Umikot 54mm with Compression Stop Bushings

The Umikot is great! However, I didn't like that the screws needed to be tightened most of the way then backed off ¼ turn, as that resulted in occasional binding and screws tightening/loosening during use until I added loctite to hold them in. Instead, I redesigned the upper mech and spin ring to have compression stops on each gear that act as bushings going through the spin ring itself. This way, you can tighten down the screws all the way and they stay tight, while allowing the spin ring to operate freely. The spin ring also has an outer ring added to help reduce the tippy-ness during spinning with the handle. Additionally, I modified the spin ring to have two ways to turn it, an external grip on the OD as well as the normal handle attachment, as a result it gets taller by about 6mm. CAD Onshape Workspace - Note: I modeled this very lazy, with lots of delete faces etc. Someone could spend more time and clean this up to be included in the original model tree. Printing For printing, designed both modified parts (upper mech and spin ring) to be printed upside down from the original orientation. Both now require supports: a thin raft on the spin ring and an outer ring to support the shoulder on the upper mech. However the supports are pretty minimal and don't interact with functional surfaces of the final part. The only new part added is the washer, which I'm printing because I don't have any M3 fender washers available. Any washer > 7 mm OD will work fine here. Print the lower housing and stand from the original Umikot model, there are no changes required to those models. Assembly For assembly, you need 5x M3x20 mm socket head cap screws 4x M3 washers Assemble like the normal Umikot, except tighten down the main fasteners to fully snug and don't back them off at all. They will tighten up against the face of the bushing protruding from the gears and rotate freely with the gears. I lightly lubricated my assembly with a few drops of food-safe mineral oil, but you can also run this dry. If you chose to lubricate, just place a few drops into the outer ring gear and spin for 20-30 turns until it's evenly distributed.