Hello all,
Starting to get my lathe alive and running parts, and having an issue. I seem to be losing position occasionally. I played with the PID settings on the Granite servo drive, and got my following error limit down to 15 counts (20,000 per inch), so I think that should run pretty tight. So I'm trying to run multiple pieces. I'm using 5 tools: face/turn, center drill, drill, cutoff, and barpull. The facing and turning seems to go fine, but occasionally the shoulder I'm turning comes up .005-.010" too long or too short. The bigger problem is when cutting off the part, it can be .05-.100" too long or short. As if Mach is losing position during the tool changes or rapid moves. This doesn't happen every time. The shoulder is off in 1 part in about 10, and the overall length has been of maybe 1 part in 5.
I've tried rehoming the Z axsis, and it generally ends up way off (.100-.200) after doing so.
So where am I losing counts? I guess I need help understanding the failure modes that are possible.
Thanks for reading!
Kevin