I have a bunch of stepper motors that I've harvested from floppy drives. They have a series of numbers on the back, but no brand name - and the numbers do not come up in internet searches. Does anyone know how to get datasheets for such stepper motors?
They are pretty standard, in that the arrangement of the leads will be one of two types. I don't know if they use standard color coding, but it is relatively simple to figure it out.
Thus you can very easily hook one up and try it. For a lot of playing around, that's good enough.
Obviously, the differences are mostly mechanical. How much load they can turn, how many degrees each step advances the shaft. If you're scrounging you basically use what you have, so not having the data isn't a big impediment. Hook one up, and step it, to see how the steps go. If you looked over the drive before you took it out, you might have gathered something about the load you could put on it.
That is often important, you can gather information from the equipment you take parts out of. The IC that was driving the stepper might have been a common one, and it's datasheet would provide specs, and that would give an indication of the sort of current the motor would required. For that matter, if you can find the datasheet for the IC, then its pinout would likely be helpful in figuring the wiring to the motor.
Too late for that, but it is pretty useful when taking parts out of equipment. Sometimes it's even better to keep things intact, until such time as you can use the parts, because you can extract this sort of data from the board, and sometimes the peripheral parts are useful too.