[z_beeblebrox]

Originally Posted by asid61

Can you swtich to COTS shifting gearboxes? A good portion of the advantage of a six cim drive is lost when using single speed, because going at any speed where the acceleration difference (between 4 and six cims) is not negligible is just asking for breaker blows.

On another note, that's a really good weight and design. The way you are fitting wodden plates together is very novel.
How do you make the correct tolerances on everything?

By changing the hole pattern on the inside chassis plate and possibly the size of the clearance holes in the belly pan and top plate, we can switch to 3 CIM ball shifters. For this version, we're using single speed gearboxes because we already had most of the parts on hand and wanted to test making wood gearbox plates.

Tolerances are largely determined by trial and error. Since laser-cut wood is so fast and cheap to make, we can make multiple iterations of a part in a day. We're cutting the slots and tabs to nominal dimensions; the laser kerf makes them a tight, but still easy-to-assemble fit. For bearing hole sizes, we're cutting a test part today with holes of slightly different sizes to see which works the best.