95 has made many wood chassis robots. We found the most robust way to attach the panels together was with bolts and 90deg angle aluminum. The angle brackets can be drilled on a drill press, clamped in place on the plywood, then just match-drilled through. Our recipe was 1/2" plywood with 1"x1"x1/8" angle brackets and 1/4-20 fasteners, CNSK heads on the outside for a nice smooth finish, and hex-heads with washers everywhere else. 3"-4" of space between each bolt, FWIW.
Edit: we also used the 7-layer baltic plywood, it is good stuff.
1726 frames are awesome and a great inspiration to anyone making wood frames.
If you don’t like cantilevering wheels, 1771 also makes fantastic rigid frames. I saw that thing in Atlanta and it was solid as a rock. Maybe a little heavy but with so much material the frame could take anything.
We only made one mostly wood robot, it worked well. We glued/stapled the main chassis structure, taking time to figure out how to make the thickness of the different parts so they’d be strong where needed, and light where we could get away with it, and also be able to attach the parts together–for example using thicker wood where staples needed to go into the edge.
Also baltic birch is strong, but it’s kind of heavy, you might find that there are places in the robot where it would be better to use a less dense, thicker piece of plywood.
1771’s construction method is really neat, with the interlocking tabs. Like an R/C airplane fuselage…
My father (nor 92) owned a company that did die-cutting of cardboard. Back then, it was all hand-cut, but some of those dies are amazing.
For those unfamiliar, you first cut a thin line through plywood, then fill the space with a strip of razor steel “rule”. Squish the finished die onto a piece of cardboard, and viola’, you get cutouts. Think jigsaw puzzle. They used to get something like $10 an inch, decades ago. A typical 22 x 34 die might have 1000 inches of rule…
Consider using thin plywood with a fiberglass/epoxy coating where strength and low weight are a consideration. Do the math correctly, and wood can be pocketed like metal for weight savings without strength loss.
So that’s how it works…I always pondered that while gazing at jigsaw puzzles. I was on the right track, but had never figured it all out, and never remembered to look it up when there wasn’t a puzzle in front of me.
418 has done lots of work with wooden chassis and wheels. I personally have some experience with lightweight wooden boat construction. PM me if I can help in any way. a couple of years back we made a wooden chassis out of red oak (7 lbs) that is still knocking about as out promotion robot (should still be on CD someplace) and has had zero structural failures after many crash tests.
As far as I know we (1771) are the only team to do laser cut plywood construction so far. I will be happy to share all that we have learned as well as alternative woods and joining methods. You can without a doubt build a solid, light f4ame from plywood that requires nothing more than wood glue for assembly. Send me a pmwith your contact info and I will b happy to get in touch with y’all after christmas to talk through the design and construction aspects. In the mean time look at our pictures on here on here and also my pictures on picasa. My username on there is seanc56.
Team 1346 has done some great work with wood robots over the years. Jason Brett (dtengineering on CD) should be able to provide lots of details. Search his posts and I’m sure something will turn up. Here’s a picture accompanied by a detailed explanation: