pic: Mecanum Musings

Originally Posted by squirrel

What would happen if you tried to use a smaller hex for the central hub?

Not sure. Next time I boot my Mac into windows to do some CAD, I'll throw together a different version with smaller hex. But to be honest, I'm not sure I'd feel comfortable making it any smaller. The team I'm mentoring has an affinity for Banebots transmissions, so I think the goal is to keep to wheels that can be direct driven off a BB tranny.

Originally Posted by JesseK

For even less necessary machining, you could not mill out the inside of the hex stock, and instead thread-tap the holes where the counter-sunk screws go in. This makes it a bit heavier, but you wouldn't need a mill to make the wheel.

Then, you could also drill the KOP hub bolt-circle pattern into the side, eliminating the necessity of having to make a key way.

To take this even further, instead of counter-sunk screws you could use half-head-height machine bolts, eliminating the need to create the extra dimple after the initial hole is drilled.

There are definitely many revisions that could be made to seriously reduce machining time, but this is really just a 1.0 wheel. I'm debating changing the milling operation on the hex to be entirely one sided, so the "dishing" of the wheel would be done in a single Mill op. I'll have to do some FEA tests to see how the strength would stack up.

Also, for the rough ride concerns: Once I make the wheel wider, and thus the rollers longer, the wheel actually smooths out a good bit.