View Full Version : 8" wheelchair hubs and 25 tooth sprockets
11-18-2004, 08:35 PM
We are a rookie team doing a drive train mock up. Last years kit of parts came with 8" wheelchair wheels, hub spacers for mounting, and 25 tooth sprockets pre-drilled to fit the hubs.
My question is ...
Who supplied these and where can I buy them? We are being mentored by team 608 and they had a few, but we need four more for the project we are attempting. (4 sprockets and 4 hubs)
Part #s and supplier would be awesome.
We would purchase spares if a team does not need them.
I could not find them on Small Parts..I think another supplier dealt with this.
We also would like the part # of the flexible motor coupling as well.
Thanks in advance,
E.C.Goodwin Technical High School
New Britain, Ct.
you can get sprockets from McMaster Carr (www.mcmaster.com), MSC (www.MSCdirect.com) Stock Drive Products (www.sdp-si.com) Small Parts should sells sprockets. Granted, they won't be pre drilled, but neither will any of the other ones you buy elsewhere.
11-18-2004, 09:36 PM
During the build season, the plastic hubs were handled by MMH, you can call them at 603-668-1969 and try to explain you rookie situation, if they have some left they might sell them to you. Here is the order form (http://www2.usfirst.org/2004comp/MMH_Ventures_Fax_Order_Form-RevA.pdf), in case you need it.
The wheels are supplied by Skyway, and you're lucky they are official sponsors and even have a toll free number for FIRST teams, 1-800-332-3357. Check Skyway website (http://www.skywaytuffwheels.com/usfirst.htm), just identify yourself as a rookie for the upcoming season and they'll be more than glad to help you.
The sprockets issue was well explained by Cory, you can pay a shop to have them drilled or try to contact a local team - there are a lot in Connecticut - to see if they'll do it for free. This is FIRST, after all. It's insane. You gonna love it. ;)
11-18-2004, 09:44 PM
The BOM says that 6" and a 12.5" wheels were included in the kit.
Generally those, and other wheelchair wheels are procured from SKYWAY (http://www.skywaywheels.com/)
edit: http://www2.usfirst.org/2004comp/Specs/skyway.pdf Hubs and wheels
As for sprockets, 10 and 45 tooth ones were available. Both from http://www.mscdirect.com (http://www.mscdirect.com/) Not sure about the 25 tooth.
Flexible Motor Shaft 13.5" Long, Fits Seat Motor www.grcontrols.com (http://www.grcontrols.com/)
12-13-2004, 01:27 PM
Beware of the weight of the steel sprockets from last year - they have a huge hub. You can get aluminum sprocket blanks at various places(www.jackssmallengines.com) if you have some way to adapt them to the hub. Depending on this year's game, we'll probably try to use 8" wheels and adapt the sprockets.
12-13-2004, 01:47 PM
Actually, if you order the sprockets from McMaster-Carr, you can specify a bore size and they'll come bored and keyed, which is how the FIRST sprockets came as well. Just look for finished bore sprockets.
12-13-2004, 02:27 PM
Do they have any all-aluminum #35 chain sprockets with hub? Or an adapter for, say, a 5/8" bore? I can get blanks with a 1" hole, but they don't have a hub with a keyway.
They won't give me a catalog, and their web site is a bit tedious to use.
12-13-2004, 02:48 PM
You might also want to check http://www.wmberg.com/ for those aluminum sprockets.
Also, for future refererence about those hubs, here is a drawing of them (I don't remember where I got it but perhaps it was from back in the day when Small Parts sold them). Perhaps somebody could make some (aluminum maybe) from this drawing.
12-13-2004, 03:05 PM
I'll check it out. I think I can use the newer wide skyway 8" pneumatic wheels with the keyed hub, then mate a smallish sprocket (say 14 to 16 tooth) and use that as a bolt-on hub/flange to mount a larger aluminum sprocket. That would avoid a lot of steel. Maybe even go-ped or pocket-bike wheels would work.
I remember those hub adapters from 2001 - we used 'em. I don't know if that was a Small Parts special or something from Skyway.
12-14-2004, 06:54 PM
Thanks for the help! We were able to get the hubs, wheels and sprockets together, and mock up a good chassis!
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