Help identifying electric motors/servos :S

Hello all,

I have got some motors (sorry, don't know exactly what to call them) I have been trying to find specs for. From my limited knowledge they are stepper motors but I don't know why they have so many wires.

I figured this would be the best place to come looking for advice.

They came out of an old SUN SL3000 tape library robotic arm. I've been trying to find some/any information on them but for the first time my google skills have come up short.

Can anyone identify what these are, what their specs might be or at least point me in the right direction as to how to find out myself?

I don't want to go throwing them out if they are going to be useful for something or to someone.

Thanks in advance.

I will link to the images as I can't attach them.

Looking at a handful they all seem to be basic servo motors (motor plus encoder), so I'd starting googling the encoder part numbers and checking out the motor windings. Very nice.

Thanks MarkT,

This has pointed me in a little better direction. I will see what I can come up with.


The three lines going into the motor body are probably supplying a 3-phase static field. The black plug assembly probably carries a dual phase drive signal, the phase relationship and frequency difference between those and the static field determines motor drive direction and speed. The remaining connections probably operate an encoder device.

Lots of 'probabilities' so not much help.

They may even be "selsyn" type motors