What kind of couplers do you have on the Zaxis ? If you don ' t already have flexible couplers , switch to flexible couplers . Make sure to leave the ends of the lead screws unrestricted , the linear rods should be the elements that restrict the motion of the Zaxis rather than the lead screws . Flexible couplers will help address issues caused by bent lead screws or misalignment between the lead screws and motor shaft . If that helps , but there is still some Zaxis wobble leftover , you can also try installing 17 damperastrosynmy 17 rmdamp dampers on the Zaxis stepper motors . This will actually allow the Zaxis stepper motors to rotate slightly relative to the frame of the 3 D printer , which will help to alleviate stress caused by the Xaxis carriage moving up and down Zaxis lead screws that aren ' t perfectly parallel . I ' m not sure how much of a difference this will make though .