Solved Z axis issue

Hello everybody I am new to 3d printing. I have had my Robo R1 plus for about five months now and the z axis is getting off kilter. When I start a print it does awesome for about the first 3 mm then the left side start going higher than the right side. When I notice this and cancel the print its about 2 to 3 mm higher on the left side then the right. If anyone can help that would be awesome. Thanks

 

Thanks guys I will look at the connector and the other stuff listed above tomorrow. Thanks again guys I will let you know what I figure out.

 

Well I checked the connectors on the both z axis motors and on the board side of the wires. They were all connected, I turn both leadscrews and they seemed to have the same amount of resistins. So how do I go about checking the stepper driver and the ramps board? Thanks

 

Hey guys I think I got it figured out. The stepper driver for the left z motor was at .461mv and the one for the right motor was at .765 mv. I turned the right one down to .465 mv and it seems to be printing good now. I think the one being at .765 was too high and getting it hot so it wouldn't move as well as the other one. Thanks guys for all the help!