five sheets of 7/16" x 4’ x 8’ plywood, ten 8’ 2x4s, one 8’ 4x4, and a box of 1.5" deck screws. And some big screw eyes and rope to tie the robot down.
That’s off the top of my head…from last year’s crate. Looks like we’ll be able to use it again!
Have you read Section 4 yet? It has the general requirements. If you know the size, you can run the numbers.
Squirrel has it about right, though. The 2x4’s are for interior support, so you can’t have too many. Leftover scraps can be used to help tie down the robot
When you are building your crate remember that other crates chould be stacked ontop of yours for storage during the regional. No need to freak out about it as most solid crates wont have a problem with this, but some are not so solid.
Also remember that you want it to weigh LESS than 400 lbs, with the robot (and whatever other stuff) inside. You can use slightly thinner plywood, 3/8" is the minimum I would use. And you can possibly use 2x2" pieces of lumber instead of 2x4s, but they would more likely to split.
If you study the picture I posted above, you’ll see that it is designed to be built as several subassemblies (and can be disassembled into those subassemblies easily). The sides each have four 2x4s screwed to them, the top and bottom have two 2x4s on them, and the rear and (removed) front panel are just plywood. There is a lip along the bottom where the plywood extends past the rest of the crate, so that the front panel can rest on it to make it easier to hold while screwing it into place. The bottom has additional 2x4s to support the frame of the robot, the wheels sit in the recesses between the 2x4s so that they are not touching the crate…that way, they won’t be damaged by rough handling or rough roads.
I think you might also need some 3" long screws to attach the sides to the bottom, and for other miscellaneous uses.
Yes really be careful when it comes to weight, out crate has been over for a few years now and every year we pay extra because of it. Plus we have to lift it into the back of a semi and a few pounds makes all of the difference when you are lifting it above your head.
The other thing to be careful of is being able to open and close the crate multiple times without compromising the integrity. While we were at Purdue last year we were frantically drilling new holes because the screws had pulled out of the wood.
I have enclosed an estimative for the Crate #1 mentioned by Squirrel, it comes about at $87.50
Team 135 brings a good point about “…being able to open and close the crate multiple times without compromising the integrity…”
Does anyone have a list of material to make a “door” for a crate ?
If someone post the material necessary, I will go get an estimate for a Crate in which I will creatively call Crate #2.
Using screws to hold the opening sides of the crate on provides more structural integrity than using hinges and a hasp. The “stacking” strength of the crate I showed is based on the sides all being screwed in place, not hinged.
It is a matter of design, not material. I do not see a need for a hinged door, so I have not designed a crate with one. Maybe someone with a crated designed for an opening door will speak up?