How to mount colson wheels in a live axle setup

[artdutra04]

Originally Posted by SuperNerd256

I'm looking into using Colson wheels next year (4"x2" or 5"x2"), but I don't know how to attach them to a live axle. I've looked around, and have seen many pictures and explanations, but it's still kinda confusing to me.

Can anyone tell me how to do this? Pictures would be great, if there are any.

Thanks!

Colson wheels are incredibly easy to work with in a live axle setup if you have access to a lathe, arbor press, and broach.

If you're looking to work with either the 1.5" or 2" wide Colson wheels, these have a 1-3/16" (1.1875") bore in the center. To convert this into a live axle setup, take aluminum round stock and turn it down on the lathe to an OD (outer diameter) of 1.200" +0.005"/-0.002". This is already a tight interference fit into the Colson hub, but some teams (such as 228) knurl the OD of the aluminum plug to provide extra holding force.

Generally the plug only has to be about half the thickness of the wheel, so a 0.8" to 1.0" long plug is all you need (Additionally, broaching anything thicker than 1.0" is usually quite difficult). Then you just use the arbor press to press the hub into the wheel. This step should take quite a bit of force, and may require a cheater bar and/or someone standing on the other side of the arbor press if its 3 Ton or smaller.

As long as you have a proper interference fit, you should never shear the pressed in plug out of the Colson wheel on a FRC robot.

If you'd like to have a CAD model of this approach, search for teams who have used Colson wheels before on CD-Media or FRC Designs.