Need Help!- Mach3 Problems With Homebuilt Machine

[ltl2007]

Hey guys. My first post!!! So I was hoping to pick your brains and see if anybody can help me out. I have a 4'x6' plasma table I build a while ago, and it has worked flawlessly for about 4 months. A few weeks ago, I went to run a programs and the movement was very jerky, almost like it was missing steps. I ran the "Set Steps Per Unit" option under settings in Mach3. Doing that, it runs PERFECT!!! But if I run a code, or use something like G0 x10.000 from 0.000, it runs like hell. The feedrate isnt overdriven, and I dont know what else to check. any help would be greatly appreciated. Also, i dont know if it helps, my steps per inch are 400, using 5 amp nema 23 steppers, 10 amp driver board, 350 in/min, 50 in/min acceleration. dual motor x axis, single motor y and z.

[blackbeard52]

I know this sounds simple but, What has changed since the initial install? Are you running virus protection, if so remove it. Is the PC on the internet or network? if so remove it. Are you running a screen saver or any cute programs to make it busy? if so remove them and lastly after these have been resolved save the xml file and uninstall Mach3 and restart and then reinstall.....

Bob

[ltl2007]

The only thing that has changed was the power supply, i went from a 30A 12V dedicated, to two ATX computer power supplies. They kept shutting off, so i went back to the 30A. THe computer is a fresh install of XP, with just mach 3 on it, no networking at all. There arent any other programs running in the background. I tried it again tonight, and when I use the set steps per unit command, I can run it 100" back and forth and be within 0.001". The problem is when Im trying to run code, or manually typing in commands. I tried to make a video with my camera tonight, but it didnt come out any good, ill try again tomorrow. It seems like it is trying to overdrive the steppers, and at the same time trying to throttle down. its a very strange issue. Also, i reinstalled mach 3, and tried mach 2, and kcam, and it did the same thing in mach 2, and it wasnt as bad in kcam, since there is no tuning. AHHHHH!!!! And to top it all off I have 300 parts to cut by Wednesday!

[blackbeard52]

Have you done the XP optimization for Mach3?

http://www.machsupport.com/downloads...timization.txt

[Torchhead]

Check the following:

1. Run DriverTest.exe in the MACH folder. The graph should be relatively level with just occasional brief spikes. If you see lots of spikes (like piano keys) or clusters of spikes you need to look to the PC and something running in the background as the problem. Since this ran okay before it is not the PC hardware itself (some MB's don't play well with MACH.

2. If you can't simply jog an axis smoothly check the motor tuning. The Set steps per inch uses a lower step rate VS jogging or running

3. Make sure you have not changed the hardware/environment. Sometimes it's subtle. Having a network card setup then unplugging the cable will cause Windows to poll for a connection and mess with timing.

4. Make sure your core frequency in MACH (opening config window) has not changed from what you had setup. This happpened to me the other day on a servo table we have in production. I cloned a profile and was using it and then it started to fault the drives. It had been setup to the 45Khz freq and the velocity and accel was for that. Somehow it "slipped" back to 25Khz but left the motor tuning the same so it was doing weird stuff.

TOM CAUDLE
www.CandCNC.com.