Stepper motor from printer help

Hi,
im trying to use a stepper motor from a printer and the stepper motor example doesnt work. its bipolar i think as it only has 4 wires.
the only marks on it are mitsumi stepping motor M42sp-7.
Any ideas?

this may help
http://www.sscnet.ucla.edu/geog/gessler/topics/steppers.htm

How are you driving the stepper motor ?

Are you powering the motor with a seperate powersupply ?

If so, did you remember to connect the powersupplys ground to Arduino's ground ?

I have tried it without a separate power supply but not home tonight will try tomorrow night after school
Thanks for the help.

Stepper motors draw a lot more current than Arduino can supply, so you really need an external power supply AND some other stuff like for instance an H-bridge to drive the motor (if you want to drive it both forward and reverse) Otherwise theres a good chance you will damage the Arduino board.

if i dont want to use a h bridge can i still drive it with external power if so how?