $5-$7, which have both NC and NO built in.  22mm is the hole size.   I suspect that all of the nMotion Inputs (limit switches etc) like this pin, but if there connection fails it is not nearly as serious an issue.   These Amazon cheap plastic E switches look very must like what is built into our mills.  Or one can go to an electronics supply house and spend $40 on perhaps a more rugged version.
> 
> Dave



Good call. I'll play with those settings as well, our e-stop button does NOT work as is - can only stop via Mach3. 

Those switches are quite cheap too.


----------



## phazertwo

I totally forgot that the real reason I trashed the nMotion was because of the delay between e-stop activation and actual stop of motion... I think it was like 3 seconds on mine, which was enough to mess up a vise jaw and a few end mills.  Not to mention in a safety situation, you want that thing shut down before your hand is off the button.

PZ


----------



## Sal_the_man

phazertwo said:


> I totally forgot that the real reason I trashed the nMotion was because of the delay between e-stop activation and actual stop of motion... I think it was like 3 seconds on mine, which was enough to mess up a vise jaw and a few end mills.  Not to mention in a safety situation, you want that thing shut down before your hand is off the button.
> 
> PZ



Wow that's dangerous, shouldn't even have been sold with that performance...well then


----------



## B2

Hi Sal,

Sorry any confusion.  The Forum would not let me seen the files with their correct extensions.  The files have dummy .doc extension on them just to get them past the Forum attach file processor.  They are not word documents at all.  Just change the file name extension back to .xml or .dll   (The file names should read: Mach3Mill-factory PM940M_CNC.xml and nMotion.dll ) for the Mach3 profile and the system nMotion file.  Don't leave them as .doc  Then install them per the quoted text in my message directly into the Mach3 program and run it.  Then you can view the Mach3 configuration pages etc.  

If you have the wizard that is built in to Mach3 use one of them for your first cuts code.  (The important thing is to get started, not to make anything worthwhile.)   Then you will get the G-code concept by studying what is generated. I have no idea of your back ground.  There are various short pieces of code in the Mach3 manual in the chapter of the descriptions of the G code.    While I had never written G-code when I purchase my mill, I have history in various other software languages.  Even then it took me bit to get started because I had also never run a mill at all!  

Dave

PS.  It will take a little while to learn the FreeCAD, but there are lots of online tutorials for it and the Anaconda software.  Powerful stuff, but you have to wade in and be patient.

Another small piece, of very nice free, software is notepad++ .  It is what a lot of software programing  folks use to draft their software. I commonly use it when drafting G-code etc.  It has very powerful search and replace features.    It is sort of like a much more powerful Windows notepad program and allows you to open multiple files at the same time, tabs, and so you can copy and paste from one file (tab) to another with a few strokes.     It is small and will install easy and it does not forget what you might have had open when you shut it down.  With this you can try to open the .xml file or any other file.  You can then see the characters, but they may not make a lot of sense, especially if it is a HEX file, like the .dll file.  However, if you open the .xml file with notepad++  program you will see a long string of characters with no line returns.  I just downloaded it, changed the extension back to .xml and then openned it with notepad++ and the results look like:

<profile><Preferences><PulseSpeed>0</PulseSpeed><Profile>Mach3Mill</Profile><Layout>1024CN.set</Layout><FirstRun>1</FirstRun><U......

and just goes on and on.   No line returns.   There is probably some  Mach3 or other editor that is made just for this file.  Anyway, the Mach3 software would read each of the  <> segments and interpret them according to its code.  

Dave


----------



## B2

Hi PZ,

Interesting.  There is absolutely no observable delay between when I hit the e-stop and the machine stopping!  Who knows?  Your nMotion may have had an entirely different set of firm ware from mine?   Even when I changed the setting to active high there was no response delay.  But 3 seconds is a long long time in the world of digital electronics.  One would actually have to write special code to built is a 3 second delay.  It sounds like there was large capacitor that had to be charged or discharged through a high resistance or very poor connection.   Anyway, I do not really think the unsafe part of the E-stop hook up is the nMotion or Mach3 folks issue.  It appears the issue is in the way the PM machine is wired and it does not seem to be a difficult fix!

Dave


----------



## phazertwo

If I remember right there was a buffer time setting in Mach 3 somewhere, probably under the configuration menu for the nMotion.  I could turn that time way down to fix the estop problem, but then I would have other issues, like missing steps.  It was kinda a balancing act until I said screw it and went Acorn.  It defiantly was not a a hardware level issue like you described above w/ the capacitor, simply because I could change the estop timing with the change of that buffer value.

I wonder if it was due to the quality of computer I was running?  I built a way better one for the Acorn, so that could have been the issue.  And I agree completely, the NO vs NC estop is not the nMotion or M3's issue, it a PM issue.  It's easy enough to flip an input from NO to NC in M3, and the nMotion doesn't care what it is, it just tells M3 if it's off or on.

FYI this is the switch I used when I went NC, it has an NC and NO terminal:




__





						Uxcell s14032800am0476 Red Mushroom Cap 1NO 1NC DPST Emergency Stop Push Button Switch AC 660V 10A: Wall Light Switches: Amazon.com: Industrial & Scientific
					

Uxcell s14032800am0476 Red Mushroom Cap 1NO 1NC DPST Emergency Stop Push Button Switch AC 660V 10A: Wall Light Switches: Amazon.com: Industrial & Scientific



					www.amazon.com
				




PZ


----------



## Sal_the_man

@B2 would you kindly post a short sample of g-code that you use in Mach3? Our test code works just fine but the g-codes generated from HSM and Freecad are not doing the trick. I've listed the processor as linuxcnc in freecad


----------



## B2

Hi Sal,
Will do.   I run 64 bit win7 enterprise and have only historic and limited experience with Linix.   

This is the first project I did on FREECAD and one of the first cuts I made on my PM 940M. I generated the CAD on FREECAD, used FREECAD to generate a tool path and then simulated it to see the results, then I again used FREECAD to generate the G-code.  I will upload it as a .txt file which it is.  

I did not really know what I was doing and so it took me a long time to get it done.  It was a heart shaped cut in a piece of brass for my wife.  (I need to show her that the mill could be usefull!!!) 

If I recall block size was 40x40x2mm and the cut was made from a small engraving tool.  

I am assuming that you have an .xml configuration file that is working now.  If not take the one that I uploaded earlier, change the extension from .doc to .xml and drop it in the Mach3 folder.  It should work.  I realized that maybe you are not running the Mach3 from its little start up program which gives you a choice of which configuration profile you want to install as Mach3 is booting.  It allows you to copy, delete, and I think rename profiles.   If not you may want to use this.  

My suggested steps (maybe to detailed). 

Take the tooling out of the mill....  for now.
Start Mach3 with a known profile.
After Mach3 is running, turn on the Mill power and hit the start button.
Control Tab to show the pendant and make sure its light is active.
Use the pendant, the manual commands, or even the manual cranks to move the spindle position to the middle of the x and y position and raise the z a few inches above the table, vise, etc.
In Mach set the the x, y, and z positions readings to zero.  (i.e. put your software origin in the middle of the stages)
load the Gcode file
In the tool path side window you should now see a square with the trace of a heart more or less filling the square.
Click on a line of the G code to active the windown and then with the up and down keys you can see the path of the part lighting up as you click up and down line by line.
The code is written in metric mm and so once the Gcode is loaded so are the readings in Mach3.  X, Y, X are shown in mm not inches.  Prior to loading the g-code the profile was in inches and so if your xyz positions are not initially zero the Gcode box and heart in the tool path screen will be way off in the corner of the screen some where and all you will see is the initial move.
If everything looks right, start the cycle.

What the code does is assumes the origin (center of the brass block I was working on) is where the mill  head is initially setting. Upon start up it loads settings, starts the spindle, then raises the tool, and moves off to near the top right corner of the block, lowers the tool into the work a little (0.1mm) and starts cutting the heart line.  It uses arcs and straight lines.  While this seems simple, it took me a while to figure out where to put the arc center and start and stop points including the tool offset etc.  

Let me know.  

Dave

PS.  I have written a number of other G-code, but if I can avoid doing a CAD first I try to.  That is the reason I like using the little Wizards built into Mach3.   I steal this gcode from the wizard and then modify it to do my simple parts.   

PS.  If you open this gcode .txt file in Notepad it may be difficult to view as it seems to word wrap.  However if you open it in in Notepad++ or even MS WORD you can view it just fine, line by line.  Or, if you just load it into Mach3 you will be able to see it line by line.  I am not for sure what is going on with Notepad.


----------



## B2

Hi Sal,

I got to thinking you might also want the FreeCad drawning, path gen, and the simulation file.  Attached.  However, once again the Hobby-machinist forum will not allow me to upload a file with a .FCStd extension.  So I have changed it to .123 and you can change it back to .FCStd and open it with FreeCad


----------



## B2

Hi Sal,

I could not get the .123 extension to send either, but then got it to attach using the dummy extension... .doc.  Anyway, you have to change it back to .FCStd to get FreeCad to accept the file. 

If you have not figured it out yet, there are three tool paths in the FreeCad file, but I only used the first one to generate the Gcode I sent.  If you want all three then you have to generate them separately in the FreeCad path generator and then either run them separately or manually put them together into a single larger file.  The other two paths generate the letter "G" and the third makes a small square hole for a chain or string to go through.  When made each of the tool paths cut all the way through the material.  The heart drops out of the block and it has the letter and hole cut in it.  

I am sure this could have all been done better, but this was my first FreeCad project.

I know that you ask for a small Gcode and I sent a large one, but I never made a small one in FreeCad and so would have to start from scratch.  If you still want a small set of code I will see if I can generate one for you using the Mach3 Wizard.  How about a something like just an arc, or a ring of drilled holes, or a slot?  

It is getting late.  I will try to get you one of those in the morning.  

Dave


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## B2

Good Morning Sal,

Per your request a couple of short Gcode programs attached. 

1) "cholepattern5-22_5 J101.txt"  This drills 5 holes along a circle path separated by 60 degrees starting at a phase angle of 22.5 degrees from the horizontal.  The circle radius is about an inch and it uses G73 drilling as I was working with plastic.  I ran this program using my Mach3.  So it should work.

2) "CutArcPressGaCover J121.txt"   Simply cuts moves in x to approach a point an arc start point, then moves through a semicircle arc (180 degrees) about 1 in in radius and then returns to the origin and drops down for more cuts.  I used this this to cut away a portion of a PVC tee pipe.  So it should work in Mach3.

3)  "ArcCutpocket - Copy.txt"   This uses a spiral cut to make a pocket hole and repeats the cut 4 times at incremental 1/4 inch cut depths.  I think it is about 1 inch in radius.  I did not run this but it seemed to simulated fine.

Good luck.  

Dave


----------



## B2

Hi Sal,

I have not heard from you for a while.  Hope your efforts are paying off...?

Recently, I have been using FreeCAD to design some involute gears to convert my old South Bend 10 to make metric threads pitches and in reviewing the G-code Post Processors, I seem to get the best code generated with I use the "dynapath" Post Processor.  It seems several of the other available post processors yield code that almost works, but commonly an incorrect feed rate.  I think the G-code that I posted for the heart cut was generated using the "grbl" post processor, but I may have edited the Gcode to correct the feed rates ... as what I put into the tool profile does not show up in the G-codes generated by the post processor.  However, dynapath, seems to work.    Sometimes there is no feed rate entered, but other times there is an unreasonably high value which always seems to be the same (a default setting?).  Below is the info on my version of FreeCAD and how I am running it.  I picked this up off the Help About page of FreeCAD.

OS: Windows 7
Word size of OS: 64-bit
Word size of FreeCAD: 64-bit
Version: 0.17.13522 (Git)
Build type: Release
Branch: releases/FreeCAD-0-17
Python version: 2.7.14
Qt version: 4.8.7
Coin version: 4.0.0a
OCC version: 7.2.0
Locale: English/UnitedStates (en_US)

Since there is no specific FreeCAD post processor installed specifically to generate Gcode for our Mill/Mach3 (nor for Acorn) I guess I am lucky these work as well as they do.  

Dave


----------



## Sal_the_man

Sorry for my late response @B2, I was out of the office for a few days due to an emergency. I've got time today to give your codes a shot. Thanks for the abundant help, @chocadile and I really appreciate it


----------



## Sal_the_man

@B2 your g-codes are working perfectly. So our post processor is the culprit


----------



## Sal_the_man

Our spindle for some reason has stopped working. I'm inclined to believe this is our problem. However, whenever I put in a velocity value it does not register my input and automatically goes to "0"

Thoughts?


----------



## B2

Hi Sal,
I really do not have any ideas other than bad wires. But I did check my machine out and here is what I found.  

While my spindle motor movement profile is different from your photo, but it does not seem to matter what the settings are.... the spindle still works when I issue the M3 S### command or if I hit the spindle on and off button on the spindle window in Mach3.  In fact, if you use the M3 S0 the spindle turns at very low rpm.  M5 to stop the spindle.  I even went so far as to set all of the settings in the spindle movement profile to zeros and the spindle still seemed to work fine with the manual commands.   Initially, my spindle motor movement profile was: 

 (interchanged from yours)
Steps per : 1
Velocity: 120
other settings are the same as you show in your photo.  However, in the graph there is a straight sloped line starting at 0,0 and going up to the top right corner 0.5 sec, 120 inches per minute, indicating that the velocity was always increasing and would reach the max setting at 1/2 second.  Of course the units of this screen are all nonsense.... what does velocity mean for a rotating spindle?   It should be in RPM or something.  The software engineer cheated here and used the same screen as for the other axes!  Poor!  In fact, I think this entire screen maybe a in active.  There must be somewhere else in the software/code that actually controls the spindle max RPM? 

It would seem that with zero velocity that the spindle would not turn, but it did not seem to care on my machine.  In fact, as I stated above, I set every entry on this screen to zero and hit the Spindle: Save Axis Settings so that all the readings would be zero, and my spindle could still be programed to run.  So, these settings seemed to have nothing to do with the spindle turning.  However, I should also tell you that once I had set all entries to zero I could not put the velocity value back!  I would type in other values but the screen always put it back to zero.    It always read zero and I tried a lot of things to get it to some other value!  Since yours is reading zero already, you may not be able to change it to a non-zero value in/from this screen.    So I restored my profile from one of the back up folders. 

If you have not discovered the location of these, there under the sub folder: Mach3/XMLbackups or something like this.  There should be a bunch of them as it seems to save a back up every so often.    Likewise you seem to need a folder in the Mach3/macros sub-folder which has the same name as the profile and contains a hole bunch of little program setting files.  If you look in the macro folder you should also see a folder name Mach3Mill.   I think it was the folder first created when I installed Mach3.  (By the way, I found that if I just double clicked on the .xml file that Windows explorer would open and show the contents of the file in line by line format.  So at least you can read it even if it does not mean anything to you.  I suspect that if one does a file compare between a profile that is working and one that is not working we might be able to decipher which line changes as configuration settings are changed.

So grab one of your backup .xml files, copy it to the main Mach3 folder, and change its extension from what ever the backup nomenclature is (example .xb3 etc) to .xml.  Then make sure that there is a folder in your Mach3/macros folder with the same name and which contains all of the little files that the Mach3Mill folder contains.  Start the Mach3 loader and choose the new profile (the one you just created from the back up profile .xml).  After the Mach3 launches see if the spindle motor settings are restored to some other value than you show in your photo.  It may not enable your spindle to work, but at least you will know it is not in the software.  

Motor not running:  bad connections?  bad VFD? bad motor?   Hidden interlock?   I think I read that the VFD simply wants to see a DC input voltage between 0-10v to go from 0 to ~400 Hz to drive the motor.   So in concept you could disconnect the wiring and connect a 1.5volt battery to the inputs to start the spindle turning.  Anyway, you can look up the specs/manual on the VFD.  

Good luck.  

Dave L.


----------



## Sal_the_man

B2 said:


> Hi Sal,
> I really do not have any ideas other than bad wires. But I did check my machine out and here is what I found.
> 
> While my spindle motor movement profile is different from your photo, but it does not seem to matter what the settings are.... the spindle still works when I issue the M3 S### command or if I hit the spindle on and off button on the spindle window in Mach3.  In fact, if you use the M3 S0 the spindle turns at very low rpm.  M5 to stop the spindle.  I even went so far as to set all of the settings in the spindle movement profile to zeros and the spindle still seemed to work fine with the manual commands.   Initially, my spindle motor movement profile was:
> 
> (interchanged from yours)
> Steps per : 1
> Velocity: 120
> other settings are the same as you show in your photo.  However, in the graph there is a straight sloped line starting at 0,0 and going up to the top right corner 0.5 sec, 120 inches per minute, indicating that the velocity was always increasing and would reach the max setting at 1/2 second.  Of course the units of this screen are all nonsense.... what does velocity mean for a rotating spindle?   It should be in RPM or something.  The software engineer cheated here and used the same screen as for the other axes!  Poor!  In fact, I think this entire screen maybe a in active.  There must be somewhere else in the software/code that actually controls the spindle max RPM?
> 
> It would seem that with zero velocity that the spindle would not turn, but it did not seem to care on my machine.  In fact, as I stated above, I set every entry on this screen to zero and hit the Spindle: Save Axis Settings so that all the readings would be zero, and my spindle could still be programed to run.  So, these settings seemed to have nothing to do with the spindle turning.  However, I should also tell you that once I had set all entries to zero I could not put the velocity value back!  I would type in other values but the screen always put it back to zero.    It always read zero and I tried a lot of things to get it to some other value!  Since yours is reading zero already, you may not be able to change it to a non-zero value in/from this screen.    So I restored my profile from one of the back up folders.
> 
> If you have not discovered the location of these, there under the sub folder: Mach3/XMLbackups or something like this.  There should be a bunch of them as it seems to save a back up every so often.    Likewise you seem to need a folder in the Mach3/macros sub-folder which has the same name as the profile and contains a hole bunch of little program setting files.  If you look in the macro folder you should also see a folder name Mach3Mill.   I think it was the folder first created when I installed Mach3.  (By the way, I found that if I just double clicked on the .xml file that Windows explorer would open and show the contents of the file in line by line format.  So at least you can read it even if it does not mean anything to you.  I suspect that if one does a file compare between a profile that is working and one that is not working we might be able to decipher which line changes as configuration settings are changed.
> 
> So grab one of your backup .xml files, copy it to the main Mach3 folder, and change its extension from what ever the backup nomenclature is (example .xb3 etc) to .xml.  Then make sure that there is a folder in your Mach3/macros folder with the same name and which contains all of the little files that the Mach3Mill folder contains.  Start the Mach3 loader and choose the new profile (the one you just created from the back up profile .xml).  After the Mach3 launches see if the spindle motor settings are restored to some other value than you show in your photo.  It may not enable your spindle to work, but at least you will know it is not in the software.
> 
> Motor not running:  bad connections?  bad VFD? bad motor?   Hidden interlock?   I think I read that the VFD simply wants to see a DC input voltage between 0-10v to go from 0 to ~400 Hz to drive the motor.   So in concept you could disconnect the wiring and connect a 1.5volt battery to the inputs to start the spindle turning.  Anyway, you can look up the specs/manual on the VFD.
> 
> Good luck.
> 
> Dave L.



Thanks B2. Gonna give your advice a shot. I had our VFD working briefly but it was flashing the "-LU-" code prior to shutting down. So it very well may be a hardware issue.

Going to back up one of the files anyway


----------



## phazertwo

The VFD also needs a signal to tell it to run and what direction to run.  There are two replays in the cabinet for this.... I think they are KA1 and KA2, but I can't remember and don't have my diagram with me.

You have to make sure that your outputs are addressed correctly, then it _should_ work.  I would start there, then check to make sure the outputs are actually lighting up.

PZ


----------



## Sal_the_man

phazertwo said:


> The VFD also needs a signal to tell it to run and what direction to run.  There are two replays in the cabinet for this.... I think they are KA1 and KA2, but I can't remember and don't have my diagram with me.
> 
> You have to make sure that your outputs are addressed correctly, then it _should_ work.  I would start there, then check to make sure the outputs are actually lighting up.
> 
> PZ



Roger that. KA1 is to have it turn CW and KA2 is for it to turn CCW. 

KA1 is getting power and is activating correctly. Haven't tried KA2.


----------



## phazertwo

A signal wire comes from the VFD to KA1 and is jumped to KA2, and which ever relay is activated feeds that signal back to the VFD.  Make sure that it's making the whole trip.  I would be willing to put money on a loose connection.

PZ


----------



## Sal_the_man

Hey shout out to @phazertwo and @B2 ! It was indeed a poorly connected ground wire (blue #011) located at one the fuses. I was able to pull it out by hand actually, so just re-tightened it and voila the VFD fired up!

Did our carving which seems more like an oval than a circle. But hey something is better than nothing.

Spindle seems to be spinning slower than we previously had it so it's probably my doing in the software settings. Going to revisit that again.

But man you guys are awesome. @chocadile and I are feeling pretty good today about our first cut using @B2 's file!


----------



## B2

Sal,
Great News! 

I think you used the "ArcCutpocket - Copy.txt" file I posted.
Check out the path display in Mach3 and see if it looks oval verse round.....  Maybe it is oval? I think this is the set of code that came from the wizard, I never actually ran it, but the simulation looked good. Anyway, there is no simple G code to actually make a true spiral pocket so they typically use a series of round arcs with the origin effectively moving.  I think the code calls for a series of 180 arcs each one progressively smaller but starting from where the last one left off.  This is common.   Anyway, I wanted to make a spiral shaped cone and never found a simple G code to do so. 

So go to path, highlight the code in the left window and step down through the code line by line.  In the path window you should see the individual cuts lighting up as you go.  Hence, you can follow the 180 arcs.

Anyway, a single G2 command will essentially generate a circle for you.  use a point and see if it comes back to where it started on the circle.  If not an axis maybe missing steps.  Why missing steps:  motor coupling loose?  mechanical binding?  etc. Poor electrical connection? motor traverse profile acceleration or velocity too high? (P2 and I were discussing max velocities earlier in this post , so you can see our numbers there, Feb 22, 2019  .) etc.


----------



## Sal_the_man

B2 said:


> Sal,
> Great News!
> 
> I think you used the "ArcCutpocket - Copy.txt" file I posted.
> Check out the path display in Mach3 and see if it looks oval verse round.....  Maybe it is oval? I think this is the set of code that came from the wizard, I never actually ran it, but the simulation looked good. Anyway, there is no simple G code to actually make a true spiral pocket so they typically use a series of round arcs with the origin effectively moving.  I think the code calls for a series of 180 arcs each one progressively smaller but starting from where the last one left off.  This is common.   Anyway, I wanted to make a spiral shaped cone and never found a simple G code to do so.
> 
> So go to path, highlight the code in the left window and step down through the code line by line.  In the path window you should see the individual cuts lighting up as you go.  Hence, you can follow the 180 arcs.
> 
> Anyway, a single G2 command will essentially generate a circle for you.  use a point and see if it comes back to where it started on the circle.  If not an axis maybe missing steps.  Why missing steps:  motor coupling loose?  mechanical binding?  etc. Poor electrical connection? motor traverse profile acceleration or velocity too high? (P2 and I were discussing max velocities earlier in this post , so you can see our numbers there, Feb 22, 2019  .) etc.



@B2 your hyperlink regarding max velocities and the motor settings was an absolute gem. Fixed our travel settings to a tee.

I also fixed out physical E-stop button, the wrong port & pin were specified.

Now...one last problem before we're 100% functional! The spindle speed RPM does not register on mach 3. It spins at an arbitrary value. I do not have it set to the PWM controller, so I presume this is another port/pin issue?

Our VFD is functioning of course since I am able to spin the spindle


----------



## B2

Hi Sal,

I am glad my velocity settings were of use.  WRT to the spindle speed, I will not be near my 940 until next week.  However, if you have specific measurements or Mach3 setting observations you would like for me to make I will try to do so.  Just let me know.    

If you have a volt ohm meter (VOM) you could measure the speed input voltage (DC voltage) at the VFD to see what it is set at.  You did not mention what rpm your spindle was turning at, but from your first cut photo it is obviously turning at some reasonable speed.  The VFD input voltage is suppose to be between 0 and 10 volts (DC) for min to max speed, respectively.  If it happened to be connected in error to one of the logic level pins it might be around 4-5 volts and would cause the spindle to turn at roughly 1/2 max speed.  If you do not have a VOM you can get a cheap one at Harbor Freight or on the internet. Harbor Freight has a poor quality one that they some times promote for around $5, but it works for most simple measurements.  Amazon probably has be better one for $11-$25.  A really good one would cost several  hundred $ (Fluke).

When I first got my 940 I checked my spindle speed against the Mach3 settings.  Of course Mach3 does not know about the mechanical gearing and so just reads between 0 and 1000 rpm even if the gears are changed to cause the spindle to be 3200 rpm max.  Nevertheless, I found that the speed displayed by Mach3 was about 10% off from the actual speed.  

To do this measurement I used an optical strobe.   I had a digital function generator which yields an accurate square wave or pulse wave frequency reading.  I used the generator to drive a bright LED and put a piece of white tape on one of the splines on the spindle shaft.  I turned on the spindle and then adjusted the generator frequency until the optically strobed white tape appeared to be stationary.   With one measurement made I then could change the Mach3 settings and adjust the generator frequency to the speed it should be and see if the strobed tape was again stationary.  Things were not perfect, but were reasonable given that everything is open loop and analog.   

If you want to get a function generator or a pulse counter you can purchase a cheap one from Banggood or Aliexpress, but shipping from China will take a month or so.  Ihave no idea if they are any good.   I do not know what Harbor freight might have.  Amazon will have a digital function generator, but will cost at least $60-70.  A really good one will cost a lot more.  Here is a generator URL that might work.  The specs do not say anything about the load that it would drive except TTL.  Normally a funciton generator would drive a 50 Ohm load.  From this one can calculate how to connect a raw LED.     https://www.amazon.com/KKmoon-Preci...l+function,aps,188&sr=8-5#feature-bullets-btf

Example LEDs:    https://www.amazon.com/DiCUNO-Emitt...lectronic+led&qid=1553746085&s=gateway&sr=8-3 

If you want to pursue all of this and do not have an electronics background I can provide more details.  

Dave L.

PS.  I another Amazon search for a tachometer.  This might be a better method for measuring the rotational speed and only costs $17.  Amazon has a review movie where someone was measuring spindle speed!!!   it only appears to go up to 1000 rpm, but that is probably good enough.  
https://www.amazon.com/AGPtek®-Prof...&qid=1553746280&s=gateway&sr=8-26-spons&psc=1


----------



## Sal_the_man

B2 said:


> Hi Sal,
> 
> I am glad my velocity settings were of use.  WRT to the spindle speed, I will not be near my 940 until next week.  However, if you have specific measurements or Mach3 setting observations you would like for me to make I will try to do so.  Just let me know.
> 
> If you have a volt ohm meter (VOM) you could measure the speed input voltage (DC voltage) at the VFD to see what it is set at.  You did not mention what rpm your spindle was turning at, but from your first cut photo it is obviously turning at some reasonable speed.  The VFD input voltage is suppose to be between 0 and 10 volts (DC) for min to max speed, respectively.  If it happened to be connected in error to one of the logic level pins it might be around 4-5 volts and would cause the spindle to turn at roughly 1/2 max speed.  If you do not have a VOM you can get a cheap one at Harbor Freight or on the internet. Harbor Freight has a poor quality one that they some times promote for around $5, but it works for most simple measurements.  Amazon probably has be better one for $11-$25.  A really good one would cost several  hundred $ (Fluke).
> 
> When I first got my 940 I checked my spindle speed against the Mach3 settings.  Of course Mach3 does not know about the mechanical gearing and so just reads between 0 and 1000 rpm even if the gears are changed to cause the spindle to be 3200 rpm max.  Nevertheless, I found that the speed displayed by Mach3 was about 10% off from the actual speed.
> 
> To do this measurement I used an optical strobe.   I had a digital function generator which yields an accurate square wave or pulse wave frequency reading.  I used the generator to drive a bright LED and put a piece of white tape on one of the splines on the spindle shaft.  I turned on the spindle and then adjusted the generator frequency until the optically strobed white tape appeared to be stationary.   With one measurement made I then could change the Mach3 settings and adjust the generator frequency to the speed it should be and see if the strobed tape was again stationary.  Things were not perfect, but were reasonable given that everything is open loop and analog.
> 
> If you want to get a function generator or a pulse counter you can purchase a cheap one from Banggood or Aliexpress, but shipping from China will take a month or so.  Ihave no idea if they are any good.   I do not know what Harbor freight might have.  Amazon will have a digital function generator, but will cost at least $60-70.  A really good one will cost a lot more.  Here is a generator URL that might work.  The specs do not say anything about the load that it would drive except TTL.  Normally a funciton generator would drive a 50 Ohm load.  From this one can calculate how to connect a raw LED.     https://www.amazon.com/KKmoon-Precision-Dual-channel-Generator-Arbitrary/dp/B014KT3IT6/ref=sr_1_5?crid=188CMPJLMZUXV&keywords=digital+function+signal+generator&qid=1553745100&s=gateway&sprefix=digital+function,aps,188&sr=8-5#feature-bullets-btf
> 
> Example LEDs:    https://www.amazon.com/DiCUNO-Emitt...lectronic+led&qid=1553746085&s=gateway&sr=8-3
> 
> If you want to pursue all of this and do not have an electronics background I can provide more details.
> 
> Dave L.
> 
> PS.  I another Amazon search for a tachometer.  This might be a better method for measuring the rotational speed and only costs $17.  Amazon has a review movie where someone was measuring spindle speed!!!   it only appears to go up to 1000 rpm, but that is probably good enough.
> https://www.amazon.com/AGPtek®-Professional-Digital-Tachometer-Contact/dp/B004Q8L894/ref=sr_1_26_sspa?keywords=optical+strobe&qid=1553746280&s=gateway&sr=8-26-spons&psc=1



Thanks Dave.

Would you kindly share the ports & pins table with us? I think that is our root cause.

If I'm interpreting the wiring diagram correctly, all my limit & home switches are wired to *port 1 *in our CNC controller. However, in the Mach software I have to configure it to *port 2* in order for it to operate. So I'm guessing the spindle, VFD controller is also wrongly specified in our software even though it is correctly wired to the controller and in the cabinet.


----------



## B2

Hi Sal,
Took a lot (34) of photos for you today showing settings in Mach3 as well as some of the wiring in my PM-940M CNC.  However, just in case your machine's wiring is different I will first post my PM-940M CNC "Owner's Manual" which I got when my machine was shipped.   From your Feb26 photos the 940M components in the control box are laid out in a little different geometry than are mine, this causes my nMotion box to be mounted upside down from the word nMotion.   Likewise, some of the wiring control wire numbers differ.  It looks like most of your limit switch wire numbers are inverted from mine as well as being different in color.  For example, 059 and 057 are interchanged.  This seems to be true for each pair of these!  Likewise, some of the output wire numbers differ.     For the most part, I think my machine is wired up as the wiring diagrams show in my manual.  I inserted a few comments in the pdf manual file.

In my photos, I tired to turn the wire labels so that the numbers would show.  Interestingly, when I tugged on one of the wires going to the VFD the wire pulled right out of the crimp connector!  You may want to go from connection to connection and simply tug on the wire a little!!!!

I have never posted this many photos before, so I am going to do one first and see if the thumbnail versions come through as full resolution.  

Dave


----------



## B2

Hi Sal,  
I am still a newbie at Forum postings and so do not know if there is a better way to post these photos.  Because there were so many images I will not post them as individual images.  Because the resolution maybe important for you to be able to see the finer details of the images I did not want to simply upload them as thumbnails.  So, I have put them into pdf files.  As I said before, there are 34 photos, so you can determine if you got all that I posted.  

Good luck,
Dave


----------



## Sal_the_man

Awesome, thanks a bunch Dave. Going to dig through them now


----------



## Sal_the_man

Our wiring is different and looks like I do not have the two other wires exiting from the top of my VFD as marked with the blue streaks.

I'm going to look at your wiring diagram and compare it to mine. This is odd.

Our spindle works, but the RPM setting is nowhere near what I physically measure with my naked eye (and a paint mark). In addition, we are still getting a reading of zero RPM in both screenshots even though the spindle is operating and spins higher/slower according to my setting.


----------



## Sal_the_man

In addition, our software settings are nearly identical with exception to the angular headstock motor which we seem to have removed from the machine.


----------



## B2

Sal_the_man said:


> Our wiring is different and looks like I do not have the two other wires exiting from the top of my VFD as marked with the blue streaks.
> 
> I'm going to look at your wiring diagram and compare it to mine. This is odd.
> 
> Our spindle works, but the RPM setting is nowhere near what I physically measure with my naked eye (and a paint mark). In addition, we are still getting a reading of zero RPM in both screenshots even though the spindle is operating and spins higher/slower according to my setting.



Hi Sal,

Glad to hear you got my photos.  It did take me a while to capture them so that you could read them.  I do not regret doing this as it provides a record for me if my system ever stops working!  In fact, I am reviewing/learning quite about a bit about my machine in trying to help you out.  

I think I see part of your issue in the photo of the spindle speed.  The spindle speed is limited by the VFD max Hz out limit, which if I recall maybe about 400Hz.  The gearing of the Mill then determines the max RPM of the spindle.  There are two mechanical settings, one for up to 980 RPM and the other for upto 3200 RMP.    The Mach3 software puts out a digital number to the nMotion based upon the RPM you put in. But, this is just a maximum binary number.  The nMotion then used this to output a DC voltage to the VFD,where the maximum binary number corresponds to 10 Volts DC to the VFD.  The max voltage the VFD wants to see is 10 V DC and it then generates 400Hz sine waves to the motor.   Sure in Mach3, you select an RPM,  which is artificial as one can only get a max frequency out of the VFD.  Meanwhile one can setup the Mach3 software to readout any RMP value based upon the pulley configuration you tell Mach3 the Mill is using!  We do not have pulleys, but we do have gears.    Under the configuration tab pull down there is a place for pulley selection.  In mine, under pulley1 there is a max reading of 1000 RPM and when this is put into the setting then on the Spindle speed screen the max you can type in is 1000. Your software most likely has 1500 as the setting under pulley1.   I think you can make this any number you want, but when you spin up the spindle the VFD can only put out 400Hz.  If you want to go faster than this then you must switch the gear setting from the 0-980 to the the 3200 out put and the gear ratio makes the max speed now close to 3200.   The VFD is still only able to put out a 400Hz wave, so the motor is running at the same max speed.   My motor label actually indicates that the max frequency it is wanting to see is 200Hz.  So either, it is being pushed to a much higher RPM or the VFD is set to only put out a max of 200Hz for 10VDC input.  The motor label also says the motor will go up to 1390 rpm, but who knows that the gear ratio is between the motor and the spindle.  
Remember, we have no feed back to Mach3 so it has no idea what speed the spindle is turning, if it is turning at all! Hence, the RPM reading on the Mach3 window is unknown and listed at zero.  It is possible that there is a wiring problem, but my guess is that this is all software, and is almost irrelevant to actual operation.  So, I tried some more experiments.  I changed the pulley setting for pulley1 to 1500 rather than 1000 and sure enough, the Mach3 spindle speed window says the spindle is turning at 1500, but it is really only going the max of the VFD output frequency (~400Hz ?) to yield a spindle speed of about 1000RPM.    I also pulled up the motor turning configuration and looked at the spindle settings.  They do not change when one changes the pulley setting nor do they change for different spindle speeds selected.    After putting the pulley setting back to 1000, I ran a couple of other situations.  Setting the spindle speed to zero, the spindle will still turn very slowly.  I estimate about 1 turn per 1.5 second.  When I set the spindle speed to 20 RPM then I estimated the spindle to turn about 1 revolution each second, which would be 60 RPM, not 20!  This can be somewhat estimated via observation.  This low value is not unexpected as the DC control voltage (I did not measure it, but should) going from the nMotion to the VFD is probably not very accurate near the end of the scale of the nMotion digital to analog converter.  I would not expect yours to necessarily behave the same.     I then set the spindle speed to 200 RPM and sure enough it was going a lot faster.  I then pushed on the spindle over speed (S-ov) up(+) button and the speed increased accordingly (You can even hear the machine noise pitch increase).   However, when set to 1000 rpm, this button has no effect as the max speed has been reached.   

Through out all of this the Mach3 RPM reading is always zero, just as in your photo and mine.  This is probably because this reading box is only used if there is a tachometer on the spindle providing the feedback for an actual measurement!

So maybe there is some other setting in your Mach3 that is yielding a incorrect spindle speed.  I think I have sent you most of my setting photos, but maybe there is a pinout that is connected differently???

Just in case something else is wrong with the wiring I took more pictures of the wiring and will include them.  

WRT to the two "sets" of wires connected at the top of the VFD:  They have the same labels R1 and S1 (new picture provided) as the back wires.  The smaller diameter set of wires go "directly" to the spindle motor FAN, so as long as the motor is being cooled sufficently, I don't think these would be your issue. So, on my machine this is wired DIFFERENTLY from the ckt drawing in my owner's manual, pdf page#13 (and labels table pdf p12), where it shows the fan motor to be M4 and in the ckt drawing it show M4 to connected via breaker FU2 and relay KM1.  This is not the case, the fan is simply connected to the input (top) the VFD via R1 and S1!    By the way, just in case my spindle motor is different I will send photos of the motor label and its wiring connections.    One picture is for the fan, M4, connection at the top, and the other is to power the spindle motor, M1, the third is of the motor label and motor.  The other (larger diameter) set of R1 and S1 at the top of the VFD appear to come from the QM breaker.  It is interesting in the drawing p13 that the wires from QM to VFD have dots on them.  This usually means that their is a connection, but they do not show anything extra being connected here.  Anyway, as soon as the main power is turned on, before hitting the Green ON button on the control arm box, my spindle motor FAN starts running. The Spindle does not come on without turning it on with Mach3, which which requires both the software RESET button must be touched/on and the spindle on/off software button that indicates the VFD is being controlled by the software spindle on/off button.  

So to reiterate, if the other parts of the drawings, and my my look-see, are correct, the main power comes into a set of terminals at the bottom of my big electronics box and the output via these adjacent terminals which are labeled L and N (not L1 and N1 as shown in the manual) as well as the green-yellow (Neutral)  and then the L and N go to the main power switch on the side of the electronics cabinet while the green-yellow wire goes to a bunch of screw terminals for distribution. { By the way these two, L and N, are the two sides of the 220 volts and the N is NOT the neutral of my home breaker box.   I also ran a separate, 4th wire, ground wire to the mill.}     The output wires of my main power switch are labeled L2 and N2 and these distributed as shown at the top of the manual pdf page 13.  In particular they go to QM and become R1, S1 which feed the top of the VFD (and as mentioned my spindle motor fan!)  Indeed as the drawing shows for QM there is a wire the connects the top to the bottom and has no label numbers on it.  This QM seems overly complex, but maybe this is an option for folks who have a three phase power or something.  There do appear to be mechanical programing switches on QM.

Lastly, I think I mentioned it before, but some time ago, I used a strobe light to measure the actual spindle speed.  I do not recall exactly, but over most of the middle to upper spindle speed range the reading in Mach3 where I set the speed, was fairly close to the measured RPM,.... only about 5% -10% off.    

Best, 
Dave


----------



## B2

Hi Sal,

So I quickly measured the input pin voltage at the VFD as a function of the Mach3 spindle RPM setting.  The voltage between the VFD pins at wires 079 (ACM) and 081 (AVI) (see my earlier photo of the bottom of the VFD) varied reasonably linearly with Mach3 RPM setting.  For each 100 RPM increase in Mach3 the voltage at the VFD went up by 1 volt DC.  At 0 RPM it read .3VDC,  100 RPM it was 1.1VDC, 200 RPM yielded 2.0VDC, 300 RPM yielded 3.0, 500RPM yielded 5.0VDC, ... , 900 RPM yielded 8.9VDC, 1000 RPM yielded 9.9VDC.  

Dave


----------



## phazertwo

Sounds like you need to adjust the max frequency in the VFD.

PZ


----------



## B2

Hi Sal,
I woke up this morning thinking about your situation with the spindle speed.  I guess I may not fully understand all of your description of the spindle speed issue.  

You said:  "Our spindle works, but the RPM setting is nowhere near what I physically measure with my naked eye (and a paint mark). In addition, we are still getting a reading of zero RPM in both screenshots even though the spindle is operating and spins higher/slower according to my setting."

Fixing the  pulleys configuration setting to 1000 rather than 1500 should have help to remove some confusion, but should not change the maximum speed of the spindle.   Then setting the Mach3 Spindle Speed RPM to 1000 simply means that the actual spindle RPM is 100% of the VFD max setting.  Likewise, Mach3 Spindle Speed RPM at 500 would mean the spindle RPM is 50% of the VFD max setting.  Phazor2 maybe correct that the VFD internally maybe off, but I would not mess with it until you have exhausted the other possibilities.  (I have not read about how to adjust this yet.)  (By the way, if there truly is something wrong with your VFD component I think that PM warranties the parts for 3 years.?)

Also, from your comment above and  the screenshots we learned that.  1) zero RPM is always the case in Mach3 as there is no tachometer feedback and so there is nothing to be displayed in this box  2) "Spins higher/slower according to my settings"  I assumed this means that you are typing in a number in to the small button box "Spindle Speed" of the Spindle Speed  window and hitting enter to make it change.  At which point the spindle responds to the new speed.  If this is the case, then it seems to me a digital code is being sent to the nMotion and then a DC signal must being generated by the nMotion  and sent to the VFD pins via the input wires 079 (ACM) and 081 (AVI).  Hence, that is working.  So that leaves: 3)  "RPM setting is nowhere near what I physically measure"  This has no quantitative info except that you say that "the spindle spins higher/slower ....... as it should."  This makes me think that all is working but that you just have no real way to measure the physical speed.  

Short of you buying/borrowing  a simple strobe  type tachometer  there is not a lot you can do to ensure that the speed is calibrated/functioning properly.  

I used the following g-code to watch my spindle speed increment up from min to max."  Maybe you want to try it?

(In Mach3, the General Logic configuration check the box for G04 setting to Dwell in millisec.)
(Spindle to turns on at 60 rpm, then wait 10 seconds, then increase the spindle to 200, wait 10 sec., etc.)

M3 (spindle on) 
S 60 (spindle speed 60 rpm, one revol per second)
G4 P10000 (dwell 10000 milli seconds, 10 seconds)
S 100 (spindle speed 100 rpm)
G4 P10000 (dwell 10000 milli seconds, 10 seconds)
S 200 (spindle speed 200 rpm)
G4 P10000
S 300 
G4 P10000
S 400 
G4 P10000
S 500 
G4 P10000
S 600 
G4 P10000
S 700 
G4 P10000
S 800 
G4 P10000
S 900 
G4 P10000
S 1000 
G4 P10000
S 0
M5

This turns on the spindle, sets the speed to 60 rpm, then dwells at his speed for 10,000 milli seconds, then increments the speed up, dwells, etc etc etc.  If this code will not run for you then you might have to change the G4 setting in the General Configuration check boxes.  G4 P10000 is suppose to mean "Dwell for 10,000 milliseconds" where the P means milliseconds and is suppose to be independent of the machine configuration, but I found that I needed to check the configuration box for G4 indicating milliseconds.   I think this maybe because the G4 command is non-modal and is usually combined in the same line with another G code.

I ran this program and recorded the spindle motion for you.  Maybe this will give you a better feel for speeds.

Dave


----------



## Sal_the_man

Thanks @B2.

Going to give your suggestions a shot today.

Sorry for the delay. @chocadile and I have been booked with work recently.


----------



## Sal_the_man

B2 said:


> Hi Sal,
> I woke up this morning thinking about your situation with the spindle speed.  I guess I may not fully understand all of your description of the spindle speed issue.
> 
> You said:  "Our spindle works, but the RPM setting is nowhere near what I physically measure with my naked eye (and a paint mark). In addition, we are still getting a reading of zero RPM in both screenshots even though the spindle is operating and spins higher/slower according to my setting."
> 
> Fixing the  pulleys configuration setting to 1000 rather than 1500 should have help to remove some confusion, but should not change the maximum speed of the spindle.   Then setting the Mach3 Spindle Speed RPM to 1000 simply means that the actual spindle RPM is 100% of the VFD max setting.  Likewise, Mach3 Spindle Speed RPM at 500 would mean the spindle RPM is 50% of the VFD max setting.  Phazor2 maybe correct that the VFD internally maybe off, but I would not mess with it until you have exhausted the other possibilities.  (I have not read about how to adjust this yet.)  (By the way, if there truly is something wrong with your VFD component I think that PM warranties the parts for 3 years.?)
> 
> Also, from your comment above and  the screenshots we learned that.  1) zero RPM is always the case in Mach3 as there is no tachometer feedback and so there is nothing to be displayed in this box  2) "Spins higher/slower according to my settings"  I assumed this means that you are typing in a number in to the small button box "Spindle Speed" of the Spindle Speed  window and hitting enter to make it change.  At which point the spindle responds to the new speed.  If this is the case, then it seems to me a digital code is being sent to the nMotion and then a DC signal must being generated by the nMotion  and sent to the VFD pins via the input wires 079 (ACM) and 081 (AVI).  Hence, that is working.  So that leaves: 3)  "RPM setting is nowhere near what I physically measure"  This has no quantitative info except that you say that "the spindle spins higher/slower ....... as it should."  This makes me think that all is working but that you just have no real way to measure the physical speed.
> 
> Short of you buying/borrowing  a simple strobe  type tachometer  there is not a lot you can do to ensure that the speed is calibrated/functioning properly.
> 
> I used the following g-code to watch my spindle speed increment up from min to max."  Maybe you want to try it?
> 
> (In Mach3, the General Logic configuration check the box for G04 setting to Dwell in millisec.)
> (Spindle to turns on at 60 rpm, then wait 10 seconds, then increase the spindle to 200, wait 10 sec., etc.)
> 
> M3 (spindle on)
> S 60 (spindle speed 60 rpm, one revol per second)
> G4 P10000 (dwell 10000 milli seconds, 10 seconds)
> S 100 (spindle speed 100 rpm)
> G4 P10000 (dwell 10000 milli seconds, 10 seconds)
> S 200 (spindle speed 200 rpm)
> G4 P10000
> S 300
> G4 P10000
> S 400
> G4 P10000
> S 500
> G4 P10000
> S 600
> G4 P10000
> S 700
> G4 P10000
> S 800
> G4 P10000
> S 900
> G4 P10000
> S 1000
> G4 P10000
> S 0
> M5
> 
> This turns on the spindle, sets the speed to 60 rpm, then dwells at his speed for 10,000 milli seconds, then increments the speed up, dwells, etc etc etc.  If this code will not run for you then you might have to change the G4 setting in the General Configuration check boxes.  G4 P10000 is suppose to mean "Dwell for 10,000 milliseconds" where the P means milliseconds and is suppose to be independent of the machine configuration, but I found that I needed to check the configuration box for G4 indicating milliseconds.   I think this maybe because the G4 command is non-modal and is usually combined in the same line with another G code.
> 
> I ran this program and recorded the spindle motion for you.  Maybe this will give you a better feel for speeds.
> 
> Dave



Just ran your program for pulley 1. Going to give this a short for pulley 2 now!

In the video I mentioned yours is a bit faster but our spindle speed does seem similar upon review. Let me know your thoughts though.


----------



## Sal_the_man

Second test @B2


----------



## B2

Hi Sal,

Great! It looks like there is nothing wrong with your equipment, the PM940M nMotion and VFD are working and so is Mach3!  By my count you must have about everything working the way you want it!!!  Sounds like you are ready to make something cool.   Congratulations!

However, since you posted the two videos, and I see your G-code changed between the two runs, I think I realize some of the confusion.   You must be trying to use two different pulley set ups in Mach3.  This is as should be if you are trying to have your machine calibrated to the world i.e. other folks g-code.  

Clearly, the gear box label on the PM940M is screwball! The label reads:  position 1 and indicates a speed from ~90 to 980 rpm and for position 2 it indicates 1000 to 3200 rpm.    This is incorrect!  The reading for position 1 is ok, but for position 2 it should read something like  ~290 to 3200 rpm.  That is, the gear knob only changes the mechanical ratio by a factor of about 3.2x.  So why would the lower limit not be ~90x3.2~290.  As one turns the gear knob from position 1 to position 2 the intermediate gearing is changing to make the spindle turn faster for the same motor speed. It is not magically interacting with the computer!  The motor is turning at the same motor RPM range (which is a min to max as the frequency changes from the min to the max).   So I prefer to think of the Mach3/nMotion signal to the VFD as simply 0 to 10 volts DC.  0 volts signal from the nMotion causes the VFD to put out an almost zero frequency 220 volt sinewave and when at 10 volts from the nMotion the VFD puts out the 220 volt drive at its maximum frequency.  (I think this is around 400 cycles per second).

So in the Mach3 settings one has the choice of spindle speed settings via the choice of pulley settings.  However, all these do is to cause the DC voltage going to the VFD to range.  The settings in my Mach3 set up only uses a single pulley setting for a maximum speed of 1000 RPM.  So Mach3/nMotion sends 10 volts to achieve the maximum spindle speed and 0 volts to cause the minimum spindle speed.  So when the G-code setting is S1000 the Mach3 knows that this is the maximum speed and sends out 10 volts.  For S500 it sends out 5 volts and so the spindle speed is 5/10 =1/2 of the max motor speed.  With out changing any  of the Mach3 setting nor any of the G-code If one moves the PM940M gear knob to position 2 the speed would be 3.2x faster. 

So when I write G-code, I like to think of the S1000 value not as an actual speed, but as a percentage x 10 of the maximum possible spindle speed.  When I write my G-code, I know that S1000 will cause a spindle speed of 1000 rpm when on gear box knob setting #1, but the same S1000 code will cause a spindle speed of 3200 rpm when the gear box knob setting is #2.   

Additionally, I am not for sure why PM puts the lower limit on the gear box 2 position to be ~1000 rpm.  Clearly, one can run it at slower speeds than 1000 rpm while the gear box is on the high setting.  

My only thought on this is that motors are designed to run at 60 Hz.  Not 0 nor 400 Hz.  So we know that this motor will not be as efficient or have as much torque at the extreme low or high frequencies of the VFD, but as long the motor does not burn out it is ok.  The motor getting hot depends more on the load that you put it under than the speed.  Clearly if you try to turn the motor very slowly while the gear box is set to the high position, 2, then the motor may stall and then motor will over heat quickly.  However, my guess is that when you are trying to use the high spindle rpm values (gear setting 2) you are not going to be turning large diameter tools into steel anyway!  You are probably cutting wood or plastic or other soft materials.

One last comment.  You may not recall, but I measured my spindle speed verses the Mach3 programmed speed.  At S0 setting the spindle turns slowly, a few rpm, maybe 50.   The Mach3 speed control does not really start to kick in until spindle is going at about 100 rpm.  When at S1000, full speed, the spindle speed was a few percent, 5-10% off from what it was suppose to be.  Likewise, while not terrible, it was not linear between the Mach3 settings and the actual speed.  So, one should not worry about the exact speed all that much.

Have fun and let me know how things are going.

Dave L.


----------



## Sal_the_man

B2 said:


> Hi Sal,
> 
> Great! It looks like there is nothing wrong with your equipment, the PM940M nMotion and VFD are working and so is Mach3!  By my count you must have about everything working the way you want it!!!  Sounds like you are ready to make something cool.   Congratulations!
> 
> However, since you posted the two videos, and I see your G-code changed between the two runs, I think I realize some of the confusion.   You must be trying to use two different pulley set ups in Mach3.  This is as should be if you are trying to have your machine calibrated to the world i.e. other folks g-code.
> 
> Clearly, the gear box label on the PM940M is screwball! The label reads:  position 1 and indicates a speed from ~90 to 980 rpm and for position 2 it indicates 1000 to 3200 rpm.    This is incorrect!  The reading for position 1 is ok, but for position 2 it should read something like  ~290 to 3200 rpm.  That is, the gear knob only changes the mechanical ratio by a factor of about 3.2x.  So why would the lower limit not be ~90x3.2~290.  As one turns the gear knob from position 1 to position 2 the intermediate gearing is changing to make the spindle turn faster for the same motor speed. It is not magically interacting with the computer!  The motor is turning at the same motor RPM range (which is a min to max as the frequency changes from the min to the max).   So I prefer to think of the Mach3/nMotion signal to the VFD as simply 0 to 10 volts DC.  0 volts signal from the nMotion causes the VFD to put out an almost zero frequency 220 volt sinewave and when at 10 volts from the nMotion the VFD puts out the 220 volt drive at its maximum frequency.  (I think this is around 400 cycles per second).
> 
> So in the Mach3 settings one has the choice of spindle speed settings via the choice of pulley settings.  However, all these do is to cause the DC voltage going to the VFD to range.  The settings in my Mach3 set up only uses a single pulley setting for a maximum speed of 1000 RPM.  So Mach3/nMotion sends 10 volts to achieve the maximum spindle speed and 0 volts to cause the minimum spindle speed.  So when the G-code setting is S1000 the Mach3 knows that this is the maximum speed and sends out 10 volts.  For S500 it sends out 5 volts and so the spindle speed is 5/10 =1/2 of the max motor speed.  With out changing any  of the Mach3 setting nor any of the G-code If one moves the PM940M gear knob to position 2 the speed would be 3.2x faster.
> 
> So when I write G-code, I like to think of the S1000 value not as an actual speed, but as a percentage x 10 of the maximum possible spindle speed.  When I write my G-code, I know that S1000 will cause a spindle speed of 1000 rpm when on gear box knob setting #1, but the same S1000 code will cause a spindle speed of 3200 rpm when the gear box knob setting is #2.
> 
> Additionally, I am not for sure why PM puts the lower limit on the gear box 2 position to be ~1000 rpm.  Clearly, one can run it at slower speeds than 1000 rpm while the gear box is on the high setting.
> 
> My only thought on this is that motors are designed to run at 60 Hz.  Not 0 nor 400 Hz.  So we know that this motor will not be as efficient or have as much torque at the extreme low or high frequencies of the VFD, but as long the motor does not burn out it is ok.  The motor getting hot depends more on the load that you put it under than the speed.  Clearly if you try to turn the motor very slowly while the gear box is set to the high position, 2, then the motor may stall and then motor will over heat quickly.  However, my guess is that when you are trying to use the high spindle rpm values (gear setting 2) you are not going to be turning large diameter tools into steel anyway!  You are probably cutting wood or plastic or other soft materials.
> 
> One last comment.  You may not recall, but I measured my spindle speed verses the Mach3 programmed speed.  At S0 setting the spindle turns slowly, a few rpm, maybe 50.   The Mach3 speed control does not really start to kick in until spindle is going at about 100 rpm.  When at S1000, full speed, the spindle speed was a few percent, 5-10% off from what it was suppose to be.  Likewise, while not terrible, it was not linear between the Mach3 settings and the actual speed.  So, one should not worry about the exact speed all that much.
> 
> Have fun and let me know how things are going.
> 
> Dave L.



@B2 you've been our guide and savior! @chocadile and I can't thank you enough for all the help you've given us.

Only thing left was to convert the inches to mm for my motor tuning and voila we've had successful passes on our wood stock. 

Slowly getting used to FreeCAD for using the Mill and imagine it will take some time.

Again, thanks a bunch. We're very excited to have this running!


----------



## B2

Hi Sal,

Great to hear from you and to see your movie.  You are welcome for any assistance I may have provided.    I look forward to hearing about your builds and tricks to make my machine run better.    Also, I also am still feeling my way with FreeCad.  Any FreeCAD tricks you find that are handy I would like to know about. 

Regards,

Dave

PS. 
I think I may have mentioned it, but I am now using the Linuxcnc, FreeCad Path converter.  Several of them seem to work to some degree  ... with slightly different results, but Linuxcnc seems to work as well as any of them.   Some do not work at all. 

These also seem to work: Centroid, grbl, Phillips (some differences, uses X,Y, theta, R and seems to interchange Y with Z), smoothie (somewhat, speed seems screwed up).  Dynapath works but has some problems in pre and post.  Did not work at all for me: openshop, rml, comparams. 

None of them are good at some functions and the more complex the shape, the more wasted cuts they seem to make.  Lots of jumping around on the part.  I tend to make a first past at a drawing and path generation with FreeCad and then go into the G-code and fix it up .... sometimes a lot.


----------



## megaplow

Circling back to the conduit. I just found some on Amazon that comes in reasonable lengths. 





						Electriduct 1/4" PVC Coated Liquid-Tight Galvanized Steel Flexible Metal Conduit - 10 Feet - - Amazon.com
					

Electriduct 1/4" PVC Coated Liquid-Tight Galvanized Steel Flexible Metal Conduit - 10 Feet - - Amazon.com



					www.amazon.com


----------



## szenieh

megaplow said:


> Circling back to the conduit. I just found some on Amazon that comes in reasonable lengths.
> 
> 
> 
> 
> 
> Electriduct 1/4" PVC Coated Liquid-Tight Galvanized Steel Flexible Metal Conduit - 10 Feet - - Amazon.com
> 
> 
> Electriduct 1/4" PVC Coated Liquid-Tight Galvanized Steel Flexible Metal Conduit - 10 Feet - - Amazon.com
> 
> 
> 
> www.amazon.com


Would you be able to tell me the CL-to-CL distance on the holes at the bottom of the cast iron base of the PM940? I am trying to attach a flat bar to these holes and would love to confirm the distance.  My rough measurement is 16".

Thanks


----------



## B2

When I got my 940M-VS-CNC the base was not mounted.  I flipped it over and tried to measure the base holes and locations.  My general impression was that they were not on a square and that they were crooked compared to the outer edges of the base. They were just rough holes in the casting.   I.e. they were just some holes/sticks left in the poor quality sand casting mold that the iron was poured into.  Anyway, after a lot of worry about how to fasten a base plate to the stand holes I made a compromise and made the holes in my mounting base plate to be on a rectangular pattern with a spacing for the center to center hole spacing at  15.8" x 17.8"  I drilled 5/8" diameter holes .  However, since these bases are probably made from individual sand molds and the holes in the sand mold were probably made by someone just shoving in some sticks there is no reason that they should all be the same.  Anyway, it has been several years now, but if I recall I drilled 5/8" through holes in my base plated and then used 1/2" bolts to go through the stand holes and the base plate holes and this was enough extra space that it all fit.   

On to my base plate I mounted casters to be able to wheel the mill around.  Once it is in place I block it to prevent any motion during operation. 
You can see a picture of the final casters and base plate with the mill stand etc mounted here:




B2 said:


> Yes, I too purchased a PM-940M CNC VSD (Pre-assembled) with all 4 axes.


If you really want I can send you some drawings I made for my base plate and how it was assembled for the casters.  I made the base plate from 4 flat bars and bolted them together via the casters.  I did all this drilling using the CNC mill before it even came off of the pallet and it was sitting on the pallet on the garage floor!  However, if I were to do it over I would just purchase a sold steel plate of the right size and then have someone plasma cut it with a void in the center to reduce the weight and the holes.  I think @ptrotter did something like this after we talked about it.  

Dave L.


----------



## szenieh

B2 said:


> When I got my 940M-VS-CNC the base was not mounted.  I flipped it over and tried to measure the base holes and locations.  My general impression was that they were not on a square and that they were crooked compared to the outer edges of the base. They were just rough holes in the casting.   I.e. they were just some holes/sticks left in the poor quality sand casting mold that the iron was poured into.  Anyway, after a lot of worry about how to fasten a base plate to the stand holes I made a compromise and made the holes in my mounting base plate to be on a rectangular pattern with a spacing for the center to center hole spacing at  15.8" x 17.8"  I drilled 5/8" diameter holes .  However, since these bases are probably made from individual sand molds and the holes in the sand mold were probably made by someone just shoving in some sticks there is no reason that they should all be the same.  Anyway, it has been several years now, but if I recall I drilled 5/8" through holes in my base plated and then used 1/2" bolts to go through the stand holes and the base plate holes and this was enough extra space that it all fit.
> 
> On to my base plate I mounted casters to be able to wheel the mill around.  Once it is in place I block it to prevent any motion during operation.
> You can see a picture of the final casters and base plate with the mill stand etc mounted here:
> 
> 
> 
> If you really want I can send you some drawings I made for my base plate and how it was assembled for the casters.  I made the base plate from 4 flat bars and bolted them together via the casters.  I did all this drilling using the CNC mill before it even came off of the pallet and it was sitting on the pallet on the garage floor!  However, if I were to do it over I would just purchase a sold steel plate of the right size and then have someone plasma cut it with a void in the center to reduce the weight and the holes.  I think @ptrotter did something like this after we talked about it.
> 
> Dave L.


I would love to take a peek at your drawings for this machine. I have a design, but it would help to see what you did.
Thanks for taking the time to answer.

Salah


----------



## szenieh

Here are some snapshots from solidworks for the PM940CNC cast iron base.


















I am using CarryMaster ALC-1000-FB









My current measurement for CL-to-CL of the mounting holes is 16". I can check more accurately once I jack the machine up and remove the old leveling feet. I might slip a 2x4 under the 2 holes (2 front and 2 back) and center-punch it with a custom-made transfer punch 1/2" in diameter.

The machine is already mounted on top of the base making it hard for me to take that measurement.


----------



## B2

Hi Salah,     Are you related to Sal_the_Man who I was working with on this string some time ago?

Nice photos and CAD sketches.  Did you repaint the base.  Mine is green! I will come back to the 940 base plate and casters, but  I was curious about when you got your 940M-CNC so I looked at some of your other posts and found your old comment regarding a PM1340 lathe: 


szenieh said:


> I am trying to figure out what the calculation is. It is not the reciprocal of the TPI. I seem to be missing a ratio of some sort to get from the TPI to the feed rate. Can you help?


If you are interested in TPI and Feed rates for your 1340 you might want to check out the spread sheet tool I spent quite a bit of time building.  I actually works for any lathe that I have seen by setting up a template for the particular lathe.  However, I already did this for my 1440 and the 1340 and a few other similar lathes.  From this template the excel VBA macros will generate a table of ALL possible TPI, Feed, x-Feed rates plus the metric versions.  You can add or remove external gears that you might have or not.  For my 1440 with the supplied external gears there turns out to be over 6000 combinations and so a lot of TPI and feed values.  Anyway, these all appear in a spread sheet table.  I also supplied macros to search as well as sort the table etc.  You can even search with wild cards so that if the TPI value you are after cannot be exactly made you can see how close you can get....  Anyway, if you have seen my posting then maybe you have already tried out the spread sheet. 








						TPI Feeds X-Feeds: Generalized Excel file for your Lathe
					

TPI Feeds X-Feeds: Generalized Excel file for your Lathe  Hi Folks,  My PM1440GT lathe manual only showed a few of the possible threading values and it appeared to me that the Feed rates were incorrect.  They were.   Hence, I set about to figure out what all possible TPI could be achieved via...




					www.hobby-machinist.com
				




I am not getting much feed back on the excel tool and would like some so if you try it out please let me know what you think.

Now, wrt to the 940M base plate.    I am afraid I did this back in 2016-17 time frame and the only cad I had at the time was Microsoft VISIO, which was only 2D.  Do you have access to Visio? If so I could send the drawing.  For now I will just generate a pdf file of the over view page for you.    Since all I was doing was drilling lots of holes plus tapping I did not need 3-D.   Since I was moving the mill into my basement, I took 4 bar stock (two widths) of about 3/8 thickness steel and laid them out on a square such that the ends overlapped.  I then drilled lots of holes to mount to.  At the corners I drilled the holes for the casters and these then both held the casters and held the four plates together.  "These were all 1/4-20 tapped straight through so that the bolts were essentially flush where they were protruding out.    Of course I drilled other holes as well.  I was moving the mill into my basement, so I let this "dolly" do double duty.  I drilled extra holes and tapped them so that I could first mount the mill directly to the dolly and bring it in.  Then I took this off and them mounted the dolly to the mill stand before placing the mill on the mill stand.  Since the mill and the mill stand do not have the same foot print there are a double set of drilled and tapped holes in the dolly.  The ones that were used with the mill are no longer being used.  This required that I move the casters around so instead of 4 tapped holes for each caster there were 8 etc....  So this was my first CNC program to drill all of these holes.  Of course the whole base plate would not fit on the mill table at one time so I did each of the 4 pieces of metal separately and let the CNC get the holes perfectly placed!

Anyway, a pdf file is attached. 

This is not rocket science and your sketches look good.  However, I think that ptrotter's approach is far simpler than either of ours.  One big plate that sticks out on the sides like your design to accommodate the casters.  I think he used 1/2 plate steel.  Had them, where he purchased the steel, cut the OD via plasma an had them also cut out the center to eliminate weight.  He then drilled holes, but he told me that as good as the plasma cuts were he probably would have them drill the holes with the plasma cutter as well. 

Good luck

Dave L.

PS.  I am assuming that you got this about the same time I purchased mine.  Have you had any problems with the head being too heavy for the small z-axis motor to hold it up when the power is off?  Unless I over tighten the gib mine walks down until the cutting tool or head rests on the table etc.  Not good as it also looses the CAD position.


----------



## szenieh

B2 said:


> Hi Salah,     Are you related to Sal_the_Man who I was working with on this string some time ago?
> 
> Nice photos and CAD sketches.  Did you repaint the base.  Mine is green! I will come back to the 940 base plate and casters, but  I was curious about when you got your 940M-CNC so I looked at some of your other posts and found your old comment regarding a PM1340 lathe:
> 
> If you are interested in TPI and Feed rates for your 1340 you might want to check out the spread sheet tool I spent quite a bit of time building.  I actually works for any lathe that I have seen by setting up a template for the particular lathe.  However, I already did this for my 1440 and the 1340 and a few other similar lathes.  From this template the excel VBA macros will generate a table of ALL possible TPI, Feed, x-Feed rates plus the metric versions.  You can add or remove external gears that you might have or not.  For my 1440 with the supplied external gears there turns out to be over 6000 combinations and so a lot of TPI and feed values.  Anyway, these all appear in a spread sheet table.  I also supplied macros to search as well as sort the table etc.  You can even search with wild cards so that if the TPI value you are after cannot be exactly made you can see how close you can get....  Anyway, if you have seen my posting then maybe you have already tried out the spread sheet.
> 
> 
> 
> 
> 
> 
> 
> 
> TPI Feeds X-Feeds: Generalized Excel file for your Lathe
> 
> 
> TPI Feeds X-Feeds: Generalized Excel file for your Lathe  Hi Folks,  My PM1440GT lathe manual only showed a few of the possible threading values and it appeared to me that the Feed rates were incorrect.  They were.   Hence, I set about to figure out what all possible TPI could be achieved via...
> 
> 
> 
> 
> www.hobby-machinist.com
> 
> 
> 
> 
> 
> I am not getting much feed back on the excel tool and would like some so if you try it out please let me know what you think.
> 
> Now, wrt to the 940M base plate.    I am afraid I did this back in 2016-17 time frame and the only cad I had at the time was Microsoft VISIO, which was only 2D.  Do you have access to Visio? If so I could send the drawing.  For now I will just generate a pdf file of the over view page for you.    Since all I was doing was drilling lots of holes plus tapping I did not need 3-D.   Since I was moving the mill into my basement, I took 4 bar stock (two widths) of about 3/8 thickness steel and laid them out on a square such that the ends overlapped.  I then drilled lots of holes to mount to.  At the corners I drilled the holes for the casters and these then both held the casters and held the four plates together.  "These were all 1/4-20 tapped straight through so that the bolts were essentially flush where they were protruding out.    Of course I drilled other holes as well.  I was moving the mill into my basement, so I let this "dolly" do double duty.  I drilled extra holes and tapped them so that I could first mount the mill directly to the dolly and bring it in.  Then I took this off and them mounted the dolly to the mill stand before placing the mill on the mill stand.  Since the mill and the mill stand do not have the same foot print there are a double set of drilled and tapped holes in the dolly.  The ones that were used with the mill are no longer being used.  This required that I move the casters around so instead of 4 tapped holes for each caster there were 8 etc....  So this was my first CNC program to drill all of these holes.  Of course the whole base plate would not fit on the mill table at one time so I did each of the 4 pieces of metal separately and let the CNC get the holes perfectly placed!
> 
> Anyway, a pdf file is attached.
> 
> This is not rocket science and your sketches look good.  However, I think that ptrotter's approach is far simpler than either of ours.  One big plate that sticks out on the sides like your design to accommodate the casters.  I think he used 1/2 plate steel.  Had them, where he purchased the steel, cut the OD via plasma an had them also cut out the center to eliminate weight.  He then drilled holes, but he told me that as good as the plasma cuts were he probably would have them drill the holes with the plasma cutter as well.
> 
> Good luck
> 
> Dave L.
> 
> PS.  I am assuming that you got this about the same time I purchased mine.  Have you had any problems with the head being too heavy for the small z-axis motor to hold it up when the power is off?  Unless I over tighten the gib mine walks down until the cutting tool or head rests on the table etc.  Not good as it also looses the CAD position.


Hello Dave,

No, I am not related to Sal-the-Man. Now you got me curious about this thread and I intend to read it all from the begining.

I got my PM940 CNC in 2018. I did have the problem of the head moving down on its own without power and I also felt the z-axis motor is underpowered. So, I changed it to a higher torque one. I think this machine will benefit from a counter-weight or a strut balancer as the head is quite heavy. I did many fixes: changed the controller to a centroid, I completely rebuilt the head gearbox, and rewired the cabinet. I have designed a tooling quick-change system similar to Tomarch's but I have not completed all the parts for it. Right now, I want to move the machine to a different location and build a full enclosure as I intend to run flood coolant.

At some point, I will do a write up on this machine and will post it here. I will let you know when this happen.

Thank you for sharing your ideas and the drawing. I do not have visio, but the pdf you provided gave me a good idea of what you did. I understand it.

I am very interested in the TPI calculator. I will for sure take a look and will try to use it. I will send you feedback once I do. Tomorrow, I will start reading your thread and will post some updates as I start the drilling and tapping of my contraption.

Thanks again for taking the time to explain what you did and for sharing your work.

Salah
P.S. I did repaint the base as I hated the blue color it came with.


----------



## B2

Hi Salah,


szenieh said:


> I intend to run flood coolant


I did that when I made the caster mounts for my PM1440GT.  It was messy, but I built a plexiglass box around the table and the vice and attached it to the front and the back of the vice while resting on the table.  I then attached adjustable cardboard, via bolts, at the front, back and  ends to allow me to run it right up to the lowest mill head position I was going to use to prevent over spray.     I lined the box with heavy Al foil to cause the oil to drain on to table to then drain back to the coolant pump.  It all worked ok and the mess was pretty much contained.  I have my equipment in the basement of a 1930s house and put all the metal working equipment in one small room.  One of the advantages of having the mill on casters is that I could roll it out.  I then put down rubber, bathroom shower rubber which you can get in 6 or 8 foot widths.   This protects the unsealed concrete a bit.  Then I put down big pieces of scrap card board to catch any drips..... the 940 drips from a lot of places anyway.  The thought was that when the cardboard got dirty I would just switch it out.  However, ti have found that while it has a few stains for the most part it does not get to dirty.  

I had planned on doing the same for my lathe, but after doing my VFD conversion (https://www.hobby-machinist.com/thr...tronic-components-pm1440gt-vfd-3-phase.95058/) I have gotten busy with other projects and have hardly spent any time doing metal working.    I spent too long on the TPI Excel workbook then got busy with non-HM topics!  

What motor did you purchase for the Z-axis.  I suppose you had to change the amplifier from the stock that came with the factory CNC, but maybe you already had done so when you did the conversion?  

I will be interested in what you might come up with for supporting the 940M head.  I went through a number of concepts, but never built any of them.  Getting some of the weight off I think would also improve the z-axis performance in terms of head knod and backlash.  I slowly came to the conclusion that the geared head is so heavy that it actually causes flexture in the vertical way width!   So I started to counter balance with weights or springs (coil spring was the best approach, but these all effectively add more weight on the vertical column), then the air gas spring/struts concept but I did not figure out a way to fasten them nor did I find any that were long enough. (The pushing struts are available in longer lengths than are the pulling versions.) I tried out both concepts of pushing and pulling struts, but never liked my designs.  My more recent concept is to use two pushing struts in series, a pair on each side for a total of 4.  One goes from the mill base to a custom machined part that fits on the ways and lifts/slides the part along the way as the head goes up and down.  The other, goes from the machined part on the way to the center of gravity on the head at an angle.  At the head's lowest position both are compressed.  As the head is lifted the strut going from the way to the head would first expand to lift the head and to keep the head  from torquing on the ways.  When it reached its maximum extension then the second strut takes over to lift the custom part which is mounted on the ways.   This would all seem to fit on the mill and would not require some contraption over the top for a counter balance approach.  It should work, but would it be stable or have its own problems?  TBD.

One has more projects than he can get done.  I also wanted to facilitate a power tap system.  For what I do with the mill this would be more important to me than other tool changing systems.  I purchased the 4th axis CNC and find I do not use it much so I was thinking about using it on the spindle for power tapping.  It would require some custom G code.  

Oh well, back to my work projects.  

Dave L.


----------



## szenieh

B2 said:


> Hi Salah,
> 
> I did that when I made the caster mounts for my PM1440GT.  It was messy, but I built a plexiglass box around the table and the vice and attached it to the front and the back of the vice while resting on the table.  I then attached adjustable cardboard, via bolts, at the front, back and  ends to allow me to run it right up to the lowest mill head position I was going to use to prevent over spray.     I lined the box with heavy Al foil to cause the oil to drain on to table to then drain back to the coolant pump.  It all worked ok and the mess was pretty much contained.  I have my equipment in the basement of a 1930s house and put all the metal working equipment in one small room.  One of the advantages of having the mill on casters is that I could roll it out.  I then put down rubber, bathroom shower rubber which you can get in 6 or 8 foot widths.   This protects the unsealed concrete a bit.  Then I put down big pieces of scrap card board to catch any drips..... the 940 drips from a lot of places anyway.  The thought was that when the cardboard got dirty I would just switch it out.  However, ti have found that while it has a few stains for the most part it does not get to dirty.
> 
> I had planned on doing the same for my lathe, but after doing my VFD conversion (https://www.hobby-machinist.com/thr...tronic-components-pm1440gt-vfd-3-phase.95058/) I have gotten busy with other projects and have hardly spent any time doing metal working.    I spent too long on the TPI Excel workbook then got busy with non-HM topics!
> 
> What motor did you purchase for the Z-axis.  I suppose you had to change the amplifier from the stock that came with the factory CNC, but maybe you already had done so when you did the conversion?
> 
> I will be interested in what you might come up with for supporting the 940M head.  I went through a number of concepts, but never built any of them.  Getting some of the weight off I think would also improve the z-axis performance in terms of head knod and backlash.  I slowly came to the conclusion that the geared head is so heavy that it actually causes flexture in the vertical way width!   So I started to counter balance with weights or springs (coil spring was the best approach, but these all effectively add more weight on the vertical column), then the air gas spring/struts concept but I did not figure out a way to fasten them nor did I find any that were long enough. (The pushing struts are available in longer lengths than are the pulling versions.) I tried out both concepts of pushing and pulling struts, but never liked my designs.  My more recent concept is to use two pushing struts in series, a pair on each side for a total of 4.  One goes from the mill base to a custom machined part that fits on the ways and lifts/slides the part along the way as the head goes up and down.  The other, goes from the machined part on the way to the center of gravity on the head at an angle.  At the head's lowest position both are compressed.  As the head is lifted the strut going from the way to the head would first expand to lift the head and to keep the head  from torquing on the ways.  When it reached its maximum extension then the second strut takes over to lift the custom part which is mounted on the ways.   This would all seem to fit on the mill and would not require some contraption over the top for a counter balance approach.  It should work, but would it be stable or have its own problems?  TBD.
> 
> One has more projects than he can get done.  I also wanted to facilitate a power tap system.  For what I do with the mill this would be more important to me than other tool changing systems.  I purchased the 4th axis CNC and find I do not use it much so I was thinking about using it on the spindle for power tapping.  It would require some custom G code.
> 
> Oh well, back to my work projects.
> 
> Dave L.


I will prepare a write-up that will answer your questions shortly.  To quickly answer your question on the z-axis motor replacement, it is:
1700 oz-in, 86HS155-4208, Nema 34. I am also attaching a spec sheet. I did not change the drivers. The LeadShine drivers are really good. I had to change the setting for the z-axis driver to go to maximum current output- few dip switch adjustments. I am also attaching a pdf specs for the drivers if you don't have that.


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