Shapeoko Pro X-Axis Issue - Need Help!


I have had my Pro XXL for about 6 weeks. Since the initial assembly, the x-axis movement has not been very smooth. Initializing the machine created noticeable vibration when moving along the axis (compared to the y-axis). Despite this, I was able to move forward and complete a few short cut jobs over the first few weeks.

After a while, the z-axis started “slipping” when moving along the x-axis rapidly and could not complete the initialization cycle (z-axis never reaches the x/y limit switches). I reassembled the axis, cleaned/lubricated the rails with Vactra No. 2, re-tensioned the belt, and reconfigured the machine in CM. This allowed the initialization to complete, but the vibration still remained.

After about a week of minimal use the “slipping” returned. I completed the above steps again, which and had similar results. This brings us to where I am now. Sometimes I can complete the initialization, sometimes not. When I do, the machine will eventually fail during a cut job with the x-axis stuck not moving at all, just constantly “slipping” in-place.

I have provided several videos that show the condition of my machine, and what exactly is going wrong during a simple concentric circle operation I created specifically for this purpose. Any help or advice whatsoever would be greatly appreciated! There is probably a simple fix, but I am out of ideas at this point.

TLDR: X-axis movement issue. See videos at link.

Please contact us at about this and we’ll do our best to get this sorted out with you.

Well the sound is quite characteristic, along with your close up video, the X pulley is slipping on the belt and thus the Z carriage is not moving in X.

As for why that’s happening, whether there’s excess rolling resistance on the X rails, insufficient tension on the X belt or some damage to the X motor toothed pulley, I’m sure support will get you through that.


Just looking at the X Axis and Motor video it looks as it the toothed gear is not tight on the motor shaft. The alignment of one of the locking set screws should be positioned so it seats squarely on the flat on the motor shaft.


As with all Shapeoko stepper motors you can put a permanent marker across the end of the pulley and the stepper motor shaft. This is called a witness mark and tells you after running if the pulley and motor shaft have slipped or not. I do not have a Pro but on the older Shapeoko 3 you can replace the pulley set screws with longer metric cap screws and that makes tightening them easier and less likely to strip t he tiny set screws. Just make sure a longer cap screw will not interfere 360 degrees around t he stepper motor.

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Thanks for the replies and for taking the time to review this info. After working with support, the problem was determined to be caused by excessive binding in the x-axis linear rails (the cause of which is unknown). I was shipped a new complete x-axis gantry via FedEx overnight, and have since completed the repairs. My machine is back running and has completed several 2 hour cuts without any issues! So far so good!