# Old six wire stepper motor... Seagate -- Not sure what I have

I have an old seagate stepper motor… I have have not been able to decide on the wiring… I’m betting someone else already knows…

I’ve attached a PDF with a photo… the below resistance pinnout table, and the multimeter doing the test.

******* Red Blue Green Yellow Brown Orange

Red ******* 0.03 0.03 0.015 0.03 0.03

Blue 0.03 ******* 0.03 0.015 0.03 0.03

Green 0.03 0.03 ******* 0.015 0.03 0.03

Yellow 0.015 0.015 0.015 ******* 0.015 0.015

Brown0.030.030.030.015 ******* 0.03

Orange 0.03 0.03 0.03 0.015 0.03 *******

[/table]

I am interested both in what I have here and also how it would, and if it could, work with a http://www.seeedstudio.com/wiki/Motor_Shield_V1.0

Seagate stepper.pdf (812 KB)

Sounds like you have a five phase unipolar stepper. Would work just like a typical, four phase unipolar motor but with one extra phase to deal with.

Your PDF is missing btw.

Well you could also view it as a five-phase AC motor with windings in a star arrangement and the common
point brought out as the yellow wire. You next need to establish the order of phases and look up ways to
drive a five-phase motor (unipolar will be the simplest, but not the best).

Are those values really ohms? 0.015 ohms?

Couldn't it also be a four phase stepper using two center-tapped windings, thus 6 wires?
An ohm meter should help you prove how many winding you have and if center-tapped or not.
Lefty

Hey thanks for all the replies... the PDF is now attached -- thanks for making me realize that hadn't gone as well.
Capital I

Couldn't it also be a four phase stepper using two center-tapped windings, thus 6 wires?

If that was right, why would only the yellow wire have a unique resistance to the other wires ?

His meter is probably reading 15 Ohms per phase with yellow as the common.

retrolefty:
Couldn't it also be a four phase stepper using two center-tapped windings, thus 6 wires?
An ohm meter should help you prove how many winding you have and if center-tapped or not.
Lefty

Not with those measured resistances.

So could I use a pair of ULN2004AN darlington arrays to achieve all five phases?
4 through the first ULN2004AN and 1 through a second? -- seems like that would work?

Well the 2004 has 7 darlingtons, so one package would suffice.