12mm Hex Hub with Set Screw

thingiverse

This is a simple 12mm Hex hub that can fit on a foam wheel. There is a slot for a 4-40 captive nut. I usually super glue the foam wheels to the hub. If the 3mm D shaft is hard to fit onto your shaft you can gently heat the print to soften it for a better fit. Prints quickly and without supports Final printed weight with the set screw is under 5g. There are two variants for 10mm and 20mm wide wheels. Aluminum nuts (because they are light, but steel works too): https://www.mcmaster.com/93181A003/ 1/8" 4-40 Set Screws: https://www.mcmaster.com/91375A103/