Colson Wheels??

There are a couple other local teams that could probably help you out with this project. You could take a look at 1477’s drive from 2012 (and the one they used this year, also WCD but IFI rough-top) and 624’s from this year (6 wheel Colson WCD) if you can. They used Colsons (not sure the specific ones) and a frame design nearly identical to the one you’ve posted, but with chains instead of belts.

My team is actually shares sponsors with 624, so I might have to take a trip down to their shop again and see what they think.

If you’re insistent on one belt run per side, I think the simplest belt path is this. You can see the real thing here. I personally prefer this system, where there is no need for idlers.

Some tips and tricks for this system:

1.Make sure your pulleys are large enough. We had 15t pulleys and 9mm belt in 2011 and the belts ratcheted pretty badly. Since then we have used 24t pulleys and 15mm belt with no problems.

  1. I assume those windows are for internal belts. I’d recommend covering them with 1/16 lexan to prevent debris from getting inside. You can see how we did that if you look closely in the pictures above.

  2. Think long and hard about how you are going to weld this. We have moved away from welding in recent years because it is faster for us to gusset. If you are going to weld this, I’d suggest using the belly pan and some gussets as a jig for the welder to keep everything square during welding and to make sure everything is assembled properly. The belly pan can be welded directly to the frame and the gussets can be removed at the end.

  3. Also think long and hard about how you are going to do your bumper rail. You can weld them, and if you do, I again suggest you mount the pieces in place first using some 8-32s. Alternatively, you could use rivet nuts to mount all the pieces together like we did here.

  4. You need a way to retain your axles. We put a snap ring on the inside and we tap the ends of our axles and retain the wheels with a bolt and washer, like we did here.

Thanks for all the info, this is really what I was looking for. My team is going to have a CADing session soon so I will bring up all these ideas.

Decision factors (from most important to least) were:

  1. We measured the friction coefficients of the HiGrip wheels (on carpet) and were favorably impressed.

  2. The weight and cost of the HiGrips were in the direction we wanted to go with our swerve units.

  3. Ease of mounting was tertiary consideration. That said, I’ve always been a big fan of easy when it doesn’t sacrifice performance.

Mechanically, we never had a problem with driving the Colsons, but the same is true (so far) with the HiGrips. The HiGrips do wear faster.