direct drive motors, so no gear reduction.
1.8 degree motors = 200 steps per rev.
10x microstepping = 2000 steps per rev.
8tpi 2 start screws (4tpi effective) = 8000 steps per rev.
This is the part I'm not sure of.
I want to run metric programs and DRO's, so divide 8000 by 25.4 ?
I set steps per in the mach motor screen to 314.96
EDIT: I also thought maybe it was the rounding, and set it to 314.96062 with the same result.
When I run from zero, to 700 mm, the measurement I get is approximately 1mm farther than it should be.
Am I missing something here?
Swiped from another post, but modified to fit my numbers:
4 TPI = 1/4 = 0.25 inch pitch 0.25 x 25.4 = 6.35mm pitch
200 steps per rev x 10 micro steps = 2000 steps per rev
1 rev = 6.35mm so 2000/6.35 = 314.96062 steps per mm.
It would appear my way of calculating it came up right too?