DangerToMyself:
Why use a stepper? It's what is available at the time without additional purchases.
That isn't an actual reason to use a stepper, its a statement that you thought it fulfilled your (unspecified) requirements.
Scale? Rather small. Talking shaft sizes of 6mm.
Speed .... Very slow. It will take 30 minutes to go from one stop to the other.
Ah, so this is the real reason for wanting a stepper, namely needing motion control (ie position
control)
Accuracy... Not all that important. As long as it stops/starts from close to physical stops. And rotates smoothly and at a steady pace.
"Not all that important" - meaningless to me, "close to" - meaningless to me
Torque .. A little is necessary and the motors available are geared up a bit.
"A little", "a bit" - again meaningless to me. Motors are usually geared down, not up, do you mean
up?
Try answering with actual numbers and measurements for the torque and accuracy - you didn't
define "smoothly" or "steady", so its impossible to know what you actually require. One thing steppers
don't do is steady, they move in steps, so the question is "how steady" - numbers again are required
to know what you mean.
If you don't know how to get the actual numbers you'll have to explain the mechanical setup
in full, masses, lengths, mechanism etc, so its possible to calculate the torque and understand your
smoothness/accuracy requirements.