Comments on: Is Using An Old Makita Power Tool A Stupid Idea If I Want A Low Voltage Generator?

By: mavis b

mavis b — Tue, 19 May 2009 14:36:17 +0000

Your best shot is a trip to Radio Shack. Buy a 3V DC motor and, if you like, a small 1.5 volt wheat lamp (or any low current lamp) the ‘generator will begin to have a higher tourqe requirement the more the load is increased. The wheel (turned by the water) needs to be efficient, so look for an old 3-4 inch diameter squirrel cage blower wheel (out of an auto motive heater would be great try AutoZone) the rate of water will need to be pretty good to light the bulb so if it is very weak, use a 12V motor and light an LED in series with a 470 ohm resister.

By: Rich Z

Rich Z — Tue, 19 May 2009 14:36:16 +0000

The shaft of a power drill is very geared down from the speed of the motor. That would make it hard to turn. If the tool’s gear mechanism uses a worm gear to get the speed reduction it would be close to impossible to get the motor to move easily.
Maybe a used generator from a small car (or boat, bike, or golf cart) would be a better idea. Try looking in a local salvage yard or on eBay to see what is out there.

By: Mastermi

Mastermi — Tue, 19 May 2009 14:36:16 +0000

Most all electric motors run in reverse (you turning the shaft) will generate electricity. For a hydro device one of the main things you want to look for is the torque needed to turn the electric motor. Some motors (generally the bigger they are) will require more torque to turn that others (a RC cars won’t require much). You may find some are so hard to turn that it isn’t practical to try to turn them using water power without a fancy setup. Other than that you should be fine with pretty much any electric motor.

By: genericm

genericm — Tue, 19 May 2009 14:36:16 +0000

It might work. Can you remove the motor? Then you could just try turning it, and seeing if you can generate a voltage when you spin the rotor (connect a voltmeter or LED to the motor leads and see if you get anything).
Good luck.

By: Al R

Al R — Tue, 19 May 2009 14:36:16 +0000

If the motor has a permanent magnet field it will work as a generator, the voltage will vary with the speed with whitch it is rotated.

By: Anonymous

Anonymous — Tue, 19 May 2009 14:36:16 +0000

I think one of the other answers mentioned the torque problem. In relation to the voltage output the y are directly proportional to each other so if you had a good steady stream , say a garden hose set on JET and could turn the impeller of the generator with it directly at full speed you could possible produce enough power to turn a 555 ic clock into a small light show with a couple of leds..However if your application is one of kilowatts then you better be prepared to have a sizable force stored in the forms of a dam or other potential device..ie water tower…A gear driven drill is propelled by a 1750 rpm motor at approx. 300rpm (this is average) 700 rpm high speed. the reduction is 5:1 . To get a usable voltage out of a drill motor’s motor you have to do this in reverse or turn the armature shaft directly which would be an engineering problem within itself…
I suspect the best advise would be to find a small ..really small dc motor and a good meter spin it by hand and read the output ..if its .01amp at 6v then design you ckt for demonstration around that ..here’s a link to a spot you can see them…http://www.micromo.com/
Your going to have a hard time with the application on the Makita but like the others who answered yes it will work….
Good luck with the project ..From the E..