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Pm-940m-cnc (pre-assembled)

cut2cut

Active Member
Active Member
#31
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.

IMG_0795.jpeg

Cheers,

Jake
 

phazertwo

Active Member
Active Member
#32
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
 

cut2cut

Active Member
Active Member
#33
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

IMG_0969.JPG IMG_0970.JPG
 
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cut2cut

Active Member
Active Member
#34
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

IMG_0998.JPG
 
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cut2cut

Active Member
Active Member
#35
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

IMG_0997.JPG
 
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phazertwo

Active Member
Active Member
#36
Well mine showed up on Wednesday, got it home and on the stand all in one night. Got to play around with it for and hour or so tonight, which means I got to jog the table around a bit.

The machine seems very nice. The ways are beyond what I expected as is the table. I got the cheep 6" vice with the mill, thinking that I will upgrade to a Shars later, but at this point I am so impressed with the quality of the vice I feel like I may not upgrade... The cabinet is wired very cleanly, all wires actually have ferrules and wire numbers on them.

The only thing I see so far that I am disappointing in is the manual for the nMotion controller. I would say it's about 50% effective, but I also consider myself well above average at reading "translated Chinese".

I added a pic of the machine and cabinet below for your view pleasure.
PZ


 

cut2cut

Active Member
Active Member
#37
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

Active Member
Active Member
#38
IMG_1010.JPG 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.
 

rodjava

Steel
Registered Member
#41
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?
 

rodjava

Steel
Registered Member
#42
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
 

cut2cut

Active Member
Active Member
#43
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
 

cut2cut

Active Member
Active Member
#44
IMG_1070.JPG 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
 

cut2cut

Active Member
Active Member
#46
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

Iron
Registered Member
#47
(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.
 

cut2cut

Active Member
Active Member
#48
.....
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

Active Member
Active Member
#49
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

Active Member
Active Member
#50
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
 

Attachments

phazertwo

Active Member
Active Member
#51
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
 
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cut2cut

Active Member
Active Member
#53
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
 

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cut2cut

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Active Member
#54
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

IMG_0810.jpg
 

cut2cut

Active Member
Active Member
#55
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.
 

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phazertwo

Active Member
Active Member
#56
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
 

phazertwo

Active Member
Active Member
#58
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

Active Member
Active Member
#59
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

Steel
Registered Member
#60
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