Hi
I have retrofitted my lathe and all is fine. Simple x and z cuts seem very accurate. But...I have hand written code to produce a pawn shape (No that was spelt correctly!) I am using a series of subroutines with G2 and G3 cuts using the I K system. My all dimensions are in mm to 4 decimal places. After 30 loops the position has drifted significantly by around 0.5mm per axis. What am I doing wrong??
I am on Servo motors with 2000 resolution encoders.
I have adjusted Gibs, backlash in the belts, the ballscrews seem fine.
I have slowed down velocity and acceleration to a fraction of what the servos can cope with.
I have broken each arc down into a separate subroutine in order that the errors do not add up - minor improvement
I have broken arcs that intersect axis lines (causing the motors to reverse) into separate sections.
I could get around the error multiplication by resetting zeros before a final cut but that seems very crude.
Are arc moves generally inaccurate or is it me?