Originally Posted by
arsenix
The machine still seems to do this periodically. It doesn't seem to impact surface finish. The Y axis also shudders a bit. I wonder if the P gains are just tuned too high? I have been working on a 4th axis addition to this machine as well, and one thing I noticed when looking at the PWM command to the A axis was that even with a static error (axis stationary, commanded position stationary) the PWM signal has periodic digital noise spikes on it. This does not make a lot of sense to me. This machine uses a special "PWMINT" card on the control card, but it isn't clear what the interface to this card looks like. Maybe it is analog and there is noise getting in here? Unclear. This issue still irritates me but the machine seems to run parts fine with it. It mostly concerns me it might get worse.