pic: GUS Team 228's Prototype Sheet Metal 6WD Chassis

[Rob Stehlik]

Brandon,
Thanks for the info on Colson wheels. I got a sample from Mcmaster a while ago, and they do seem to be nice wheels. Obviously they were never intended to be powered, which is why they are difficult to mount hubs to. The one I got has a 1/2" bore, but this is with plastic bushings. The hub itself is 7/8", which could be broached, but now that you mention it, the plastic is a bit soft, and may not hold up well under stress. I was looking for an alternative to knurling because while we do have the tools, it seems like it would be a bit time consuming to get it right on a manual lathe.
I guess with Colsons the initial effort to mount them is offset by the benefit of never having to change treads.
Rob

Originally Posted by Brandon Holley

Rob- I'll let Art handle the rest of your questions, but I think I can handle this one, as I'm a huge fan of Colson wheels as well.



Colson wheels typically have large inner diameters as you can see in this above image. The hub is a thermoplastic of some sort. My experience with Colson wheels has been nothing short of spectacular....AFTER you get them mounted to a robot. As far as wheels go, they can be a bit tricky to design with. I like Art's knurled insert design because it simplifies the hub design greatly.

In the past I've made hubs that fit into the inner diameter and then have grooves cutout that grab the ribs around the hub of the wheel. They worked well, but are a relatively complex part for just being a wheel hub.

So to answer your question, hex broaching these wheels would be quite difficult knowing that the diameter of the inner hole on the wheel is already quite large. Also, the plastic hub makes for a less than ideal hex broach solution because of the material properties of plastics (shaft will strip out inside hub).

-Brando