My sizes are out

[Desertboy]

Sounds like your "steps per unit" calculations have gone a bit wrong. Can you recheck, or post all relevant data here so someone else can check your working?

The other way of doing it is starting with a good first guess - which you have - and then modifying the "steps per" based on the results of a calibration run. Personally, if my calculated value were out by more than a tiny amount then I reckon something's wrong - my calculation or a machine error. Slipping coupling, missing steps, or whatever. However, others take the more empirical approach. In short - keep tweaking until you get the right answer! Mach3 actually has a calibration capability built-in but don't know about your controller.

On the ddscv it's steps per mm

I have 8 microsteps
so 8*200/10 (1610's) for X&Y 160
320 for Z (1605)

Just double checked this is definitely what they are set to.

AM882 has fault protection it should detect missing steps and estop and I swapped all the couplings for these style, I bought the chunkier ones.



so they're rated twice the nm of the motors.

2 4nm in the bottom and 3nm on the gantry, PSU is 70v and 1kva.

Will try and cut 3 holes at 33mm, 66mm and 99mm see if the error scales perfectly I tried cutting from speed of 0.5m/min to 10m/min exactly the same results.

Carved a lot of 3d stuff on this machine and that's machining for hours not seeing issues there or sign making never noticed the size was wrong until I tried to make an adapter and it didn't fit.

Both X&Y are out by the same amount not sure about the Z.