My steppers are 1.8 degrees per step that should be 200 steps for a full turn. The ball screws have a 5mm pitch that should give me 40 steps for 1mm with micro stepping that should make it 400 steps. Do's this sound right?

Also when I wired the machine I was following a you tube video and they were not using the home switches  just the 6 end stop switches. They said you could use the end switches as home switched but they never showed how to do this. Now it  may tell me how to do this in the Mach3 user guide but reading pdf's on the computer hurts my eyes after awhile. If you know what page it's on please tell me. If not do I rewire the 3 switches for home ( Forward. left  and up) and leave other switches as end stops. Or do I need to wire in new home switches.

Thanks you for your time.

Ron     

 Ok so what is your micro stepping value? 8,16 ?
 as far as the switches of the switches are at what would be the home position. you can use limit switches for both home and limit. you just have to select it in the ports and pins settings.

Thanks for your replay.
I now understand more about my motor drivers ( I didn't receive documentation with the motor drivers) So the steppers having 1.8 degrees per full step and the motor driver having 32 micro steps per motor step with a direct drive ball screw having 5mm single thread pitch that should be 1280 steps for 1mm if  I'm not missing something.

Thanks
  Ron

Hi Ron,
  Your math is spot on.
I got the same as you. That will get you in the ball park. You will then have to calibrate or fine tune each axis using the axis calibration in mach3

You don't have to set microstepping to its maximum - you won't get  the added precision you might expect.  With ballscrews I've found that the calculated resolution is what I get without additional calibration.

Hi,

I got the same as you. That will get you in the ball park. You will then have to calibrate or fine tune each axis using the axis calibration in mach3

No, the calculation should be perfect. There should be no need to tweak it, if you do then that means that you are doing something wrong or the stepper is missing steps.

It is nice to think that microsteppeing improves resolution, but it does not work out that way in practice. There is a rather long a tedious explanation as to why that is case,
it all comes down to diminishing torque between microsteps. In truth most steppers can do no better than half-stepping, ie 400 step/rev.

The principle gain with micro stepping is not resolution but motion smoothness. Astronomers first invented microstepping with steppers mainly to smooth the movement
of their telescopes. At around 8 microstepps per full step is a good compromise. You get the majority of the smoothing that is available, whatever resolution gain you can get
without overly increasing the signalling rate. I would suggest changing your driver switches to either 8, or 10, or 16 microsteps per full step.

The manner of the calculation remains the same.

Craig