Monday, July 19, 2010

The wheels on the Kalamazoo go round and round

The theme of this week was: wheels!

After much thought and research and procrastination, I finally decided that making my own casters out of bike wheels was not a good use of my time. Unfortunately, the market for very large pneumatic casters is pretty much non-existent. If you want anything larger than a 12" diameter, you're going to have to pay hundreds of dollars. So, 12" casters it was.

These arrived Wednesday and were quickly mounted. The 4x4->4x4->2x4 pile is starting to look a bit Lincoln Loggy, but it's solid and serves the purpose of offsetting the casters enough to allow for the larger 20" drive wheels to be mounted and still keep the platform level.

This weekend I focused on the drive wheels. Preliminary tests indicate that I can convert cheap freewheeling bike wheels into fixies with the careful application of red locktite and metal epoxy. I haven't quite mastered the art of getting the ball bearings in place when I reassemble the hubs, but I'm confident that will eventually follow. But with a supply of cheap 20" fixed gear wheels, the last major open design problem was solved, and I just needed to mount them.

The general design for these brackets hasn't really changed since I first worked things out last fall. It was just a matter of working out the specific geometry to get them at the desired height.

After the V brackets were made, they were laid out in situ on the mounting plates bolted to the frame. These were tack-welded and then properly welded in a non-wood-based environment.

Ta da! I was even able to tip the Kalamazoo upright from being flat on its back, which meant levering it over on one wheel. This has been a concern of mine for the assembly process, and the wheel seemed to handle it without any problems.

It works! It's alarming mobile, actually, if you're standing on it. I might need to think about some kind of e-brake system or remotely removable chocks of some kind.

Coming up soon: final mounting of the pump arm pillow blocks and hopefully a shop trip to get the keyways cut and the pitman arm drilled out. Which would mean a working drive system (if maybe not a working steering/brake system) by next week!


  1. Bicycle brakes on the drive wheels. If you have a differential, you can use them to steer.

  2. Yes, that's the entire idea. :)