Question about the Z Nut Lock

I’m well on my way! I finished printing the parts and my hardware/electronics kit from Ryan arrived a couple of days ago and I have today off - woohoo!

I’ve got the conduits cut, the rollers assembled, and middle section assembled. I have a question though. Is the z nut lock supposed to “grab” the coupler nut? I printed both, and the coupler fits into one, but even with the screws tightened all the way down, I can still push the coupler nut out. Is it just meant to hold the nut in place, but not necessarily push and pull the z axis in both directions? I can tell that with the DW660, the weight alone would move the z axis down, but something like a pen holder or drag knife might not be heavy enough.

Anyway, I’m a little surprised that this piece seems a little loose. Most of my parts printed on the tight side and needed a little sanding or reaming.

Thanks in advance!

Hi Karltinsly,

I’m at the same stage as you are!

I printed the 13mm Z nut lock, as I’m using metric hardware, so an 8mm Z Axis screw.
I found that the coupler nut slid down to the bottom, and the clamp gap opened slightly, about .5mm.
Therefore I do not see the problem you are having.

But this coupler nut should not move, as you would loose all Z tolerance if it did!

I checked across the flats on my coupler nut, and it measures about 13.1mm.


Thanks, Greg. I measured my coupler nut, and it’s 11mm, so the 11mm nut lock is the one for me. Like my other parts, it was too tight at first, but a few minutes with a swiss file and I was able to press the coupler in with a c-clamp. It is definitely locked in place now. Thanks again!

Today I got everything put together except the z axis and the drive belts. Corner blocks, rollers, center section, legs, and stepper motors are all mounted. Woohoo! Just need to drill the z axis tubes and I should be able to start looking at the electronics. My DW660 and Ramps LCD arrived today too!