MRBL - Printable bearing ball

This parametric model is designed to be fully printable. The sphere is divided into two halves to eliminate overhangs, an outer ring to keep the hemispheres aligned and two interlocking wedges, that tie all parts together.

The design is part of a case study for a bearing assembly, that is fully functional without any additional hardware. Printable bearings will normally come as needle or (tapered) roller bearings to avoid the necessity of support structures on spherical objects. For some assemblies (e.g. Rzeppa joints) spherical rolling elements are required. Simply printing balls using support structure wastes material, necessitates additional clean-up and is just not elegant.

Customization

This model is meant to be an inspiration and a subcomponent for greater projects - or just a marble. The attached Fusion file will support diameters starting from 15 mm to around 25 mm out of the box; Smaller or bigger values are possible with slight modifications.

Assembly

The tolerances are on purpose relatively tight. Press one hemisphere into the ring and the other half rotated by 180 degrees, so that the inside steps are facing away from each other. Insert the two wedges, so that their hooks point towards the aforementioned step. Use either pliers or a hammer to fully seat the latches.

Print Instructions

All materials will do, but polymers that are harder, like PLA or ASA may be preferable.

This model is optimized to be printed with a 0.4 mm nozzle at a layer height of ≤ 0.2 mm using the Arachne slicing Engine.