Heard a clunk, then weird rotational sounds. Saw spring on bottom of screw drive

I was working on drilling some holes when I heard a clunk, and saw a plastic piece with a spring above it on my z-axis. I took a quick video, shut the machine down, and started to disassemble the Z-Axis plate.

Behind it, I found the what is shown in the picture. The top piece is what screws to the plate, and seems to move the Z-axis up and down. THe bottom plastic piece has holes, but no mounting ability, and the spring just drops to the bottom of the screw drive. Any idea how to fix this? In the middle of my CHristmas rush and my machine is down hard right now.


You should send an email to their Support (support@carbide3d.com) too, if you haven’t already.


The bottom part is the floating but to reduce blacklash, but it separated enough that it’s not going to be doing that.

If you’re in a rush, you can leave it there and reattach the spindle to the nut with inserts. If you don’t have excessive vertical play, then I think you’re good to go.


It’s the floating part of the anti-backlash nut. It just threads onto the rod, BUT you want the other portion close enough that the spring in-between them has a bit of compression.

If it’s come off, either your Z came down too far (and unthreaded it off the bottom), or the threads on the nut have stripped. If they’ve stripped, you can get a new one by writing to Support.

If the top nut feels snug on the threads of the rod, then it’s fine to run the machine without the other portion.

More details on the anti-backlash nut and installation:


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