[DampRobot]

Yeah, I'll echo what CalTrain is saying here. Seems like an interesting idea, but it looks like it has assembly/disassembly disadvantages. Although I don't like dead axle wheels, if I did, I'd probably just use the regular #10 screws that the wheels are designed for. If nothing else, they're easier to assembly, and you can replace them a lot more easily if they break. I've also never had a problem with a poorly radially aligned sprocket like you mentioned, so for me, it looks a bit like a solution in search of a problem.

On a separate note, those sprockets look poorly sized. With #25 chain, I would suspect that the smallest plate sprocket (32 teeth on AndyMark) would work just fine with 6" wheels. We ran roughtop 6" performance hex wheel with 16 tooth hex sprockets last year, and only ratcheted climbing the bridge. 60 tooth, or whatever you have here, looks like overkill.