Help with setting Steps per Unit

[EngraverGar]

Here is my hardware;
Old Meistergram engraving machine built like a tank.
Old Dell running WinXP
Vexta PH268-21, 5V, 1.5A, 1.8*, 125 Oz torque. Used on X and Y.
Sain Smart TB6560 BOB, ST330 Motor driver. (I know, but the motors run fairly well using these).

Setup in Mach3. Driver test passed, excellent.
Motors tuned. In both 8 step and 16 step. Running smooth and reasonably fast. No weird noise. I have set torque and decay on all the different setting and found the best for each.
The current has been set at 1.5A and 1.0A with no change.
My figures came out 1600 steps for 8 step micro and 3200 steps for 16 step micro. (200 x 8 =1600 and 200 X 16=3200) I have also tried putting a guesstimate of 2000 steps and tuned accordingly.
Units are set in inches. All of this testing and changes have taken more hours than i can recall.

So here is the problem.
When i go into setting and use the Wizard for setting steps per unit it has not come close to the unit in inches. I have used 1", 4", and 12". the travel is like a 1/4" to 3/8. When i accept the recommended steps from the Wizard
and run the setup again I get a very similar distance. maybe 1/32 longer. The Wizard has adjusted the steps up to over 300K and no change and not close to inch units.

So where have i made the error in setup because i know 99.9% of the problems are operator error. Are my step figures correct.
The only thing i haven't done is reload Mach3. The reason i haven't reloaded is i have set up a Dyna 2400 milling machine with Gecko drives and it runs fine with this version of Mach. Oh and the machine is not connected to the internet so it is not polluted, but makes it more difficult to update.

As always any help will be greatly appreciated and i know some of you human Wizards will be able to guide me through!

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[dazp1976]

Setup in Mach3. Driver test passed, excellent.
Motors tuned. In both 8 step and 16 step. Running smooth and reasonably fast. No weird noise. I have set torque and decay on all the different setting and found the best for each.
The current has been set at 1.5A and 1.0A with no change.
My figures came out 1600 steps for 8 step micro and 3200 steps for 16 step micro. (200 x 8 =1600 and 200 X 16=3200) I have also tried putting a guesstimate of 2000 steps and tuned accordingly.
Units are set in inches. All of this testing and changes have taken more hours than i can recall.

Are you forgetting to add your screw pitch to your math?

[awerby]

If you're telling it to move 12 inches and it moves about 3/8", that sounds like inch/mm confusion. What happens when you go into MDI and give it a G20, then a directional move in inches?

[peteeng]

Hi Dazp - You don't need to understand the math, if you tell it to move 12" and it moves 3/8" then increase the steps/unit accordingly. 12/(3/8) = 32x so whatever number you are using for the steps/unit x32 and redo. Then check and adjust again etc. Peter

[dazp1976]

Hi Dazp - You don't need to understand the math, if you tell it to move 12" and it moves 3/8" then increase the steps/unit accordingly. 12/(3/8) = 32x so whatever number you are using for the steps/unit x32 and redo. Then check and adjust again etc. Peter

Fair enough.
Has he set native units to inch?

[peteeng]

Hi Dapz sorry I meant to address to Engraver...