Stereo & Electronics - reducing speed/torque on 12vdc motor

im looking to reduce the speed and torque on a 12vdc worm drive motor i have. not so much the speed but this thing has 10 times more torque then i want. i already paid for and have 2 of these things not realizing how much power its got. does anyone know how to figure what i need to reduce its power? im thinkin rheostat or resistors like a blower motor in a car. but im not sure what values to start with. all i need this to do is open a bottle. well one on each bottle i want opened :D but at the rate its going it will probably unscrew the valve from the bottle after it bottoms out!

forgot to add. i dont have any specs on the motor except for output is 60rpm. its a siemens motor but of all the markings i cant find anything that leads me to specs. about 16 gauge wire on it

see what happens if you drop the input voltage down to say 6v. You could make your own, but im sure it would be less trouble for you to just buy one(voltage step down unit like this (http://www.chevsofthe40s.com/detail/17971.html)), try it and return it. If 6v make it go too slow, step up to 9v, etc. If its still too fast at 6v, you may be SOL.

This gets tricky. You may want to look for a gearmotor for your application. They are built with a transmission, which allows you to more precisely select speed and torque.

You should be able to do it with a current limiter, but perhaps a better approach is using an appropriate motor to begin with.

Lowering the voltage is going to slow the speed - period.

Lowering the voltage is going to slow the speed - period.

Not if the motor will only run on a certain voltage level. i.e. between 10-14volts.

I will most likely have to get a different motor or make a clutch and limit switch setup for this one. even hooked up to two AA batteries this thing has a ton of power. it doesnt move under the power of 1 AA. thanks guys. BTW radio shack doesnt have shit as far as this stuff is concerned. I get more and more disappointed every time i go in there.

Yep, radio shack is not what it used to be.

Not if the motor will only run on a certain voltage level. i.e. between 10-14volts.

It will still slow it.

it doesnt move under the power of 1 AA.

That was the point i was making. Under the threshold voltage and no go.