Customizable Shaft Buddy: A shaft coupler/adapter generator

Overview: This customizer can generate a shaft coupler that accepts a shaft (female) or acts as one (male) on either end for a variety of shaft shapes (hex, square, round (with set screws), and round with one or two flats).

"Sleeve" mode: In addition to generating the usual two-sided couplers, it has a special mode to adapt a smaller shaft of one form to a significantly larger one -- it can create a single-form "sleeve" that goes around the smaller shaft, boosting it up to the larger shaft size. To use this mode, set shaft 1 to male, shaft 2 to female, and make sure that shaft 1 is significantly larger than shaft 2. You can disable this special behavior by setting disable_single_form to "yes".

Background: A while back, I wrote a simple set-screw coupler generator for round shafts. Then I needed to convert a 5/16" round shaft with a 2mm keyway to a 1/2" hex shaft, so I wrote a one-off SCAD script to do that. Then I needed yet another coupler, so I wrote that one too. Then I decided I never wanted to design another coupler again, so I wrote this to hopefully solve the problem forever.

Update Jan 2018: Added an option to force set screws for non-round shafts (e.g. hex, square, etc.).

HOW TO CUSTOMIZE: This model was originally made for Thingiverse's customizer, but you can customize it yourself. Just load the scad file in OpenSCAD and edit the commented parameters. F5 to preview, F6 to finalize, then save to STL.

Print instructions

Set infill according to the strength needed.

Important: Depending on your settings, you may need to flip your coupler upside down to avoid unnecessary overhangs. If you do this, you shouldn't ever need supports.