Fault On Machine Axis Reversing

[bill south]

Posted on the Gecko Drive Forum - Posted here for visability!

Hey Guys;
I've just converted my home built router from UHU drives to 320's and I'm having a bit of a problem. When I first started up after the conversion, I was getting faults on all servos at different times during a cutting session. I'm using Mach 3 for control software and NEMA 34 Electrocraft Servos.
To start, I lowered the cutting speed from 120 inch/min to 80 inches and lowered the acceleration to a setting of 8. Still no joy.
After reading everything I could find, I decided to install line drivers on my heds encoders to boost the signal (what has changed with those folks). Still had the same problem after another $50 investment. Prior to this, I added the resistors on channel A and B for all dirves and again No Joy.
When I first set up the drives, I tuned the 320's by adjusting the gain, then the limit until the oscillations stopped. I tweaked the gain several time for maximum performance. I think they are adjusted OK or at least, this tuning procedure worked on my milling machine.
I then repalced the encoders with encoders form digikey (CSI?). Cute little things and didn't break the bank as the us digital encoders did. I also eliminated the line drivers since my cables are fairly short.
Now, I'm back on line but the y axis is still faulting with the speed at 120 and the acceleration at 10. I think I should be able to run at this speed. My computer is a Dell desktop with a parallel port card installed set at a Kernal speed ofr 60000. The computer seems to work fine.
I noticed that I can make the drives fault when I change direction (quick change). Is this caused by too high of an acceleration or too high of a speed? I'll slow everything down if I have to but I've a lot of $$ invested in equipment and hate to be substandard in performance.
Help, I need to get back into business and I'm running low of money and patience.
Best Regards.
Bill