Why is my Z-axis slipping

And how do I fix it? This has been going on in one shape or the other since I have had it. closer to the material it doesn’t do it, but makes using the home button pretty worthless? I am pretty sure the best it tight, but I am open to suggestion. I will eventually upgrade to a linear access, but since I bought V-carve Desktop this month I need to hold off. Thoughts?

Video of Z-axis Trouble

Z-axis problems may be caused by one of the following:

EDIT: mixed up which window was on what site

Springs? You have Springs on your machine?


Also check the pot or current going to the motor and check that there is no loose wires.

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Good catch. My apologies. Mixed up which window was on which site. I’ve edited my post so as to hopefully be more helpful.

I will check those things. Once thing I realized that video doesn’t show is at the lower levels it works fine. I have been living with this for months though using the 3 triquerta block it will get into the slipping range some times.

You likely have a mechanical binding, possibly due to misalignment of the top bearing mount. Try loosening the mounting screws slightly to allow it to align itself as the Z axis reaches its highest position. Then re-tighten after homing concludes. On mine I had to add a shim between the Z axis nut and the router plate to eliminate the binding.


Use blue locktite on those nuts even though they are nylon locking types. I do and it prevents slipping.

The mounter screws for the motor or the router?

top bearing mount PLATE

Loosening the two screws on top allowed it to move without slipping. Thanks so much for telling me to look there. I would have never thought of that. It seems like I am going to have to shim mine too since it still binds when I tighten it back up in that the top position.

I may have more questions when I get a chance to try and finish it. Again, really thanks so much for the help.

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Mine was doing this exact same thing. I tracked the issue down to the 2 screws that attach the z-gantry to the delrin nut. The assembly instructions actually say these should be just over finger tight, but I had them too tight. I loosened them and used blue loctite and its perfectly smooth now.

Before I was compensating by loosening the v-wheels slightly, but I would end jobs with the Z-axis lower than it should have been (ie skipping z steps up, likely going to safe-z between toolpaths). Now my wheels are nice and snug.

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