Using PM-728VT as a Manual Mill After CNC Conversion: Experiences Needed

[7milesup]

If you want to maintain the machine's manual functionality after converting it to CNC, you need to go with servos. The cogging of stepper drives will be a study in frustration if you want precise work.
I own a 2-axis CNC knee mill that has high-end ball screws and servo drives. It is a dream to use in manual mode, being very smooth and precise. My knee mill uses a proprietary CNC control from Southwest Industries. The A.G.E control system is far outdated but it still works for now. My intention is to replace the CNC control this coming winter and add the quill as the 3rd axis.

As far as CAD software, I know a lot of people use FreeCad because of the price. You get what you pay for. I would suggest learning Fusion360, mostly because it does include a post-processor (formerly HSM) and also because it is a more "real" CAD system. As you may know, Fusion is free with some limitations (no rapid travels, only 10 files open at a time, for example). https://www.autodesk.com/products/fusion-360/personal

I plan on converting my mill to either Centroid or LinuxCNC. As you are finding out, properly converting a new mill to CNC is not cheap, and you are certainly not the first to go down this path.

 

[DavidR8]

Following along as I have ambitions to convert my bench mill to CNC.
Far off in the horizon though.

 

[jdsantiagojr]

If you want to maintain the machine's manual functionality after converting it to CNC, you need to go with servos. The cogging of stepper drives will be a study in frustration if you want precise work.
I own a 2-axis CNC knee mill that has high-end ball screws and servo drives. It is a dream to use in manual mode, being very smooth and precise. My knee mill uses a proprietary CNC control from Southwest Industries. The A.G.E control system is far outdated but it still works for now. My intention is to replace the CNC control this coming winter and add the quill as the 3rd axis.

As far as CAD software, I know a lot of people use FreeCad because of the price. You get what you pay for. I would suggest learning Fusion360, mostly because it does include a post-processor (formerly HSM) and also because it is a more "real" CAD system. As you may know, Fusion is free with some limitations (no rapid travels, only 10 files open at a time, for example). https://www.autodesk.com/products/fusion-360/personal

I plan on converting my mill to either Centroid or LinuxCNC. As you are finding out, properly converting a new mill to CNC is not cheap, and you are certainly not the first to go down this path.

It's definitely not cheap. However, it seems like it would still might be a lower cost compared to purchasing something like a Tomarch. I can probably buy things a little at a time and start using the mill as I gather everything I need. I'll probably have to buy the servos and drivers one at a time.

 

[u2fletch]

I have done a few CNC builds/conversions using LinuxCNC with stepper motors and I really like the Mesa Electronics driver boards. Specifically the 7i96S. It connects via Ethernet cable to computer. One machine uses a Raspberry Pi 400 and a touchscreen. Runs very well. I also use an XBox controller as a jog pendant. With some creative code you can get a lot of control of the machine.

Have all the parts ready to convert my PM-940 to CNC. Wanted to run it manual awhile to get familiar with its capabilities. I installed the touchDRO on it and definitely plan on keeping it after the conversion.

 

[jdsantiagojr]

I have done a few CNC builds/conversions using LinuxCNC with stepper motors and I really like the Mesa Electronics driver boards. Specifically the 7i96S. It connects via Ethernet cable to computer. One machine uses a Raspberry Pi 400 and a touchscreen. Runs very well. I also use an XBox controller as a jog pendant. With some creative code you can get a lot of control of the machine.

Have all the parts ready to convert my PM-940 to CNC. Wanted to run it manual awhile to get familiar with its capabilities. I installed the touchDRO on it and definitely plan on keeping it after the conversion.

That's really good to know. I was struggling with the decision to get DRO installed, but I do want to run the machine manually before making the conversion.