Ok I need a little help.
I have Mach3, I  use it for my lathe and my mill with no issues. steps per are calculated and are acruate with out using the calibration utillity.

I just built a 4 x 4 plasma table using 20 pitch rack, meshing pinion is 30 tooth, pinion pulley is L timing belt 24 tooth. stepper pulley is 16 tooth.

Now because the rack and pinion are spring loaded there is no clearance, so calculations will not be accruate.

Now I have used the Calibration utillty and I get something like 637.************ for steps per. I used a linear scale attached to the axis and calibrated it to 4" and read it to .### 3 desimal places.

Now when I enter G0 X1 in the MDI the dro will go to something like .9995, or some other irrational number.

Is this normal?

None of my other profiles do this. Did I miss something?

Please Help

It could be due to your steps/unit not adding up to exactly 1. What is your exact steps/unit?

I am at work, I will have to get it later. I will never =1 becaues the full mesh does not follow the theroetical Pitch circle. Right?

I will let you know latter. Maybe I can round it off?

Ok home now

steps per for X and Y which both have same mechanical setup are

637.385782

Any ideas?

When you tell Mach3 to move 1inch, it moves 637 steps, which is .99939

638 steps is 1.00096

What's happening is that mach is getting as close to 1 as it can, given you're steps/ unit.

OK I will live with it.

I cut some polycabanate test pcs that was within .005 to .007 with a crapy Roybi router.


Thanks for you input.