Tony, Rob and I pushed the Kalamazoo up to the road from the garage today to do some real testing. As the video shows, the results were pretty bad.
Time for me to eat an entire murder of crows: differential braking for steering does not work here. At all. I now have a bit over two weeks in which to design and build something completely different.
The action is really jerky, with a massive clank at the top and bottom of the stroke. Haven't quite figured this out yet, might be related to slack in the chain drive. I know how to minimize the noise, at least, but I really want it running smoother than this.
Less seriously, but still annoyingly, we broke the fixed gear connection on one of the drive wheels. Hopefully I can just pay to get some real ones made up at Recycled Cycles. A cash-soluble problem, as I like to say. If that fails, I can always flip that one wheel around. It would break the symmetry of the drive chains (grrrr), but then it would be turning in the correct direction at least when driving forward. I cut the keyway extra long on that shaft precisely to handle this contingency.
I won't deny it, I'm now worried about getting this working in time. Particularly with the Laser Medusa Helmet work I also want to get done. Overall I'm really proud of the work so far, just have to get these last problems sorted out. We'll see...