pic: GBX-123 chassis example

The biggest negative (performance wise) to plywood over G10 is that it is thicker. If ground clearance is important it can make a difference. Otherwise its much easier to manufacture and secure components into(pre drill and then self tapping screws). The extra weight is negligible because it is so low to the ground.

I have to address a pet peeve here: anecdotal evidence. Stating a random example doesn’t prove or disprove anything.

Has anyone actually performed a statistical test on how wooden robots perform vs how metal robots do? I don’t know or suspect an answer, it just would be interesting to know.

I’m not sure there is large enough sample of wooden robots to draw any conclusions. Does anybody have a list of wooden robots?

You would need a massive sample size of wooden robotcs IMO. I mean, done right (like the Bit Buckets), you can have a robot as competitive or more competitive than a metal one. It really comes down to strategy, because I haven’t seen any significant differences in capability between the two yet.

Anecdotal evidence does prove that something is possible.

Statistical evidence can only prove a correlation. It cannot prove causation. Therefore there could be statistical evidence that wood robots perform better than metal robots, but the evidence could not show that robots perform better because they are made out of wood. For all we know wood robots could perform better because they are made by better teams.

Stating an anecdotal example does prove something in this case - that it’s possible to build a wooden robot that looks professional, which is what another poster was questioning. It does not prove that wooden robots tend to be good robots or that a good wooden robot is even possible. He only said that there was a professional looking wooden robot in Tesla this year.

A plywood bellypan is easily rattle-canned black, and no one would ever know it’s wood.

The wood we use is a 5 ply baltic birch at 6mm thick. It’s density is .025 lb/in^3.

For a structural bellypan two things are happening load wise.

  1. Shear loads are being transferred corner to corner.
  2. frame torsionally loads are reacted.

Most reasonable materials easily satisfy #1 if attached properly. The second is harder, and is one of the advantages of the plywood (over the garolite) due to stiffness. The increase in stiffness mainly comes from the much greater thickness.

We like the wood because it’s so easy to work with, and meets the performance specs we need. The garolite works, but is much harder to get cut how we need and costs far more.

We use perforated aluminum sheet like this stuff. It’s surprisingly strong, and offers plenty of pre-made spots for zipties and other cable management hardware. It’s not particularly heavy, either. The one thing I hate about it is that the holes don’t line up with component holes, but some precision drilling can make up for that.

Anyway, cool gearboxes. I couldn’t tell what you meant by a dropped swerve until I saw the modules in a base.

I’ve found that aluminum bellypans tend to be heavier than wooden ones, especially when just perforated with a hole pattern vs. putting in a diamod cutout. In order for aluminum to compete, is have to be very thin (around 1/16").