"I ran another long program last night. The Y axis is drifting. Its not the heat in the control cabnet and the motor is warm but not hot. I lost about .2" in 3000 lines of code. I'm not familiar with Mach3. Could this be backlash adding up?
i_r_ "
IR,
I'd check your calibration of that axis. It sounds to me like you don't have the steps per inch calibrated accurately enough..
Mach3 has a function - under the Settings Tab, -> Steps Per Unit
Where you tell it to move a certain distance, and then input what you actually moved.. Put a test indicator on a 1-2-3 block with another 1-2-3 block standing vertically - to make a sort of horizontal "L" shape..
always move in the same direction -and never reverse direction - to take backlash out of the equation.. (ok you can do the same thing with a calculator, but why when Mach3 will do the math for you...)
Note: If you're using a cheap 1-2-3 block -it may actually be off as much 0.005 in. - so use a known calibration gage block.. make sure you align it .. and take your time..
Just my $0.0015 worth..
Joe