Z Nut Lock trouble

My Z Nut lock has broken again. This is the third one. The first two were printed from ABS and the screw holes split apart. The last one I printed from PLA and cracked vertically the entire length. I figured the ABS parts were just printed bad since the cracks were horizontal. This has to be the worst part to have to replace. Not much clearance to work with.

Is there a alternative part I could print?

Are you using the right one? There is an 11mm and a 13mm. If you bought the kit the 11mm is the correct one. You really should not need to go that tight. Clean the coupler nut to make sure there is not any grease on the outside surface and give it a snug that’s it.

Just in case. You are not supposed to be closing the gap on the smaller nut, you are only clamping the coupler. The bottom one should has to be loose.

I am using the 13. my coupling nuts measure 12.58mm I have printed a new Z Nut Lock this time in ABS and reinstalled. Everything is snug.I’ll keep an eye on this.
I took this time to add the universal mount system. Hopefully it works as well as it looks.
Once again thanks for your help.

Check your infill settings against the parts sheet

Jeremy can you please share the stl ?

They should both be on thingiverse.