arduino grbl controller
x y axis similar to the cheap langmuir type of plasma table.
using 9mm timing belt mounted to both corners/ends of the table the motor is mounted on the x/gantry the belt runs from one side of table then under a pulley on the gantry and up to the motor gear then back down to another pulley then over to the other table corner.
y axis is about 6' long
if I put a ruler on the table in y direction and start my torch tip moving over the ruler from zero toward 10" I can alter my steps per mm to correctly move from 0 to 10".
If I then move from 10 to 20" mark I'm 1/8" short. move to 30" mark I'm 1/4 short.
had found conversations that said:
check belt tension - since I've no idea the best tension I tried various tensions and same results.
check voltage - checked and supply is providing 23.9v the nema 23 stepper requires 24v.
belt can be stretched unevenly - to see if it was an uneven type of problem I switched the belt direction figuring if it was uneven then I would see the opposite problem.. but no.. same problem.
Also note that I can tell it to go to zero from any of those points and it correctly goes to zero every time. So I wouldn't think any steps are being missed.
Maybe someone knows something I'm not testing to get a little further.
Oh I also switched the stepper motor out and no difference.