Machsupport Forum

Mach Discussion => General Mach Discussion => Topic started by: millman on August 08, 2015, 12:40:06 PM

Title: ADJUSTING PID SETTINGS FOR SPINDLE CONTROL
Post by: millman on August 08, 2015, 12:40:06 PM

I am  having trouble understanding the PID settings for spindle control.  I am running a 2HP VFD drive and Gecko 540 controller. I have magnetic sensors on my spindle pulleys.  I can get my spindle within 5% of the commanded speed for normal work. But when threading, my cutter gets out of place and begins to wipe out my previous passes.  It seems that the PID is somehow calculating an error each pass and changing the start position of the cutter to compensate for this error in the RPM.  I found that if I manually set the RPM with my laser tach, then plug that value into the Mach 3 threading wizard, it cuts perfectly.  I just don't understand how to adjust the 3 settings in PID to sort this out.