Theraband Coupling Solution - Parametric

This should work better than zip-ties for binding Theraband elastic tubes to polypropylene rope/cord. Calibrated for the "black" tubes, OpenSCAD source files included if you want to adjust the parameters for the "silver" or other-sized tubes (be sure to copy your parameters to all 3 .scad files before printing the complete set!)

wall thickness: 1.6mm
top/bottom thickness: 1.2mm
plate adhesion: brim

I just used a Bowline Hitch for the loop connections, also recommend wetting the tube with rubbing alcohol before inserting the sphere on its cord held in place by a knot at the bulb-end.