12 volts??

[unjonharley]

I have a razor scooter motor.. I can get 5v DC when I spin it with a drill motor..

Will the volts go up with more speed??

[oneeyeddick]

hook it up to your side grinder and find out

[Token]

Try a Dremel. See what happens. Best stick a light bulb or some kind of load on it then measure.

[mudpuppy000]

Or set the drill at 1/2 speed and see if the voltage drops.

[Zhust]

Will the volts go up with more speed??

Yes, but you probably don't want to go much faster than 25% over the maximum speed the motor was designed to run at. I'd wager that if it's a 12-volt motor, you'll probably get 12 volts as a generator until you're in the 3x range above the original maximum RPM.

Some "universal AC/DC" motors work as generators. Some electric lawnmowers I've seen use a 150V DC motor with a bridge rectifier (the Black-and-Decker ones that short out the motor to stall it when you let go of the trigger), and they work as generators. I also found a junked 120VAC electric string trimmer and when I ran the motor on my drill press, I could get it to produce usable power above 12 volts -- enough that it seemed plausible to use that as a generator. In general, if a motor "cogs" (snaps to angular positions) it has magnets which makes it a candidate for a generator.

[Bluemandrew]

A Burner from Boston is working on a really impressive project this year called lowRes http://lowres.info/

He's using brushless bike hub motors as generators, as they're built for a lower rpm

This weekend I’ll set it up so I can actually sit and pedal, but I was able to get 100 watts (~13 volts @ 9 amps) without too much effort pedaling with my arms.

Seems promising.