Is anyone even working on a costing hub/clutch uni? I mean I can totally understand if they are being developed by someone, and they are hard to make, ect, ect. But I would personaly spend a great deal of money to beable to coast down into a half pipe, the possibilities that would open up for street, and downhill unicyclist, are emense! I’m personaly suprised geared uni’s came before coasting uni’s (with a clutch)
Now I know about the coasting uni made by team SWAT I belive it was. But that is not what we need, we need to beable to ride backwards, forwards, then pull in a clutch and coast as we please. My personal idea is that we use a system much like that is in a bicycle, where you can pedal forwards but not back, but it also has a lock so you can pedal in both directions, the lock will be permenently “on” and as you please you can pull it loose with a clutch lever, this way you can still pedal forward to pick up speed, and then use the uni as a BC wheel, then once you’ve slowed enough you can catch your pedals back up with the hub, and if your not holding the clutch it will automaticly snap back into a locked position.
This will also create three peices to a uni, that will replace the single peiced hub, you will have the new hollow hub, axle, and clutch mechenism, its a pretty simple system to figure out, but I think the mechenism should be on the side of the hub, and hold onto the axle via splines, so this way it can be easily replaced if its to break. I dunno hit me if you think i’m stupid, but yeah KH, Bedford, koxx, Qu-Ax, I don’t care who someone please just atleast make a prototype. I’d be happy just seeing someone use one.
Hmm, interesting project. I might make one, being as I am getting a 9x36" milling machine in 2 days, and my boss just gave me a large amount of 1/2" and 3/8" 7000 series aluminum plate, along with plenty of stainless tube and bar stock. My only issue is I think the amount of work required to make an effective clutch hub. The only way to really make on is to use friction clutch plates, since it’s unridable to suddenly be in gear, and friction clutches are easier to make and more effective to run (less precision required during machining).
As for the design, i was thinking a double set of clutch plates on each side of the flanges.
As for the actual manufacture, i think it’s important to point out that making one of these hubs is a big endeavor, not just something you throw together in an afternoon. If you really want to see one made, make it out of wood and then bring it to a friend with a cnc mill and ask him or her to make it.
Of course unicycles evolved in the manner they did, though! Imagine learning to initially ride on a coasting unicycle! Unicycles evolved from penny farthings, so unicycling has followed the logical progression.
Friction clutches are good, but they have inharent problems clutch plates wear out. Although they can be replaced, and thats not to say that any other clutch system wouldn’t wear out over time with strenious use. But the second problem would be slipping, which is something to contened with.
I don’t know of other ideas out there, and someone elses idea could put mine to shame, but more or less my uni when the clutch is pulled in would ride like the one team SWAT made, or in other words it would ride just like a bicycle forward is hunky dory, but backward is a no go. And the lock, wouldn’t reangage until the axle (which is spining freely) catches up to the hub. The alternative would be to get rid of the automatic catch mechanism, (less parts) and just trust someone isn’t stupid enough to put something in gear while coasting, and would wait until the axle has caught up, (you would beable to feel it just like on a bike when it does.)
“cyberpunk” <cyberpunk@NoEmail.Message.Poster.at.Unicyclist.com> wrote in
message news:cyberpunk.1nkfsk@NoEmail.Message.Poster.at.Unicyclist.com…
>
> Friction clutches are good, but they have inharent problems clutch
> plates wear out. Although they can be replaced, and thats not to say
> that any other clutch system wouldn’t wear out over time with strenious
> use. But the second problem would be slipping, which is something to
> contened with.
>
A magnetic clutch might be feasible. This would require power input
though, but would be a neat option if it could be made to work.
I never rode with one when I did ride two wheels, but what you’re talking about kind of sounds like a BMX freecoaster hub. Only the main problem with that is it’s primarily for flatland (which I rode street–I’ve seen quite a few riders do so with one, though). So when the bike starts rolling backwards for some tricks, you just move the cranks backwards until the clutch enables you to coast in reverse (without the pedals/cranks moving). I think there is a little pedal slack in a hub like this, and I’d imagine so because of the clutch engaging/disengaging.
But what you need is a direct-drive hub that works like that going forwards…
This probably doesn’t help, but I didn’t know if you’ve heard of a freecoaster before.
OH NO! A part of a unicycle wearing out?! Whatever will I do?! Such a phenomenon has never been witnessed before, except with cranks, hubs, tires, pedals, inertubes, seatcovers, handles, seatbases, spokes, and rims. Honestly, so what if something wears out? Tires need replacing every 6 months or so (less for some). As long as you design in the ability to replace the clutch plates, there shouldn’t be a problem.
Not to mention, the 14x40" lathe at my shop has been running for 47 years without needing its clutch plates replaced. As a matter of fact, they’ve only needed adjustment every 15 years or so. A metalworking lathe is much harder on clutch plates than a unicycle is. You can just adjust the plates for wear when they get loose.
As for slippage, simply make it so the plates can handle far more torque than the cranks. that way the plates only slip when the cranks bend, actually acting as a safety.
Pedalling in a freewheel is very difficult on a uni, and if you consider someone stupid for not engaging the gear at the right time, maybe you should adjust your standards.
A quick google search turns up quite a bit of information on magnetic clutches. Rimtec has nice explanations of their various magnetic clutches.
The Rimtec advertising claims that magnetic clutches are maintenance free and can be hermetically sealed. It seems to me that a clutch that disengages the cranks from the hub would be nice if it also engages the cranks to the frame at the same time. With this feature, a magnetic clutch could also double as a magnetic brake, though I don’t know what long term effect that would have on the magnets themselves. If the tension clutches at Rimtec are any indication, magnetic clutches may be able to absorb braking forces for a very long time without problems.
Thank you Naomi for this excellent suggestion! I had never read up on magnetic clutches before, maybe I can acquire one for testing purposes.
“shapr” <shapr@NoEmail.Message.Poster.at.Unicyclist.com> wrote in message news:shapr.1nluy2@NoEmail.Message.Poster.at.Unicyclist.com…
>
> A quick google search turns up quite a bit of information on magnetic
> clutches. ‘Rimtec’ (http://tinyurl.com/8fj3j) has nice explanations of
> their various magnetic clutches.
> The Rimtec advertising claims that magnetic clutches are maintenance
> free and can be hermetically sealed. It seems to me that a clutch that
> disengages the cranks from the hub would be nice if it also engages the
> cranks to the frame at the same time. With this feature, a magnetic
> clutch could also double as a magnetic brake, though I don’t know what
> long term effect that would have on the magnets themselves. If the
> tension clutches at Rimtec are any indication, magnetic clutches may be
> able to absorb braking forces for a very long time without problems.
>
> Thank you Naomi for this excellent suggestion! I had never read up on
> magnetic clutches before, maybe I can acquire one for testing purposes.
>
Don’t know anything about Rimtec, and don’t even remember the brand name
of the mag clutches I was involved with, but they used magnetic dust
rather than specific "bar " magnets . We used them as both clutch and
brake, although in our application the braking effect was quite evil, in
that it had to stop everything within a few milliseconds. ( we had a stop
go cycle of 20 milliseconds ). These clutch/brake units were hammered day
and night for years, and few ever exhibited problems.
They were used to provide the motion for the paper on continuous stationery
computer printers, as used mainly on big mainframe system.
These could print up to 2000 or so sheets an hour and the clutch/brake had
to stop the paper whilst it printed each of the 60 or so lines per page.
Should at least give you an idea of reliability. Suitability: you will
have to decide yourself.
I actually never saw the multi-pole magnetic clutches, but I have seen the dust clutches, although I will admit I wasn’t aware of the dust clutches insane reliability. But regardless of that, I don’t think to many people want to carry a powersource around when they unicycle, just seems like a little to much. But personaly I think magnetic clutches are a great idea within a uni, although theyd have to be permanent magnetics, insted of electromagnets. I havn’t had a chance to check out the magnets at the given site in great detail but they “Seem” to be permenent magnets, the only problem I see though, is that a permenent magnetic clutch might need a substantial amount of room to disengage, and therefore take up more space on your axle, making your feet further apart, i’d like to see the whole clutch system within a two inch enclosed cylinder, and I think it can be done.
Well clearly most people don’t want to carry a unicycle with a clutch, either. Otherwise they’d already exist. Honestly, just fit a battery in the spokes, it wouldn’t be hard.