Homemade electric motor speed control?

Making a small electric motor is not an expensive and big deal (1st grade physics). But what affects the speed of rotation (or RPM)? How can I reach ex. 6 rpm? I want to make a small watchwinder for only 1 watch, and I don't need ex. 2000 rpm, if you understand. by the way, what do I need to make it rotate both directions (counterclockwise -- clockwise)?

Answer:
Controlling electric motors is all about current and frequency. To make your motor run in both directions, you need a switch that reverses the current. To reach 6 rpm, you're going to need to vary your frequency. Voltage = Current* Resistance, so increasing your voltage is going to increase your current.
http://www.electronics-lab.com/projects/...
http://www.seattlerobotics.org/encoder/2...
http://f-cpu.seul.org/~nico/astromech/mo...
Removing a winding or two will speed it up, but you will loose torque
There are many different types of electric motor you have not stated which type you are making.
The most typical way to control the speed of a DC motor is to control the armature voltage. The speed of a DC motor is proportional to the applied armature voltage.

To reverse the direction to a DC motor one reverses the polarity of the voltage supplied to the the armature.
use a potentiometer to regulate to current. like dimmer switchs?? rotate the switch to your desired speed... count and calibrate your switch with a marker pen. ask you electronic shop which suits you best.

use a 4way switch to make the motor go both directions. or a 6pin slide switch will do. (configuration will varey from manufacturer so use a tester)

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