A SC8UU compatible linear bearing with M4 threads. No nuts required. You need a small nozzle (I used 0.3mm nozzle and 0.2mm layer height) and low layer height to be able to print the M4 thread (M4: 0.7mm pitch, 0.6mm groove depth, see photo) and the inner fins. Should the thread wear out a nut can still be conveniently used.

The good bushing shape is adapted from the LM8UU shape by FlyingMashedPotatoes (http://www.thingiverse.com/thing:631285) which really has some spring functionality.

• Version 1 has a smooth running thread which might wear off easily.
• Version 2 has a quite tight thread which will not wear but needs some force during screwing in.
• Version 3 allows for tilting in one direction to compensate bent rods (see colorful picture).
• A 'short' version is also made
• A long sc8wuu version added
• A stiffer version (for example for x-axis) was added

Drop a message if you encounter any problems or have suggestions.

--> Why using plastic bushings instead of bearings? Less noise, tighter grip of the rods - thus less jitter and mainly elimination of rod wear.

Note: Ensure that friction is very low (see post-printing) otherwise backlash may be introduced.