Replicator 2X pulley slip

[Feliks87]

hello fellow Makers

as the title indicates I have a problem with my x-axis stepper/pulley/belt

I received my new Rep2X yesterday and did some test runs right out of the box with overall satisfying results except one problem:
the x-axis is slightly offset randomly in every print
this results in circles not being round which is the biggest part of the problem



I did a print of the "Multiple Calibration Print" which confirms my x-axis problem with an offset of ~0.6mm
strange enough this offset not always happens so I did the following steps according to makerbot support page

• tighten the x-axis belt
• tighten the x-axis pulley screw
• switch x and y Botstep on the Mightyboard

none of this solved the problem and while checking the Rep2X parts I noticed that there is a slight slip of the pulley when I pull on the belt and the stepper motor is not affected by this
as mentioned I already tightened the pulley screw as much as possible without ruining the screw head but it didn't help



I did the same belt pulling on the y-axis stepper motor but it didn't move a bit

now my question is if there is anything else I could try exept getting a new pulley/stepper motor which might be my last option
thanks in advance for your help