And the Wheel Goes 'Round and 'Round
 

This year we used the KOP wheels, but Next Year I would like to see our team upgrade. Today's big question: what are the best wheels if you want to build a Big Dog Chassis that really grips and goes?

Re: And the Wheel Goes 'Round and 'Round
 

It seems like those Omni-Wheels are really good for moving. They're expensive, though, so a lot of teams were talking about how they made them with their own plastic molds for a lot cheaper. I would reccommend those wheels out of all of them, probably made with a poly-urathane (sp?) type plastic. Just from roller-blading experience, that type of plastic sticks really well to most floors. Hope that helps...

Re: And the Wheel Goes 'Round and 'Round
 

for purchased wheels with lots of traction, I like the skyway pneumatic knobbies. I believe they're 6.75" in diameter and they have a tread that's about 2" wide. They give tons of grip, but watchout for not being able to turn due to gearing.

You can make your own fairly easily by taking the KOP wheels, mounting them up on a lathe, and turning the thread down until it's flat. You can then glue/bolt/otherwise attach your favorite traction material to it.

Re: And the Wheel Goes 'Round and 'Round
 

If you don't want to do any work yourselves and if you don't want the bouncing often associated with pneumatic tires, you can buy tread-less wheels with neoprene or gum rubber. Both substances really grip well, but you have to make sure to keep their surfaces relatively free of dust and grime.

Re: And the Wheel Goes 'Round and 'Round
 

/me points at last years bot

it has 3i nch thick weheels made from standard red/white plywood, 25mmx3. Then covered in a really grippy rubber. Soo grippy we couldn't turn, but went really really really fast in a straight line... it still didn't turn when we took the rubber down a lot and sloped it so it could stay on the middle platform....

Re: And the Wheel Goes 'Round and 'Round
 

If you want to keep your turning you might think about using gum rubber rollers on omni wheels.

Re: And the Wheel Goes 'Round and 'Round
 

I'm not sure what kind of "upgrade" you are looking for but a lot of teams use McMaster Wedge-Top Incline Conveyor Belting for tread. Is is about the most grippy stuff you can get; you don't have to use a very wide wheel. Many teams put the skyway wheels in a lathe and turn them down just until the tread is flat, and then screw this stuff on. The one problem is that this stuff is so grippy that your robot will not turn unless you have 6 wheels with the center wheel lower or a different kind of wheel on the opposite two.

In 2003 we used the Skyway beadlock wheels with the standard foam-rubber tread that comes on them, turned down until they were flat/smooth. They look really slick, but grip really well. As long as your track width is more than your wheelbase, these turn okay.

Re: And the Wheel Goes 'Round and 'Round
 

This year we are using 6 in Colson wheels with aluminum hubs. They are built tough for "Battlebots" :( but they sure work well for our application. I can barely push our bot sideways. The only problem they are very expensive at $50 a piece and we are using six of them. We ordered them from CNCbotparts.com.

Re: And the Wheel Goes 'Round and 'Round
 

I'm not sure what sort of machining capability you have but the wheels without hubs are available for much less here http://robotcombat.com/marketplace_colsons.html

EDIT: And here are some very similar wheels with hubs for cheap, but the hubs are Delrin.

We have used the 6" ones direct on this motor before in a special project without problems, but it was not a competition robot (did not engage in pushing matches). Also, it should be noted that there were two wheels per motor, one on each side.

Re: And the Wheel Goes 'Round and 'Round
 

Thanks for all the suggestions, folks. I'm still collecting them...

Re: And the Wheel Goes 'Round and 'Round
 

Does anyone know any really quick fixes to traction? We have the 8" skyway wheels and unfortunately put them in the back, so when we hold a tetra alot of weight is taken off the wheels. We ziptied velcro strips to the wheels but they wore out quick. We also cut grooves, which helped. What kind of easily attainable substance could we ziptie on?
If you have any good tractiony stuff on hand, that would be sweet if you dropped by team 1093 at VCU tomorrow morning.

P.S. we also heard that coating them in wd-40 makes them sticky when they dry, anyone tried this?

Re: And the Wheel Goes 'Round and 'Round
 

We used 4 these last year along with a pneumatically activated caster plate which raised our back end a 1/4 inch, which allowed us to have 2wd and 4wd.

Re: And the Wheel Goes 'Round and 'Round
 

About quickly applying traction, last year we added zip ties to our front wheels to limit are traction and in back we zip-tied pieces of pneumatic tubing rapped in surgical tubing to give us more traction. They also acted as cleats to climb the step but they did provide more traction.

Re: And the Wheel Goes 'Round and 'Round
 

The following link show a photo of our wheel config this year. With the belting material donated to us, these wheel will provide all the traction you would want for the powered drive wheels. The photo caption shows the cost advantage as well.


http://www.chiefdelphi.com/forums/pi...10&quiet=Quiet

Re: And the Wheel Goes 'Round and 'Round
 

This year we used the same wheel we have used for the past two years. They are pneumatic 6.75" mountain board wheels. They give the best traction Ive ever seen and being pneumatic you can adjust the pressure to get more/less if you need it. They are really great. My freshman year..wow 5 years ago. Me and a couple of the guys made a "traction-o-meter" haha. we made a box with a shaft that you put a wheel on and then had a string attached to a force meter and found out the force it took to pull various wheels over the carpet. Anyway another good wheel is wrapping conveyor belt material around the wheel with some epoxy and then screwing them or pop riveting the ends together. We used that type for the 2002 game and it seemed to work well. :D

Re: And the Wheel Goes 'Round and 'Round
 

We used 8.5 X 2 inch Skyway Beadlok wheels on a 4WD system and they have plenty of traction. Much more than the kit wheels. It is very important that your wheelbase (distance between front and rear wheels) is less than the track (center distance from side to side) or your robot will "dance" when it turns IF it turns at all.

Re: And the Wheel Goes 'Round and 'Round
 

Two classic methods: teams a) put lots of zip ties on the wheel or b) screw belting onto the wheel.

Problems: With method a), you need to have a lot of zip ties as spares as well as on the wheel, and you don't seem to get quite as much traction. With method b), it's harder to turn the robot.

Team 330 has often used method b), and it works really well. we grind about half the tread off a Skyway wheel, cut a strip of whatever belting we decide to use to length, and screw the belting down. After we finished all the wheels, we cut more belting, as it can get very chewed up.

Other methods include using odd wheels or using tank treads.