how to setup the steps per unit in config->motor tuning

[lucky021]

I got confused here, what I should setup in "steps per": 1600 or 32000?

My unit is "inch", if I setup "steps per" to 1600, it means it takes 1600 steps to make one inch movement, right? but in my system, I use 1600 step/rev (200*8 micro-step) motor and 20 tpi (20 threads per inch) rod, so does it mean I should put 32000 in "steps per"?

To imagine, my motor can be set to 125 micro-step with 25000 step/rev, with 20 tpi rod, the number will be 500000 steps per inch, then the maximum velocity will be only 3, which looks weird? So in my real case, 1600 or 32000?

Thanks.

[Kipper]

Try 32000 then ask it to move 1 unit in the settings tab....then enter that value and try 10 units to get more accuracy.....Or convert to Metric

[dustin1706]

You are correct, the "steps per" is how many motor steps to move one linear inch.

So, 200 steps per motor revolution * 8 microsteps per motor step*20 motor turns per linear inch = 32000 steps per

Provided that the specs on your motors, drivers, and rod are correct, this should be exactly correct.

Mach 3 does have an auto calibration that you can use if you care not sure about any of those specs.

To do a quick check, enter 32000 steps per inch, jog the machine, say 10 inches, and measure the distance it actually moved. This will confirm that it is correct before you start cutting.

Just as a comparison, I have 200 step motors, 10 microstep driver, and 10 tpi acme rod and my Steps per is 20000. My rod is 1/2" diameter and on a ~3ft MDF machine I can run almost 100 ipm before I get any serious whipping.

If you were to set it up for the 125 microstep, you would find the machine to be waaay to slow and there would be no advantage. Unless your machine is rigid/accurate enough to move 1/500000" lol.

[lucky021]

thank you all.