I just completed setting up a new cnc machine it uses a tp8x8 p2 leadscrews. I configured Mach3 and ran a sample. Everything functioned except sample was a 1x1" block .625 deep. It measures 1.25 x 1.25 . Where did I go wrong?

Hi,
you have calculated the <steps per unit> value incorrectly.

You say you have 8TPI leadscrews, are they two start?
Are your steppers direct coupled to the lead screw or do you have a gear or belt reduction?
What microstepping regime are you using?

With these numbers it possiblt to calculate the required <steps per unit>.

Craig

Thanks for the quick response. The leadscrews are coupled to nema 23 motors and they are 2 start. I have no idea what microstep regime is?

Hi,

I have no idea what microstep regime is?

If you don't know you need to find out. How did you set the <steps per unit> value in Mach motor tuning pages WITHOUT
knowing?

The microstepping regime is the number of pulses required to cause the stepper to rotate 1 turn. Most normal two phase steppers
require 200 pulses, this is called fullstep. If the drive is set to half step it would require 400 pulses. 1/4 step 800 pluses and so on.
A good middle of the road setting is 8 microsteps per fullstep or 1600 pulses per rev. You need to set the microswitches on your drive
to do that.

Craig

Multiply your current steps per by 0.8 and try that.