Very nice design! I’m glad to see everyone is keeping up with robotics individually as we’re forced to stop meeting as a team. With the combination of the number of swerve drive models we have now, I bet that we’ll be able to start prototyping one for real once we get back together.
I took a look at the CAD for a few minutes and have a few notes:
- The lever shifter is a really cool solution to packaging the shifter piston. That being said, I’d doubt whether the challenges that come with a shifting swerve are worth it for the limited advantages in real life.
- The lever bar is unnecessarily difficult to machine. It’s not flat on any face so we would have a very hard time making it on the router.
- Not sure how you’re getting a 19.26:1 rotation ratio. I see a 6:30 gear reduction and 18:59 belt reduction, which is a total of 16.39:1. You can bump that up pretty easily though by reducing the smaller pulley to 14t (would need to be custom machined, but we would probably do that anyway) and increasing the larger gear to 40t. That would give you 28.1:1, which gets you to a much lower current while still being plenty fast.
- The top pockets on the main turning pulley are dangerously close to the root of the pulley teeth (< 0.5mm clearance at some points). They should probably get pushed further in.
- Right now the main turning pulley needs to be flipped to machine the top pockets and bearing flange recesses. If you can move all of the pockets to the bottom and put the flanges outside the bottom face, the entire thing can be machined in one setup (upside-down) which will greatly reduce machining time and improve accuracy.
- The wheel bearings and spacers don’t seem to be the right size for the bolt they’re sitting on
- If you’re using a shoulder bolt as a wheel axle, you want the shoulder to go all the way into the opposite side wheel leg. See this cross-section from the SDS MK2:
Overall though, looks very good!