Volleyball shift knob 50mm diameter

I was curious how difficult it would be to replicate the geometry of a volleyball in the Trimble Sketchup web app, so I designed this shift knob as an experiment. Sketchup is pretty limited when it comes to curved surfaces, so there was a lot of trial-and-error until I came up with a scheme for chopping up a sphere while keeping everything manifold. Blender would have been the better tool for those of us using free software for our designs, but projects like this really help you learn the limitations of your tools.

I designed this for a 2003 Toyota MR2 Spyder, but it likely fits many different cars. The hole is just under 12mm and unthreaded, so you can use the metal post of your transmission shifter to thread itself into the softer PETG. My i3-MK3 over prints holes about 0.2mm smaller than the design, which is just tight enough to get a nice tight grip.

Print instructions

Printer Brand: Prusa
Printer: I3 MK3S
Rafts: No
Supports: No
Resolution: 0.05 mm
Infill: 15%
Filament: Prusament PETG various
Notes:

Print one core and 5 bases (in a different color for more authentic look), then glue them together. I used Loctite GO2. Some minimal finishing work may be needed on the underside of the core if no supports are used.