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Re: Southwest Industries Prototrak DPM conversion

Posted: Mon Jul 17, 2017 7:19 pm
by martyscncgarage
Best of luck, I know what it's like to have multiple irons in the fire. Hope the garage expansion yields more shop space.

When you sent your servo in, did they happen to tune it to get baseline PID numbers? You might check with Scott?
Also, CNC12 is on the horizon, you might ask about the upgrade should you get CNC11 now so you can get your machine through the rest of the testing/build.

Marty

Re: Southwest Industries Prototrak DPM conversion

Posted: Mon Jul 31, 2017 8:47 pm
by CRM
Marty, thanks for the heads up on CNC12. I've waited 6 years, a little longer isn't going to kill me. This retrofit is happening in fits and starts, usually during the winter. Too much to get done outside in the 17 days of summer we have in Minnesota ;)
As to the PID baseline numbers, I don't know. But I'll be sure to inquire beforehand when I'm getting ready for the remote support session.
The garage addition is on, but doors have to be built and hung (the entire west endwall is door) and the landscaping needs to be finished. But yes, it should allow me to move some stuff out of the climate controlled part and free up some badly needed space.
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Re: Southwest Industries Prototrak DPM conversion

Posted: Mon Jul 31, 2017 9:30 pm
by martyscncgarage
Nice! More room for machines!
Do check with Scott to see if they did get baseline PID numbers when they had it. Post pics 9n your progress.
Marty

Re: Southwest Industries Prototrak DPM conversion

Posted: Wed Aug 16, 2017 4:41 pm
by CRM
Man, when it rains, it pours. The final push to wrap this conversion up is going to have to wait a while longer. Had a water pipe break in the house. :cry: Right now, the priority is a functional kitchen and Air Conditioning again.
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Re: Southwest Industries Prototrak DPM conversion

Posted: Sat Aug 19, 2017 5:44 pm
by diycncscott
Bummer. I'd get the AC working first. You can always eat out but I think the AC will make the kitchen work much more bearable.

Re: Southwest Industries Prototrak DPM conversion

Posted: Mon Aug 28, 2017 9:22 pm
by martyscncgarage
Boy that sux. I hope you get through it ok. You'll be back at the conversion before too long.
Best of luck to you.
Marty

Re: Southwest Industries Prototrak DPM conversion

Posted: Fri Nov 29, 2019 3:18 am
by CRM
I just read through this entire thread again. Embarrassed that I started in 2011 and have not fully commissioned the machine :( I have access to a Haas VF-3SS at my day job, so it is easy to let this one slide. The last time I made a big push (in 2017) I bought the CNC11 software since my demo time was about 85% used up and got stuck at servo tuning; because of that I haven't done the final linear displacement calibrations. I have used it manually here and there on some simple things though. I am seemingly unable to get my servos tuned to my satisfaction and am wondering if there is a thread somewhere that gives an overview on how to prepare for a teamviewer session (I've never done one before) and any other prep I should do in order to successfully tune the servos remotely?

Re: Southwest Industries Prototrak DPM conversion

Posted: Fri Nov 29, 2019 9:01 am
by martyscncgarage
Did Centroid setup your motors/encoders with the All in One DC? It was my impression that's what they wanted to do so they had the Data for future customers.

Have you tired to run Autotune?

Marty

Re: Southwest Industries Prototrak DPM conversion

Posted: Fri Nov 29, 2019 12:04 pm
by CRM
Marty,
I did send my servos off to Scott, who had offered to do the labor to fit new encoders in exchange for doing some R & D testing. Remember, this was 8 years ago. It is MY fault this project has taken so long; Centroid/AjaxCNC has always been prompt with responses to my queries. That said, I don't remember receiving any baseline tuning parameter info, nor did I realize any would be needed at that point in the conversion so it never occurred for me to ask. If you are familiar with how SWI designed their CNC control, they integrate the servo drive and motor into one unit, sending step and direction signals from the PC CNC control and 120 VAC power to each drive attached to the motor. At the time I thought Scott was only trying to determine if it was viable to separate the Magnetek motor from the drive to be used with the ALLIN1DC board. In hindsight, it makes total sense he was also running tuning tests.

Thinking on this a minute brings a couple of questions to mind: Would those tuning parameters be the same for a motor NOT under load (installed and connected to the ballscrew) as it would be sitting on the bench?

When I first discussed this retrofit with Scott, he indicated that I would need a step down transformer, given the ratings on the motor nameplate; and I assume that is how he would have tested the motors with the ALLIN1DC. After I completed the retrofit to the point I could put the machine under power, I determined that I could safely remove the step down transformer and direct rectify, based on a comparison of before and after rapid travel speeds and an examination of the SWI drive board that was originally used. Would the change in motor voltage affect the tuning parameters? That is, would Scott's data (if it exists) still be valid or useful? If so, how would I go about getting that data to help me try to tune the servos?

It may also be important to note that I had an early production ALLIN1DC with the lower voltage caps, and powered it up with direct rectified current (which tripped the mains breaker) before being informed the caps needed to be replaced with higher voltage rated ones (as was mentioned earlier in this thread). It didn't appear any components on the board were damaged, and everything functions as it should as far as I an tell, but I guess I have to ask if there could be any connection between that and me not being able to tune the noise out of the servos when they are holding still?

I did run Autotune. When the servos are being commanded to move, the following error is pretty decent (for the class of machine I have) according to the built in oscilloscope. My issue is when the servos are holding steady position, there is a high frequency "ringing" from them that is quite noticeable. When I place my hand on an axis handwheel, I can feel the vibration as it oscillates. Not at a magnitude great enough to show up in the DRO, but I can definitely hear and feel it in a way that didn't exist with the original control.

I will be having some time off work in a couple weeks and am hoping to be able to spend some time to bring this project across the finish line. Would there be any value in taking some video of the machine as I jog it? I am hoping the audio will come through so people can hear what I hear and understand what I mean. I could also capture the screen when I have the tuning page up to show the servo response to movement commands. It's been a year and a half since I've done any of this, so I need to re-familiarize myself.

Re: Southwest Industries Prototrak DPM conversion

Posted: Fri Nov 29, 2019 12:12 pm
by martyscncgarage
We need to see motor nameplate voltage and current ratings. If Scott said you needed the step down transformer then you probably needed it. Unless your motors are rated for 180vdc.

Scott would have lost likely bfitted the encoders and used one of their power supplies of the correct DC voltage, and tuned the motors the best he could.

I'd be immediately wary of the max motor terminal voltage vs. what you are supplying to them. Post a fresh report from the control as well. We can look at PID values. I assume Scott sent you a report to use as a baseline for your mill?