You are talkign about +/- 10 degrees for a rotation right? Not tip/tilt?
I would use a servo & Gearbox, but if you velocity control is really critical, I would go direct drive servo. Stepper will probably not be the best choice for this application because they are not well suited for low-speeds and quick accel/decels. They are good at velocity control, but there is a ripple present. (With a gearbox, you could get away using a stepper, I wouldn't).
The 300mm mirror is a large inertia, meaning for good control, your going to need a large motor. The torque requirement is not high, but as I said..the inertia is. If you can live with the velocity ripple the output of an gearbox gives you (and the gearbox will hold up to the abuse), then you can get down to a smaller motor, but if you truely need excelent velocity stability, a direct-drive servo is the way to go.
What are you trying to do in the application? If scanning/inspecting, also be concerened about wobble & run out. When I first read what your looking for, I thought of a galvo scanner..but usually the mirrors are round and you tip/tilt them.
Cameron Anderson - Sales & Applications Engineer
Aerotech, Inc. -
"Dedicated to the Science of Motion"