pic: 1503's Off-Season Project

[Pat Fairbank]

Originally Posted by Brandon Holley

Just a quick question about the banebots wheels, because we were very strongly considering using them (we ordered several in different durometers, etc.)... Did you do any kind of testing with them? Such as, seeing if the hex within the polypropylene hub would strip out? Or if the urethane shears off when being pushed sideways?

Now that you mention it, I remember some issues with the Banebots wheels that I should share. We ordered some keyed and hexed wheels to test with, and weren't very happy with the quality of the wheel manufacturing. Some of the hexes were visibly off-centre, and produced as much as 1/8" of runout when mounted on hex shaft. We also found that some of the molded surfaces weren't always perpendicular or flat. So we gave up on the idea of being able to drive the wheels directly by hex or keyway, and instead made a fixture consisting of a 3-7/8" circle milled into a block of aluminium. We clamped each wheel into the fixture and ran a CNC program to mill out the wheel centres to 7/8" and drill a bolt hole circle matching the sprockets, using the OD to locate. So, our centre wheels are driven by the shaft via the keyed hub they are bolted to, and our front and back wheels are driven by the sprockets they are bolted to (and are mounted on dead axles).

As far as the tread material goes, I'm not concerned about it shearing off. We cut a wheel in half, and the outside of the molded plastic wheel has a section in the middle which sticks up into the tread (i.e. the tread/wheel interface is not flat). The adhesive also seems to be ridiculously strong.