6801 Ball Bearing

This is a nice bearing to use with the GM17 gear motor. You have to cut the knob off the casing, but then everything fits together nicely. I'm going to use it for a design that is laser cut from 5.2mm thick bamboo.

It's a bit more expensive, but it's a perfect fit for my application. It's 5mm wide and the bamboo is 5.2mm wide. It's a good fit in one layer of bamboo. It also have an inside diameter of 12mm. I often laser cut a piece to fit around the GM17 shaft. 12mm is wide enough to make a decent shaft because the GM17 shaft will take up most of an 8mm id bearing. It think they are around $30 for 10. The OpenSCAD model is in the English system. Maybe it will be useful to you.