hi i am trying to figure out the best way to make a small electric motor go foward then reverse on a constant on position. (like a printer would go back and forth). how would i go about doing this?

 

You will need to use what is called an H-bridge.

hgmjr

 

Hello,

In a printer a steppermotor is used.
By changing the sequence of pulses to the motor the direction can be changed.
On this page from the EDUCYPEDIA there are links to sites and documents about stepper motors.
http://www.educypedia.be/electronics/motorstep.htm
On this site there are more pages with links.
Motor and generators: Brushless DC motors Motor AC Motor-Synchronous Single phase AC motors Generators Motor DC Robot Stepper motor Generator: asynchronous Motor overview Servomotor Stepper motor drivers
Greetings,
Bertus

 

Have you a specific application for your motor in mind?

hgmjr

 

And/or have you a specific motor in mind for your application?