**5/19/2015 Updated EricCouplerRev3-5x5mm.stl for 5mm motor & 5mm threaded rod, M5 nut dimensions estimated. This should work for i3 machines and any other fine 5mm rods. let me know if the nut needs to be modified.
11/4/2013 v4.2, 6mm: Beveled the unsupported edge for the 6mm nut, Beveled the m3 Nylock grub screw hole and narrowed it .2mm, for a tighter fit. Please let me know if you need any other mods.
9/1/2013 modded v4 ->4.1: 6mm version for better 6mm nut fit and widened grub for a nylock nut. removed opposing grub and widened body to 22mm
8/26/13 Added 6mm and 8mm versions Bridged with a second opposite grub on the 5mm motor shaft.
Coupler for Z Axis, Revision 3: Beefed up a little. Created in PTC Creo
8/26/13 Added 6mm and 8mm versions, Bridged with a second opposite grub on the 5mm motor shaft.
This is the 3rd rendition of my Coupler, a few adjustments were made to make it more robust.
1.) I moved the nuttrap for the 5mm shaft down and back to increase strength, since mine were vibrating loose over time.
2.) I adjusted the supports in the large nut trap. I may close the top layer and try to print this with direct bridging instead of the supports. it might print more cleanly, but I'll save that for next time.
3.) I widened the bottom opening to make shaft insertion easier. the upper is still the same diameter for threading the rod into.
- Print 2x of these couplers.
- Insert a nut into the top, nut trap and push it down to line up with an M3 screw. Tighten onto your 5mm stepper shaft.
- Cut out the supports for the large trap, Insert a nut into the large trap.
- Thread a nut and a washer onto your threaded Z rod, then screw your rod up through the large trapped nut and into the coupler until it stops.
- Tighten the nut on the rod up against the washer and the bottom of the Coupler.
Your coupler should now be centered on the stepper motor shaft.
Please let me know if you need any changes. 4MM, added nuts etc.
I created these in PTC Creo Elements. it's free, and easy to use. Both .STL and .PK2 files are included.