So after having watched many robots this season i was alarmed by how many pneumatic tired robots were out there. I love the smoothness of the ride on these robots and i was wondering where teams like 1114 got their wheels… i would love to find some in the 6 inch range…
I’d be game for some in the 4" range :]
I know that 118 made their own (but big ones). That requires some serious machines though.
http://www.harborfreight.com/6-inch-replacement-dolly-wheel-97183.html
Try these, they’re a touch wide but they are 6 inches.
1114 got their tires from McMaster, and I believe fabricated custom hubs.
I think that one has a 6" rim, and a 12" diameter tire.
McMaster has a pneumatic caster tire:
2717T51
Pneumatic Wheel for Casters Gray, 6" X 2", 3/4" Axle, Ball Bearing, 200# Cap
In stock at $19.27 Each
It has a split rim that would require some sort of adapter or custom split rim (as mentioned above).
You don’t want to know how many of those 330 wore down between 2005 and 2007. Fortunately, the tire is available separately. (They were our center wheels in a 6WD.)
We did have a custom adapter made in at least one of those years; ShaneP designed it, IIRC.
Another good option would be skyway’s 8"x 2" caster wheel (they really measure around 7.5"). They have light weight plastic hubs, 7/16 bearings, and a 4 lug bolt pattern that can be adapted to standard AM sprockets with a bit of drilling and a few standoffs. Also a wide range of tires are available with different material and tread options. I believe both 2753 and 469 used them this year (correct me if I am wrong on 469).
http://www.skywaywheels.com/products_004.htm (all the way at the bottom of the page)
Actually, we used these this year as well as 2006… I know a few other teams that like them too. Rockstar hubs with a custom sprocket adapter…
http://www.mbs.com/productcart/pc/viewCat_mbs.asp?idCategory=43
We’re a big fan of pneumatic tires, and have used pneumatics tires on our robot for 4 of the last 6 years. (Didn’t have an application for them in Lunacy for 2009, and later wished we had used pneumatics in 2007!) We’ve also used pneumatic tires for ball-manipulation mechanisms. (Shooter wheels in 2006 and a “roller claw” for the trackball in 2008.) Being able to adjust the air in the tires or change tread patterns provides for essential “tweaking” opportunities to get a manipulator to work just right.
Our preferred supplier for pneumatic wheels is Skyway Wheels. Skyway used to be the kit-of-parts wheels supplier for FIRST back when pneumatic tires came in the kit of parts. They have wheel options available with keyway hubs (which are very easy to use) and also with bolt-on mechanisms that make interfacing to shafts easier. See http://skywaywheels.com/products/hubs/index.html or http://skywaywheels.com/products_007.htm
Over the years depending upon robot needs, we have used Skyway’s wheels for 6", 8", 9", and 12" tires. Either smooth or lugged treads can be chosen for tires to fit most of their wheels. If you are looking for other tread patterns than the ones that Skyway provides, most “wheelchair scooter” companies can offer a wide selection, although prices tend to be high for wheelchair scooter tires, as they cater to a medical market and expect insurance to help with payment. The Skyway wheels are incredibly durable – despite loads of abuse, we have never had a Skyway wheel break; we can’t make this same claim for the non-Skyway wheels we have used.
Check out the “FIRST Robotics” box (even though it is old) on the Skyway wheel home page: http://skywaywheels.com/ I would highly suggest giving them a call (rather than email) and asking them to send you their discounted price list as a FIRST Robotics team. Bart Weems is the sales manager in charge of FIRST-related sales - he is very knowledgeable, helpful, and wonderful to work with.
Similarly, if you are looking for tires from medical supply companies, let them know you’re from a robotics team and ask them for partial sponsorship – major discounts are often available!
Skyway Wheels on our robots can be seen in the following images:
http://www.chiefdelphi.com/media/photos/35535
http://www.chiefdelphi.com/media/photos/35102
http://www.mechanicalmayhem.org/teamhistory08.asp
http://www.chiefdelphi.com/media/photos/30818 (Note drive wheels and roller claw)
http://www.chiefdelphi.com/media/photos/30299
http://www.mechanicalmayhem.org/teamhistory06.asp
http://www.chiefdelphi.com/media/photos/23474
http://www.mechanicalmayhem.org/teamhistory05.asp
The “knobby” pneumatic tires we’ve used in 2008 and 2010 are incredibly grippy, yet still relatively durable. Being able to adjust the robot handling by changing the air in the tires is very helpful! (Talk to somebody who drives autox Autocross - Wikipedia or drag races for great advice about how to tune tire pressure!)
How did you drive them… i could see tapping them and using a lockring like on a fixed gear bicycle, but any advice?