Power Transfer through spinning axle

[joelgerlach]

Hey guys, first time poster. I just bought an eZee Cadence and love it. I'm wanting to mod the wheels to look like a Tron bike, and I've found several things I could line the tires/spokes with to make it look amazing. However, I think zip tying a AA battery pack to the hub is tacky. And why do that when I have a nice big battery to run the thing?

Here's the problem. I gotta get power into the spokes. Does anyone know the name of the part (or a solution I could use) that would allow me to send power into the wheels? Would it be some metal strips that run along a disc hub? Does anyone know what that part is called or how I might be able to implement it? It'd be great to be able to have those lights draw from the battery and preferably the wire that powers the headlights on the bike.

Thanks!
~joel

 

[amberwolf]

A simple but not necessarily reliable method is to use the brushes out of an old "universal" motor, like from a dead vacuum cleaner or drill or other similar device, and two separated copper strips on the wheel, with insulation between those strips and any metal they are mounted to. Install the brushholders on teh fork legs and set them so they press against hte copper strips around the wheel.

Put + of power to one brush and - to the other, then tap that from the copper strips to your wheel-mounted device.


The big catch is that any road grit or oil or grime or water, etc., is going to get in those brushes / strips and potentially cause problems.

But if you keep it clean, it will work.

 

[joelgerlach]

Fantastic, a great idea. I'll rummage around and see what I can come up with.

Is there a specific name for that assembly that I could also search the web for? I wonder if there are any sealed kits out there that would protect it from the elements.

 

[amberwolf]

To seal it you would have to seal the wheel itself.

If you had a brushed hub motor that you didn't use as a motor, you could disconnect the windigns from the commutator segments, and connect up every other comm segment to + and the rest to -, and you would get an alternating current that you could rectify with a diode bridge and capacitor into DC to run your lights in the wheel.

Or you could modify it so the brush holders are axially offset by the width of the copper strips you'd be placing around the commutator. Using two strips parallel to each other, each wrapped around the former commutator, with insulation between the copper and the ex-comm, the brushes would ride over the strips as the wheel turned the rotor/comm. This would be a relatively sealed unit (though because it still has bearings and axle exits and wire exits it cannot be perfectly sealed).

You could build something similar based on a regular wheel hub, and possibly seal that in some way, too.


Personally, the easiest way I can think of to do something like the Tron lighting effect is to do it the same way they did in the first movie, for all the real-actor stuff: paint UV-sensitive fluorescent patterns on your wheel in the desired colors, and then put UV LEDs on the bottom of the handlebars/seat, inside of the forks/stays, underside of the fenders, etc, pointed at the painted areas. (they used regular blacklights, but we have better lighting tech now )


Another method is to use a clear plastic plate on either side of the wheel that doesn't spin, but is instead fixed in place like fenders are, to the fork. Then put your EL wire or other lighting on that plate, powering it from the pack wihtout the mechanical complications of running thru the wheel. It wouldnt' be rotating lighting, but it would be simpler to build and maintain.

 

[joelgerlach]

Good point. I just researched the glowing strips powered by the lights on the forks and thought that'd be an easier thing to implement than trying to run power into the wheel. What's funny is that there's a lot of potential light projects (like the revolights.com guys) but nothing solid. I've been wanting to have TRON wheels since I saw the first movie.

Thanks for your advice. I think I'll try the glowstrips first. Any recommendations? Maybe I can find a kit out there.

Thanks for your help!

 

[Tench]

Or put one of these or a similar dynamo system on the bike but the other way round so the magnets are mounted on the frame tubes and the dynamo is in the wheel, a non contact solution?

http://www.freelights.co.uk/

Simon.

 

[redhoss]

Try searching for "slip ring". A slip ring is a rotary coupling used to transfer electric current from a stationary unit to a rotating unit. Either the brushes or the rings are stationary and the other component rotates.

 

[joelgerlach]

I wonder if something like this would work:

http://www.ebay.com/itm/2-AMPS-12-C...ltDomain_0&hash=item1e6b1dca66#ht_3718wt_1165