Hi,
I have a problem that's stumping me on my Kogna/Milltronics machine, I wanted to see if anyone thinks it could be a servo tuning issue. Until today, I had a very intermittent banging sound that only happened using the MPG to jog the X axis (maybe 3-4 times in 2 months). It had never happened when I was really paying attention and I had almost convinced myself it was one of the spring loaded way covers getting stuck and banging back into place. I've used the machine quite a bit with no problems, but only for a couple hours at a time until today (it was also the first day that my shop was kinda hot).
So today I run the machine for about 8 hours, and at the end of the day I hear the banging sound a couple times. I went back to the machine and my program was still running, but while I was watching the X axis visibly jerked, making the banging sound. Maybe 30 seconds later the X axis went into a violent oscillation, and I Estopped the machine. After the machine sat for about half an hour, it took me about 10 minutes of jogging the axis back and forth to reproduce the problem (the jerk/bang, it didn't oscillate again).
My thoughts are: I did the servo tuning with brand new linear rails and trucks, and fresh seals on the ball screw. The system may have had significantly more resistance to motion when I did the servo tuning that it has now when it's fully warmed up, and the X axis has the least mass to move of the 3 axes.
Is it possible or likely that too much gain could cause these symptoms? I revisited the step/response screen, but everything looked the same as when I initially did the servo tuning.