Rigid XEnds w/ Adjustable Endstop

These X-Ends build on prusajr's and my previous work to add a few neat features.

I found with the original prusa X-ends that the screws that held the x rods would slip when you tightened the X belt and that would pull the PLA bushings off the Z rods. You get a similar problem with LM8uu X ends but instead of pulling them off the rods, they flex the Z rods and as a result can cause the Z axiz to bind when you raise it closer to where the Z rods are constrained by the frame.

The push fit X ends sort of address the issue, but you would need to cut the length of the X rods very precisely.

This design has one X end closed and one open (but closeable by the insertion of a screw or piece of 3mm filament).

The closed end has a nut trap in the end so that you can install a tensioning screw. That allows you to precisely set the separation of the X ends and have them held rigidly at that distance regardless of the tensioning of the X belt without the need to cut the rods precisely.