The original gear bearing on Thingiverse was posted with an OpenSCAD model that had the parameterized diameter of 55 mm. From the caster wheel experiments a few design issues popped up. Is there a better configuration of planet quantity and size? Is there a better way to attach the center than the 1/4″ hex hole in the center of the sun gear? Can features be added to prevent warpage of the outer ring during printing?
Here’s a pictorial of some of the tweaked designs and configurations to answer those questions. Some of the gear bearings use a 60 mm outer diameter. Some have larger sun gears. On has a ring and large external hex protrusion for solid attachment. We find the grooves around the outer diameter provide some aesthetics as well as strength and also as a sort of cooling fin to minimize warpage. OpenSCAD was used to develop these variations.