Eric's Improved Z Axis Coupler

thingiverse

UPDATE 1/12/2012 Added .PK2 and .STL for 4mm stepper shafts *EDIT Rev2, I made some adjustments to the columns and verified that the .PK2 file works in Creo again. I printed a new one and it looks better than the first one I uploaded. Let me know what you think. Use EricCoupler2 for the newer version.. I also found Thing# 12190, which is really similar, he made his first so I've listed this as a derivative though I created mine separately before I saw his. This coupler came from my seeing and experiencing issues with other couplers. I wanted a Z coupler that was round and would not snag any loose wires. I wanted one that I would not have to worry about slippage, and that would be beefy. After a little experimentation, I decided the captive nut idea was the best. This is my first posted Thing, so Comments are certainly welcome. I design objects with PTC Creo. It's awesome. Elements is Free. Instructions Print, Cut out the support columns, insert a 5/16 or 8MM nut in the big slot. Insert a 3mm nut in the little slot Then a short 3mm screw in the little hole to hold the 5mm motor shaft. Put a 5/16 or 8mm nut on your Z axis threaded rod, then screw the rod into the captive nut through the bottom hole till it stops, then tighten the nut below night too tight against the bottom. This provides a little wiggle, but should be centric to the motor shaft. See picture. Dimensions 20mmdia.x30mmtall