Quote:
Originally Posted by CENTURION
Huh, very interesting, thanks for the correction!
This is a really great drive idea, much simpler than the others. I'm not super familiar with the Versaframe setup though, so I'm having trouble understanding the shifting front wheel.
Is it physically connected to that tensioning cam, welded or something? If not, how is it constrained, why doesn't it just slide around all over the place?
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There were a few things holding the VersaBlock in place on our original design. The tension of the chain held the block in the horizontal axis by pulling it tight against the cam (which was not physically connected, just rotated to achieve the correct chain tensioning). The "elastic tension" you see in the pdf consisted of surgical tubing pulling the block upward until the bottom lip of the block was tight against the bottom of the frame. The piston would overcome the force of the surgical tubing, sliding the wheel into the downward position.
As you've probably realized, this original design was a bit of a makeshift solution, and one of the modifications we made going into the off-season was to attach plates to the blocks that pivoted close to the omni wheel. That meant that the traction wheels, when actuated, would follow an arc rather than sliding up and down, keeping the chain tension more uniform throughout the range of motion. We saw a much more smooth and consistent actuation. I attached an image of a quick mock up to show you basically what it looks like now.
In future iterations we could possibly move the plate's pivoting point back to the omni wheel's shaft, so that the traction wheel would follow an arc such that the chain would always be the same tension.
https://www.dropbox.com/s/1ffm7908vk...nActuation.bmp