I was wondering what materials your robots are going to be made out of. Steel, aluminum, lexan, composites, etc.
Some of all three, but you forgot some of the other major possibilities wishes and dreams. Wishes and dreams can hold a robot together just as well as nuts and bolts.
Our robot is about 90% aluminum. The gears are of course made of steel and there will probably be some Lexan for our electronics board.
Lots of different aluminum, angle, 80/20, plate, and even some kit metal.
the other stuff will be lexan for electronics and pnuematics, and whatever the wheels are made of.
1/4 inch steel tubing (with thin wall ) all the way man 
Mostly out of 28mm aluminum extrusion - deanodized and reanodized, of course! Also some 1" square aluminum tubing (1/8" wall) and a bit of lexan here and there.
aluminum, steel, lexan, kitbot, skyway wheel material, polyethylene, unistrut…that’s all so far…maybe wood too
we have a aluminum, lexan, steel, rubber and so on…
"I’m a lumberjack, and I’m okay.
I sleep all night. I work all day
I cut down trees. I skip and jump.
I like to press wild flowers.
I put on women’s clothing
And hang around in bars"
5 years running… .500" 9ply baltic birch. Thats whats up Elgin. 
our robot is mostly aluminum. our electronics board is made of wood.
aluminum(the kitbot chassis) and lexan mostly. The only steel you’ll find is where we have to use it. And systemetric didn’t you guys learn from last year, aluminum is your friend not steel 
steel rocks my socks off.
but we do have a bit of aluminum for the gearboxes and electronics board and such.
If you want to see a really cool material check this out.
Aluminum honeycomb composite
I stumbled across it one day in the McMaster Carr catalog. (a little light reading material 
)
Pg 3363
-0.6 lbs/foot^2 for 1/4" thickness
-compare to 3.6 lbs/foot^2 of 1/4" aluminum sheet
I’m not even going to speculate some of the possible uses for this on a FIRST robot. BEWARE the price 8$ -12$ a square foot depending on thickness
Baltic 1/2" plywood base
welded thin wall aluminum tube for appendages
Six wheel drive, four motors, three speeds: In other words, we insist that wood is a design decision, and not a lack of options.
Don’t tell anyone, but wood is easily machined, easily fastened, and, pound for pound, is stiffer than any material normally used in these robots. It is also elastic and cheap. The lower component of our arm is made up of high-quality zero-void plywood I-beams that we fabricated ourselves. Our bumpers and electronics platform are also wood. We are also using aluminum and steel.
Some of us wanted to use carbon fiber tubes but we couldn’t get the material quickly and some people on the team (ahem, not me, but some of the students) were leery of using something that they had no experience with. A friend of mine made a 26-foot-long 3-inch-diameter sailboat mast out of carbon fiber, biaxial fiberglass, and epoxy. It weighed six pounds. OK, so his partner helped design one of the carbon-fiber/epoxy America’s Cup yachts, but it was still pretty impressive. And he sells the kits for a non-vacuum-bag, no-oven-required building method.
- Rick
we typically use aluminum. For most of the structure we use aluminum box tubing. The base has 1/8inch wall box tubing, and the rest is mostly 1/16 wall. Certain plates we need are usually 1/4 aluminum plate.
95% aluminum, some steel chains and lexan for the electronics board.
it depends on the parts of course–but steel, aluminum, lexan we don’t use wood though
to bad not duct tape
happy building!! 
machining the parts is fun
Gulfstream Aerospace in Appleton uses this material for bulkheads in the private/corporate jets they customize. VERY pricey but they are willing to donate scraps to our team. We haven’t used it on our robots but it makes a great floor pan for a Super Mileage Vehicle. Unbelievably strong for it’s weight.
As for what we are using on this year’s robot…
- 80/20
- FRP (fiberglass reinforced plastic - see our robot from 2004)
- Polycarbonate
- Aluminum plate
- Aluminum tubing - 3.0" OD with .065" wall
- Steel Gears
- Glass impregnated plastic sprockets - VERY light and amazingly strong - only one small hairline crack on our 2004 robot.
That should just about cover it.
Sean
I think it’s funny that you people actually plan on what materials you use we have to resort to whatever we find in one of the 4 workshops we have to work in. All in all it’s amounted to:
5/8 case hardened Thomson shaft
1/8" aluminum plate
high-speed steel -I used a drill bit for a pin, isn’t that amazing?
.500"X.500" steel bar (hell yea!)
.500"X.500" alumium bar
2X4, 2X3, 1.5X2 and 1X1 1/8" wall extruded aluminum
1.5"X1.5" angle aluminum
1/8" steel plate
plywood
kitbot aluminum
1/4" hardened steel dowel
BRASS!!!
plastic in 3 different forms
roller blade wheels
steel tape from a measuring tape
in consideration:
composite honeycomb board (fiberglass, not aluminum)
teflon
nylon
baltic plywood
diamond plate
1X1 angle aluminum
Like I said, we work with what we can “borrow” from various companies (NHI) colleges (dartmouth) and the government (I’m not joking about that one) our bot, if it works, will be insane, and your tax dollars will have supported it!