Pm-940m-cnc (pre-assembled)

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
 
@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!
 
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
 
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.
 
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
 
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
 
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
 
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
 
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:

PZ
 
@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
 
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