Problems with circles / holes

Hello,

when I'm trying to print, the holes or circles are weirdly off (see picture).

What could cause such behavior?
I already checked, if the printer loses steps but whren I move the axis with pronterface, there is no offset.

Here is the gcode file for this print:

Dropbox gcode

If there are any ideas, how to solve this I would be happy

cheers

playdo

Check your belts and or drive gear on the motor, I was having the same problem and I kept adjusting the steps thinking it would work and it just got worse. I was sitting there and noticed the Y belt had so much slack it in I could see it lift before even moving the carriage. I tightened the belt a couple teeth and the set screws on the gear, problem gone, hope it helps.

your pulley is loose on the stepper shaft... If its loose and the stepper shaft has a flat you get that sort of behaviour as the pulley rotates but then catches on the edge of the flat shaft.

Edited 1 time(s). Last edit at 08/28/2017 07:50AM by Dust.

Thanks for these tips!

Seems that I have to tighten my belts quite much.

Is there some rule of thumb how much I have to tighten them?
Can they be too tight?