Many of the motors that look like stepper motors in laser printers are actually three-phase brush-less DC motors. These look like stepper motors, but are intended to be used differently, controlled differently, and serve a different function. Like stepper motors, they have a permanent magnet rotor surrounded by coils of wire.
They typically are used in applications that require a definite rotation speed, rather than a definite position -- velocity rather than location. They create feedback to their controlling board via an encoder.
Differences include having a smaller number of poles, and possibly having three coils rather than two. I suspect that the magnetic field profiles of the poles may also be different, since the primary design purpose is not to sharply define the restoring torque curve for a small deviation of the rotor from a rotational position.
If these are the type of motors you have in hand, you won't find them very useful for a 3D printer motion control system. They are great for any form of continuous movement where position isn't critical -- maybe wheel motors for robots or for peristaltic pumps on your automated drink mixer.
You may ask on what experience I speak. I have done tear-down analysis of several laser printers by different manufacturers.