So I’ve had my X-Carve for about 4 years now and moved to a new shop within the last year (I had to disassemble my rig in the process.) Since I had already taken it apart, I decided to rebuild the X-carriage with the new version and add a drag chain. I have a 1000mm with a Dewalt spindle and Nema 17 steppers. Recently, I’ve been having trouble honing in circular cuts.
To troubleshoot, I took a ruler and starting at zero, moved in 1 inch increments until I got to 20". As you can see, the position is off by 1/8". Moving back to the zero point of the ruler results in it returning to the exact home position. The Y axis is spot on.
Based on what you are reporting yes your circles would not be round.
A 20 inch circle would be 20" tall but only 19 7/8" wide.
Does this match the errors you have been seeing?
Whatever step/mm value you have the bit will always come back to the same spot if you jog equal amount in and out.
You need to recalulate your step/mm value for X which is parameter $100. Lets say its 40.
Take out your ruler, do a very short X+ jog (to take out backlash) and then a single long jog in same direction and measure the travelled distance of the single long jog.
Say you get 19 1/2" of travel for that 20" jog.
Math is:
Current GRBL value / actual travel * commanded travel
40 / 19,5 * 20 = 41.02