Spacer for Delrin V-wheels

My Mini Kossel uses machined Delrin wheels that run in the slots of 1515 extrusion. These wheels each hold two 623zz bearings, but it is impossible to grip them tightly on the shaft because they are supported only on one side. Tightening the nuts applies shear to the bearings, which can ruin them. This spacer goes between the pair of bearings and holds them apart so that you can tighten up the nuts on either side; the inner races then bind firmly between the nuts and spacers, while the outer races still roll smoothly.

Print instructions

Category: 3D Printer Parts Print Settings

Printer: Mini Kossel

Rafts: Doesn't Matter

Supports: No

Resolution: 0.2 mm layers

Infill: N/A

Notes:

They come out at about 3.6 mm (using 0.2 mm layers) tall, which is slightly longer than the space needed, but tightening the nuts on either side compresses them just about enough. If your printer makes a mess of the ends, you can print slightly longer ones and sand the ends.

The hole is intended to fit an M3 bolt without engaging the threads; depending on your slicer and filament you may need to adjust the model inner diameter (I had to bump it up to 3.6 mm to get holes of actual size 3 mm).

If you only have one printer and you're printing these to upgrade it, you will probably want to print some extras in case some are too short or slightly malformed.