# Steps per um not correct after changing motherboard on laser

Hi Im trying to get my steps per um fixed on a cam five laser with a ruida controller. Ive cut a 1X1 in. square and it is cutting at 1.1875" X 1.1875". My steps are currently at 5.216457 um. What would be the conversion or does the calibrate axis option correct this for me?

The old cross multiply and divide from math should get you in the ballpark.

So:
1.1875 = 5.216457
1.0000 = X

X = 5.216457 / 1.1875
X = 4.392806 um

That made the square cut bigger, closer to 1.4375. So the steps would need to be higher than 5.216457 to make the cut closer to 1 in.

For Ruida controllers the value is um per step (or ‘Step Length’), rather than steps per mm. So you need to multiply the Step Length by 1.1875.

To answer your first question, yes, you can use the Calibrate Axis tool for this. ‘Edit’ > ‘Machine Settings’ > ‘Calibrate Axis’.

I subtracted the two step intervals and added it to the original and it seems to have gotten it very close.

This topic was automatically closed 30 days after the last reply. New replies are no longer allowed.