This is actually wrong because I asked FIRST and they said you could not use any type!!!

Right, they were talking about timing belt that you can't use any type...Anything else you can get anything any size as long as the product has "belt" in it. This happens to be, conveyor "belt."

Well, three years ago we used Mectrol timing belt with high friction material on them. That was overkill, we hopped (yes, jumped a little) when point turning and burned out the motors. Two years ago we used the wheels that come in the kit, with no modifications - not enough traction for this year, but not bad for that game. Last year we used Mectrol belts again, this time without the high friction stuff. They were too slick, so we melted a criss-cross pattern on them with a soldering iron and roughened them up with abrasives, but we still didn't get quite enough traction to pull two goals up the ramp very well. This year we're using Skyway wheel hubs with rubber knobs from SPI (don't know what they're called) placed all around them. We've seen teams use these in the past with success, so we'll just find out how they work for us.

It seems like a lot of people are going to be using treads?

I think we're using the wheel-chair wheels Kacz100 mentioned previously. Bad part is they have really, really bad traction.

Anybody got any ideas??:confused:

Wheels
 

Skyway 10"x3" wheels are great.
Just use a belt sander and take the curve out of tread.
The result is a soft flat rubber tire that reminds me of an Indy Racer. ~14:1 geared Chiaphua's can turn 360's but only twice before popping the 30Amp breakers. You can't push the robot sideways. Ground clearance is 1/2". Wheels are on 3/4" shafts with thrust bearings to handle side loads.

rubber bumper treads
 

We're a rookie team, #802 and have been experimenting with various wheel and tread materials. The best we've found so far are the Small Parts 1" rubber bumpers (with steel washer) attached to a plywood sandwich wheel. The only trouble is that they don't seem last too long under extreme pushing or pulling conditions (ie. as we're spinning our wheels against very large loads). The carpet stays intact but the bumpers slowly disintegrate into black powdery dust and eventually come off completely as they wear down.

Does anyone have any insight or solution to this specific issue?

Thanks in advance,
Jeff

Coordinator and chief engineer for "The Lost Bearings". Lincoln-Sudbury High School, Sudbury, Ma.

Use a different material.

Anyone using unmodified Skyway Wheelchair wheels and feel that they will have enough traction this way??

We have been debating whether or not to modify our wheels =\

We tried the skywheels without modification and they seemed very slippery on the carpet. Our drive train is geared prettty low so our speed is about 5 feet per second.

We then roughed them up with a rasp and essentially flattened them at the same time. This was much better but still not good enough for our goals. We are experimenting with various treads and wheels now. I'm still not sure where we will end up.

Jeff

I have seen 'many' teams take a soldering iron to the wheel chair wheels to actually burn in a tread pattern. If I was using them at the minimum I would make them flat then get a tread pattern on them. If you are using 4 wheel drive, greatly enhance the traction on only 2 otherwise your robot will 'hop' trying to scrub off the traction to turn. There are a few rubber mats from small parts that can be applied to the outside circumference of the wheelchair wheels (glue + screw) that worked great for us in 2000. Also if you are going to do that and you chassis allows consider putting 2 wheels side by side then traction mat across both to make a wider wheel. Just remember about putting high traction on all 4, you have to overcome that to turn

Good Luck

Woo Hoo
 

We drove around for the first time with our bigger 4" wide wheels today and i no longer have fellings of doubt about our 2 wheel drive not getting enough traction! And our goal grabing mechanism (The Sickle of Death) is working beautifly.

if you do not think tracks are a good way of going ask some of the teams that went to Quincy.


With four motors that drive the track. the traction we got with our belts were great.

we moved anyone at any time without blowing breaks and without getting our motors even hot. we went 4 rounds back to back and the motors stay just warm. never did we blow a breaker.


and never lost a match. 5-0

we have now retaught our plans of picking up balls.

We now look like we will put our eggs in the basket of power and grabbing.

Can't wait til KSC

Recommend you test your wheels thouroughly on a carpet surface if you are using a belt as traction. We used a timing belt and attached it using epoxy to some wheels we manufactured out of aluminum and our drive had so much torque the belt delaminated and came off. So now we have come up with a much more secure fastening to the wheels and switch belts

Bleh!
 

damm Marcos, dont give away all our secrets!

Hmm, i see all you guys saying "we have 16 sq in." or stuff like that. well, my team has something close to i believe 194 sq in. i won't tell how, why, or what, but i will tell you that we have insane traction. :D