Allthread in the bundle

The allthread included in the bundle had the coupler nut, 3 regular nuts, and a spring. I know what the coupler is for, but how are the others used, and what is the spring for?



The spring is used to reduce backlash. There is an image (cutaway from a model) showing how to install it on the bottom of the home page. Look for z-nut lock.

Thanks, Curt. The picture makes it clear how to install, though I don’t know if I could install mine - I had to file and use a c-clamp to press the coupler nut into the z-nut lock. Maybe I could calibrate my printer a bit better and reprint if necessary. How does the spring and second nut reduce backlash?

Thanks again!


In theory, the space between the rod thread and the nut thread causes backlash.

If you hold the rod and nut in your hands you can pull the rod in and out of the nut, ever so slightly, this is backlash!

The spring would hold the thread faces (Rod and Nut) together, to close this small gap, and therefore remove the backlash.


Did you print with ABS or PLA? I struggled with how tight things were with PLA and ABS shrinks more. My coupler and nut were not tight with PLA and I ended up using some CA to hold it in place.

Greg, thanks for the explanation.

Curt, I printed in PLA. I had to file a little bit to get the coupler nut in. I’m okay with the z axis right now. I’m going to work on getting it running and cutting and in the meantime I’ll run some calibration prints and see if I can get it a little less tight. The only reason to redo the z nut lock is to be able to get the backlash spring in.

I’m not sure the backlash spring even does anything major I would say you are fine without it. I just used it in case there was an issue.