Hi! I’m pretty new to this forum and FIRST and I was wondering what kind of wheels you guys like to use the most and for what reason.
Thanks in advance
45 has used a urethane compound for our rear wheels the past two seasons. In 2004 we used something like shopping cart wheels and this year we used “doubled up” Andy Mark omni wheels. It greatly depends on the game. We have found our smaller wheels (typically the past two years to be 4-6 inches) to help keep our CG down and power up!
It all depends also, on how you want to play the game. For instance in '04 we did not climb the stairs to get on the center platform, that would be nearly impossible with our wheel set up.
-Kyle
We machined our own wheels from 6" di 2" thick 6061 Aluminum disks and screwed on McMaster Wedgetop incline conveyor belting for the tread. You can’t get much more grippy than that stuff.
As a side note, I’ve noticed that I’d say a majority of robots have wheels bigger than they need to be.
100 has mainly used the 6.75" (I think…I never remember exactly) skyway pneumatic knobbies with the diamond treads over the last 4 years.
Last year on 108 we made our own plastic wheels and glued on some waffle tread, and had them on the two middle sides of the 'bot. We also had 4 ball bearings on each corner.
It all depends on the game. Our team has used pneumatic wheels, omniwheels (both custom built and COTS), and the solid 6.75" ‘wheel chair’ style wheels. Last year when we were six wheel drive using the 6.75’s, we modified the center two wheels by machining a channel into the wheels and gluing in conveyor belt tread for extra traction.
for the last two years in OCCRA we’ve been using 8x2 in wheelbarrow wheels&tires. they weigh a LOT but they are very sturdy. and make sure we keep the cog close to the ground. and they grip just enough to push but not enough to easily burn motors.
We’ve been using 6" solid neoprene rubber wheels for the past few years. They’re about 1.5" wide and are completely flat, but have an incredibly high coefficient of friction.
The only problem we have with them is that if they get dusty, they lose a lot of traction, so we have to wipe them down every so often.
From the beginning to 2002 we used the 8’’ Castor skyway wheels simply because they where easy to use and came in the kit of parts. If I remember right you had to either buy wheels from Skyway or make you’re own because of supplier restrictions most of those years.
In 2003 we made our own 6’’ dual gum rubber wheels and they proved to be competitive to say the least! :ahh:
In 2004 we used the Skyway 12.5’’ Tuffwheels because they came in the kit of parts and yet where high enough to climb the platform.
In 2005 we used two different types of wheels. We made our own gum rubber Omni-wheels for the back of our robot and we purchased 8’’ x 1.25’’ pneumatic castors for the front.
http://www.skywaywheels.com/graphics/pic_caster8x125.jpg
Just adding to his post… those wheels worked great. Here are some pictures.
http://www.sigmacatrobotics.com/images/gallery/albums/14.jpg
Team 57’s trying some new wheels in the off-season.
http://204.2.107.191/good_year_powerkart_racing_tires.htm
They’re go-kart tires. Solid neoprene around an aluminum hub. They’re really gripy, as long as they’re clean, and the rear pair has a hole that mates with a shaft with two flattened sides, so it should be fairly easy to use.
nice thread, its giving me some ideas…anyway
what 1403 used last season was a 5" x 1" rubber wheel from McMaster-Carr, the advantages though a bit heavier were that we could staple teflon to any of the wheels that we wanted to so they could be used to slide around a bit. As well as they had no spokes at all really so were very durable. The wheels generated more than enough friction with the carpet to move around. However for the upcoming season we are looking into a waffle tread, our research is showing that there is some good results with it.
Last year we switched from Treads to Wheels and went with these from Dave’s
http://www.davesmotors.com/store/product1050.html
Aluminum Hubs and they even have the aluminum #45 sprockets attached you couldn’t get any easier, and if you saw the traction in low out of these things on our robot last year there was no question they are super grippy.
We also bought these for a smaller 6" wheel
http://www.davesmotors.com/store/product861.html
Check out these though if you want awesome wheels WITH the provision for a sprocket mount, it doesn’t get any easier. Just add your own conveyor belting to the rim
http://www.davesmotors.com/store/product536.html
Here you go!
http://www.davesmotors.com/store/wheels.html
Wow thanks for all the replies, never knew i would get so many resonds over night!
Just wondering but does everybody use the same shaft sizes? Or… does it depend on the design of the robot or some other reason?
We’ve used 3/8" but only because we drive the wheels and not the shaft.
Does that mean the wheels turn freely on the shaft? And that the shaft is stationary?
We use custom made, open cell skyway wheels. We then make diamond shape cuts on them so we have enough traction on the field.
Correct.
Bearings are pressed into the hubs, and a sprocket bolted to the side, with the shaft mounted through two blocks, rather than having the shaft mounted through pillow blocks, and then the sprocket bolted to the shaft, with the wheels fixed.
What do you people think about
the Multidirectional wheels or
Omni Wheels
Omni wheels are great! If you want lots of traction while using them, then you must design them using the right materials.
In the 2003 and 2004 we built a 4 wheel drive to 2 wheel drive conversion for our robots.
We built these conversion mechanisms so we had better maneuverability and so it was easier to turn.
This year we decided against using them because it took time to deploy them.
So we used two pneumatic tires in the front and two omni wheels in the back.