Plywood - talk to us about how you use plywood

[JamesCH95]

Team 95 has used plywood chassis numerous times in the past. Some pictures:

http://www.frcteam95.org/wp/picasa2/...aszetaArchives

http://www.frcteam95.org/wp/picasa2/?album=Archives

Very simple implementation: plywood sheets cut to size usually with a combination of table, circular, and jig saws, and then bolted together with 1x1x0.125 angle aluminum and 1/4-20 bolts. Countersunk bolt heads on outside surfaces of the robot.

Probably not the lightest assembly method ever, but every robot built this way survived quite nicely in the days before bumpers. It is also very cheap and easy to assemble and build with only basic hand tools (circular saw, jig saw, and a drill will get you there) and doesn't require a ton of precision to work well.

9-layer baltic birch is what we've used in basically every instance. Easily available at Home Depot and other hardware stores, very strong, and comes with a good finish.

[GBK]

We have used plywood for something for the last 4 years. In Logomotion we used 3/4 in plywood for fins to line up to the tower to deploy the mini bot. Worked great until we got to MSC and broke 5 of them, all on the same side. I almost felt bad for the student that spent almost an entire day at MSC making replacements. We of course did not bring enough plywood to make all the replacements, but were able to scrounge enough. I remember team 141 was ready to tear apart the pier awards they made to hand out so we could have wood to make replacements. (thankfully we did not have to go to that extreme) The student ended up making one out of 1/2 in plywood framed with aluminum angle. Somehow we never broke that one. Bent the heck out of the bracket that mounted it to the frame though.

[bbradf44]

We usually use wood for our electrical board in case something gets overlooked, crossed, done wrong by a freshy it won't effect the metal components of the robot. And its cheap

[fb39ca4]

Originally Posted by Ian Curtis

We have not used that much of it in the past, but our pit neighbors in Seattle did. 1899 had a gorgeous plywood robot, and we plan on borrowing some of their construction techniques this season.

I've attached a few pictures I took at Seattle this year. For robot building they had cycled through a bunch of different kinds, but ultimately settled on this 5mm sanded ply, which is actually slightly thinner than 5mm. It is super cheap (under $15 for a 4x8 sheet). They sealed it as sheets, and then just put it in the laser cutter and got out puzzle pieces. In cutting the joints they didn't consider the kerf of the laser and the joints were definitely plenty tight.

Because the wood is so cheap, they built multiple iterations of their frame. I forget the exact number but it was at least five. Due to the puzzle-piece nature they also had some fun figuring out the best order to put it together. To hold it together they buy wood glue in 5 gallon buckets, and spent a sizable amount of money on Harbor Freight clamps. Anyone who went to their pit can attest that they had a lot of clamps.

If someone from 1899 is around feel free to correct me or send me a PM, because I've actually got a few more questions.

1899 member here. You got most of that correct, except the plywood we used was slightly over 5mm-5.2 to be exact. We originally used wood that was 5.1mm thick, but it had issues with voids and the filler used in them not being cut all the way through, while the final wood we ended up using did not have that problem. However, our CAD model still had slots for 5.1mm wood in many areas, and we never got around to changing them after switching to the 5.2mm wood, which is why the joints were tight. Also, I believe we built eight chassis, including the competition one, and a backup chassis we bagged with the robot in case the main one was irreparably damaged.

[s_forbes]

One of the best robots I got to help design was made of plywood. Our chassis design used various thicknesses of baltic birch plywood (1/2, 3/4) depending on the load seen by each frame member. Some lower quality 1/4" plywood was used to brace the frame members. All were held together with good wood glue and long staples. We were fortunate enough to have a shop with good saws to get all the pieces cut precisely, and a pneumatic staple gun. 2009 was a year with low loads on the drivetrain, so this was a great material.

http://www.chiefdelphi.com/media/photos/32671

To my knowledge this is the only robot built with 2x4s and plumbing supplies to win a quality award. Krylon paint works wonders!

[fb39ca4]

Originally Posted by s_forbes

To my knowledge this is the only robot built with 2x4s and plumbing supplies to win a quality award. Krylon paint works wonders!

Speaking of plumbing supplies, there was a team at Championships this year that had a PVC pipe chassis. Anyone remember which team that was?

[Jaxom]

Originally Posted by fb39ca4

Speaking of plumbing supplies, there was a team at Championships this year that had a PVC pipe chassis. Anyone remember which team that was?

1810 from Mill Valley HS in Shawnee KS was in Curie. They've been using PVC as a primary building material for years. Pretty much a fixture here in the Kansas City region.