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Author	Topic: looking for parts
perfectcircle unregistered	posted 10-30-2003 12:13 AM I am looking for a hubless rim for a working model. Anyone have any ideas for where I can get that? All the sites I have been to are for hard core engineering stuff. They all weigh 70lbs and can bear a 10000lb load. I need something small and light for a personal vehicle. weighs less than 3lbs and can bear about 300lbs. IP: Logged
DaHui unregistered	posted 10-30-2003 12:45 PM You might look into gokarts if you need something small. I'd say finding something less than 3 pounds is going to be hard to locate in metal. IP: Logged
lawnmower man unregistered	posted 10-30-2003 08:43 PM any hardware store- lawnmover wheels. they come in all different shapes and sizes. IP: Logged
lm unregistered	posted 10-31-2003 12:29 PM hubless rim... please define. do you mean a rim/tire assembly that bolts onto a hub ... vis a viz an automobile tire/wheel? or do you mean hubless, as in the assembly does not rotate on a centerline mounted axle? what is the diameter? width? the thomas register is always a good place to start... IP: Logged
perfectcircle unregistered	posted 11-01-2003 01:25 AM I was looking for something like this: http://www.osmoswheel.com/pages/galerie_photo.asp imagine a rim that spins within the diameter of the wheel. IP: Logged
EINstEIN unregistered	posted 11-02-2003 01:34 PM PC, you're probably going to have to make your own. I doubt there are any "production" level hubless rims, ESPECIALLY in the size you desire. The reason you can only find hardcore engineering applications is b/c the hubless rim is not in wide application. Good luck. IP: Logged
momknowsbest unregistered	posted 11-02-2003 09:06 PM dream on. what you are asking for is likely technically impossible. i want an airliner that can go from London to LA in 2 hours and seats 10,000 people at less than 5 million dollars and only consume 1000 gallons of fuel. yes, you could make money by selling tickets on this aircraft, trouble is you can't build it. marketing request does not equal manufacturing possibility all the time. IP: Logged
perfectcircle unregistered	posted 11-03-2003 02:11 AM momknowsbest- you don;t even know what I want to build and your telling me it can;t be done? your name should be momknowshowtomakecookiesandnothingelse IP: Logged
perfectcircle unregistered	posted 11-03-2003 02:17 AM I put in an iquiry with thomas registry. we'll see what they say.... IP: Logged
DaHui unregistered	posted 11-03-2003 10:19 PM I've seen this before on a working custom motorcycle. No idea how it works or who made it. Now that's really helpful huh?...I'm going to guess that having one custom fabricated will be thousands of dollars. IP: Logged
unregistered	posted 11-04-2003 07:51 PM perfect circle jerk more like it.... IP: Logged
mister unregistered	posted 11-05-2003 02:09 AM Billy lane fron Choppers Inc has one on his bike or try http://www.osmos-wheel.com/pages/prospectives.asp IP: Logged
momknowsbest unregistered	posted 11-05-2003 07:45 AM I need something small and light for a personal vehicle. weighs less than 3lbs and can bear about 300lbs. Well let me know when you find one for less than $200US! I'll buy two. I just don't realistically think you can build such a beast under 3 pounds and hold 3 pounds for a personal vehicle. A bike wheel (that's a personal vehicle) without the tire is around 800-900 grams in the $200 range. These are mass produced by the thousands. They can be lighter but not at less than around $200 each. So for 1350 grams and say under $200US each, you want a hubless wheel. That's why these things only show up on cost no limit vehicles. Some of the photos on that web site are concept models from an ACCD student project. I believe I've seen that car too. I'd be happy to be proven wrong. Given your criteria, I don't think material science has reached the level of cost/performance you want. IP: Logged
lm unregistered	posted 11-05-2003 09:38 PM 300 x 4=1200 (pounds) so, what kind of personal vehicle... . are we talkin' internal combustion sidewalk screamer, or a 5mph golfcart? what diameter and tire size? if you think about it, you CAN design your own wheel assembly, and build the prototype out of masonite and fiberglas and epoxy ... to see if the concept will work. are you going to have to build a tire to go with it? IP: Logged
dadknowsnothing unregistered	posted 11-13-2003 04:23 PM I'll ask why do you want this type of rim? The energy required to turn this type of wheel is much higher than a centered hub arrangement. Which is why I wonder about some of the propose wheel chair applications I've seen. Student projects aside I think the only production vehicle that uses a wheel assembly with an edge ( at the rim) transfer of power is the military spec Hummer. The power to turn the wheels is ridiculous (and so is the fuel economy) but it has better ground clearance than a center hub vehicle. This was the design intent It is because of this poor energy efficiency that Hummers have such flimsy armor/protection (to save weight) and unfortunately why our troops often die in these vehicles. Why do you want to use this type of wheel/rim? IP: Logged
perfectcircle unregistered	posted 11-16-2003 12:09 AM why does it have more resistance. I have read that it is more efficent and easier to move. -pc IP: Logged
perfectcircle unregistered	posted 11-16-2003 12:21 AM I have seen the protorypes from Osmos Wheel. I have also contacted them about getting one. They said they do not actually manufacture them but they license the technology. I do not want to get to specific about what I am trying to prototype. IP: Logged
lm unregistered	posted 11-17-2003 01:09 PM so, it's been eleven days since i last posted... your design should just about be through the prototype stage. is it...? time's a wastin'. IP: Logged
frank unregistered	posted 11-17-2003 04:31 PM The hummer does not use "edge drive" on it's wheels. The wheels are driven centrally through a portal axel arrangement, which is a gear reduction at the hub. This gives a ground clearance advantage, as mentioned. Mercedes Unimogs and the old VW buses used the same arrangement. The reason the hummer is hard on fuel is because it is a big heavy vehicle. I can think of no reason for a wheel suspended by bearings near it's rim to be harder to drive than one suspended at the hub. As to the question at hand, I think you'll have to make your own, and may be difficult to meet those specs, 3 lb weight, 300 lb load. Depending on what diameter you need you might be able to modify off the shelf bicycle rims, or you may have to start from scratch. I think carbon fibre or kevlar might be good materials for something like this. IP: Logged
perfectcircle unregistered	posted 11-18-2003 01:36 AM Frank- this sucks. Why is there not something like this readily available?!? I guess I can try to make one out of other parts. I just got a catalog in the mail from FAG (big bearing making company) Everything in there is designed to roll the Space Shuttle to the launch pad. Hmmmm...maybe instead of my protoype I should start a company that dsigns and builds recreational grade hubless wheels. There seems to be a wide open market with no competition. IP: Logged
bonz unregistered	posted 11-18-2003 10:09 AM An early post referers to a custom motorcycle with a 'hubless' rim. This was working ridable bike. The wheel was built up from a set of helecopter bearings approx 12 inches in diameter. The external bearing surface was bolted to a modified or built up motorcycle rim, and the internal bearing surface was attached to a single sided swinging arm. the ting was driven by belt drive, the rear pulley of which was attached to the rim. There a so picture here. http://www.rideontv.com/episodes/2003Season/CRN8009/hublessbike.html If this is a prototype project and not intended for the road an inexpensive working wheel could well be made up using a similar technique. good luck IP: Logged
way too many wheels unregistered	posted 11-18-2003 02:17 PM i couldn't resist.... http://www.bikerworld.co.uk/gallery/freeshots/June02/thundarr.jpg IP: Logged
frank unregistered	posted 11-18-2003 11:22 PM I can't really see the advantage, other than it looks pretty cool. It doesn't seem like that big a challenge to build either. An outer rim to mount the tire of your choosing, an inner fixed rim to attach to the rest of your machine to, and a number of small deep groove ball bearings running between the two. I can picture it in my head. Should be pretty easy, with a bit of machining, and you should be able to use off the shelf bearings. The thing to watch for with the design I've just described is that if you are planning on high speeds your bearings will be subjected to very high rpms. The advantage I see to using composites, (carbon fibre/resin, kevlar/resin, or good old fibreglass) is that if you don't have machining capability you ought to be able to make up some molds and plugs and mold the parts to shape without any machining to speak of. IP: Logged

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