pic: 4464 Preseason Drive WIP

[Oblarg]

Originally Posted by JesseK

the wheels are much harder to remove

I wouldn't call it "much" harder. For the outer wheels, you remove a nut and pull the bolt. For the inner wheels, you loosen one shaft collar and pull the shaft. It's not as nice as just pulling the wheel off the end of the shaft, but it's hardly a problem.

and it is far easier to mis-align the axles which then causes chain/belt woes. Your manufacturing and wheel decisions may make these concerns less of an issue, however.

We manufactured this frame to very good tolerance, so misaligned axles really a problem at all. Wheel spacing is done with the stock VexPro delrin spacers (of which I am a huge fan), which remove any chance of having mis-aligned pulleys.

Gearbox removal is definitely an Achilles heal of WCD. Yet it can be mitigated by making a more bulletproof gearbox. We've experienced a bit of this both years we've done WCD, and this year will probably do steel output shafts as a result.

WCP's WCD blocks make chain access for chain maintenance irrelevant (assuming proper sprocket spacing). Even replacing an axle with limited access isn't an issue.

I will agree that WCD is a very good solution (449 used it last year, and in all likelihood will use it next year).

This design trades a bit of convenience in wheel access and a bit of space for much easier gearbox and belt access. We think it's a worthy trade-off.

An aside: The wheel wells are as big as they are so that this design can fit either 1.5'' VexPro traction wheels or Colsons. We'll decide which we like better as we test the thing. I do wish that VexPro sold a live-axle colson hub with a standard bolt circle for mounting pulleys, though, as it would save us one hex versahub and one hex bearing per side in that configuration. It's a minor gripe, though.

Originally Posted by Jared

I really agree with the maintenance comment. Being able to swap a gearbox in less than five minutes is a huge advantage.

I have to thank you again for the hex coupler idea - it's a wonderfully simple and elegant solution.