pic: manually machinable swerve from 2471

[AlecMataloni]

Hey, this is really neat! I like how this feels very "compact", and doesn't look terribly difficult to machine. You certainly did a good job playing to your team's resources.

I do have one nitpick with this design though.

Right now, from what I can tell, it looks like you have the CIM pinion position determined by your screw locations, which for this application isn't ideal. Screws/rivets do a poor job of "locating" parts in an assembly, and ideally they shouldn't be used to do so. The screw's hole is over sized by design, and this clearance will introduce slop into your CIM shaft's position.

In FRC, this stuff usually doesn't matter a huge amount, except in the case of drive components which require precise distances. Depending on how big the CIM screw holes are sized on the module, your CIM's location and consequently your actual C-C belt distance could be off by more than you'd like.

I would mill a .75" hole for the shaft to go through, and use the .75" OD nub that's on the face of the CIM to properly locate the motor on the part. It'd be a waste to precisely mill all your holes, and still have inaccuracies in the system which could affect how your belt drive behaves.

EDIT: I realized that there's some slotted screw holes for tensioning that I missed; However, I'd still recommend making that hole .75", but extending it as a slot along with the screw holes.

That leads me to another question. How do you go about determining proper tension in your belts? I've struggled with this question for a while, as it seems difficult to do without using expensive instruments. Any tips?