seeking slip(ring)age

Could you just put flashing lights on the frame in line with reflectors on the spokes?

jsw

Reply to
Jim Wilkins
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The lights are only on when the scooter is moving.

They might be done with something like a "shake light"-type generator near the hub. That avoids needing batteries. I'll have to find one and check it out.

Reply to
Hactar

Good idea. That would make the commutator rather less complex. I would need a voltage converter and capacitor (to smooth out noisy conduction) on each wheel though. Hmm, I wonder if I'd need a contact on the inner end of the axle, or if using the chair frame is good enough. Multimeter to the rescue!

Yeah, but I have to consider the chance of it catching on other stuff when the wheel's removed (eg when it's put into some car trunks). That restricts me to things that are either springy (so they snap into the correct position) or really sturdy.

Reply to
Hactar

This is the look I'm going for:

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Reply to
Hactar

Bad idea. Current flow through wheel bearings = unreliable bearings.

Suggest that you mine 'inductive coupling' ideas from a worn-out Phillips Sonicare ultrasonic toothbrush.

Sorta like:

--Winston

Reply to
Winston

Ignoring all the battery charge feedback stuff, that's essentially my rotary transformer suggestion.

Reply to
Pete C.

OK. I thought you posted a "commutator". This is a switching device. "Slipring" would be more appropriate.

The generation would have to be switched on when going downhill and the little bit of energy for a few LEDs would never be noticed by the human but.....

I have misread your request and it looks like you just want a way to get power to lights on the wheels from batteries on the mainframe. My guess is the brushes on the sliprings would cause more friction than a magnetic induction system to flash and flicker the LEDS, depending how many, of course...LOL

A few magnets on the chair, coils, diodes, capacitors and LEDs on the wheels and you would have it...wired for sound! Ohh yeah, you mentioned about them not lighting unless you move so I guess that is out.

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Reply to
Josepi

I think people did not understand your device mentioned. I have never heard of that.

More info?

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Reply to
Josepi

The axle would have to act like the transformer core then??

If so he would have to wind a pickup coil on the axle bearing inside the spokes of the wheel. Could be done but would be tedious.

That would be cool. Bearing may buzz a bit at the wrong frequency. It shouldn't with body weight on it.

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Reply to
Josepi

Yes, both would be rotary transformers. I think the phrase was too 'scary', though we both know it is the right approach.

:)

Heat up some milk. Mix in bacteria and fungus. Drain the mixture for 18 hours. Inject liquid mould. Put it in your basement for five weeks until it starts emitting the unmistakable stench of ammonia produced by bacterial um. 'waste products'.

Slice it into little tiny wedges and sell it as Brie cheese for nine bucks each.

Yummy Yum Yum! :)

--Winston

Reply to
Winston

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> The lights are only on when the scooter is moving.

Not too long ago the hot fad was liquid-filled rubber balls with bump switches and flashing LEDs inside them. I was in line at the drugstore, and some kids were playing with them, and I asked kind of in general, "So, how do you replace the batteries when they wear out?"

Nobody knew.

Cheers! Rich

Reply to
Rich Grise

If you have pneumatic tires and you can dismount the rims from the spokes you can make up little insulators to fit around the spokes to electrically isolate the rim from the spokes. Now all you would have to do is make a spring loaded brush to contact the rim and one to make contact with the hub and then you would be in business. (Just stay out of deep puddles of salt water) one side of the lighting could then be attached to any spoke, and you could tun a thin strip of copper through the valve stem hole and make that your second connection.

I think if you went this way it would be best to do one spoke at a time and that way your wheel would not get too far out of whack as you can re-tighten one at a time. Alternatively you could just take a spare set of rims to a bike shop and let the wizards do it and true the wheels. (Probably better than they come from the factory.)

Of course if the rims are anodized aluminum that might not conduct very well and you would have to get below the anodizing for it to work.

How much space is there between the spokes at the hub? If you had enough room you could slip a soft battery case using either AA or C cells that were sewn into a strap that could be fastened around the inside hub with Velcro. Out of this a small switch, plug for the lights and and a charging jack would come out to hook everything up. You might also build in the switch that could detect motion and if static for more than a minute or horizontal it would shut off. Or you could mount the batteries parallel with the spokes fastened between plastic disks. What I am thinking about here is two flexible plastic disks 6 to 10 inches in diameter. Each disk would have a hole in it the same size as the wheel hub and a slit from the hole to the outside edge. The batteries could be attached with zip ties through slits in the plastic and then you could feed one side of the slit in between the spokes and wind it around so that it would be between the spokes. A couple more zip ties to fasten this assembly to the spokes and you are in business.

I like the plastic disk idea the best as it would be cheap and easy to make. You might skip the switch altogether and just use a plug that you could either plug your lights into or unplug the lights to shut it off or to plug in the charger.

Good luck with the project.

Roger Shoaf

Reply to
RS at work

A few mm. Lessee: there are 18 spokes per side, one every 5 degrees. The spoke ends are 1 7/8" apart. A right triangle ABC (B=center) with |AB|=15/16" and angle B=5 degrees has tan (5 deg)=|BC|/|AB| so |BC|=|AB|*tan(5 deg) =15/16" * 0.087488664 =0.082020622" =2.1 mm

I could get a better estimate by using a more accurate measure instead of a plastic tape, and by dividing the wedge between the spokes into two right triangles, since |AB| = |BC| really. But that's good enough.

That's pretty much the way it is now, and what I was trying to avoid.

Well, sometimes I want to keep the lights on, even when I'm stationary.

Not quite seeing this. When I remove the wheel (it comes straight out, and the axle comes with it), where are the batteries?

The battery holder I'm planning on using is a 6V flashlight, so the switch comes free. I figured out voltage conversion and power transmission, so I think getting the power to the wheels is the only problem left for which I don't have a solution. Several good ideas have been proposed. My geeky nature likes the circular transformer, but I don't know how I could get the tolerance close enough to make it efficient, and still make it resistant to getting moved when the wheel's off and it's in a trunk. Also, it sounds like a lot of work.

Reply to
Hactar

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