Help needed identifying a motor

Thread Starter

leo.leo.leo

Joined Apr 4, 2017
19
I found this motor in my box of parts in a bag labeled "stepper".

The number printed on the top of the motor is 960398-002 07 with a mark that looks like "fa" inside a circle. On the back side, it reads 4315.

It has 8 wires.

Searching google, I get very little information but nothing to confirm that it is actually a stepper motor.

Can you identify it? Should I just assume that it is an 8-wire stepper and approach it accordingly or is there a better way?
Note: I don't have much knowledge or experience yet so it won't take a lot for answers to go over my head.

Thanks!

IMG_0424.jpg
 

Dodgydave

Joined Jun 22, 2012
8,585
Could be a four coil stepper motor, best way is to measure the resistance of the windings for continuity between each other.
 

Thread Starter

leo.leo.leo

Joined Apr 4, 2017
19
The results I'm getting from measuring continuity and resistance don't make sense to me. Probably I am doing something wrong and will try it again.

There is continuity but no resistance between the red, black and green wires.
There is continuity but no resistance between the purple and grey wires.

That's all I found.

Someone else out there on the internet found these readings for this motor:

Screen Shot 2017-06-09 at 3.19.58 PM.png
 

Thread Starter

leo.leo.leo

Joined Apr 4, 2017
19
Hello,

Have you seen this thread?
https://forum.allaboutcircuits.com/threads/stepper-motor-driver.50605/
It mentions the same numbers.

I found this text : IBM 960398-002 CAPSTAN MOTOR Minnesota Compute...
on this page: http://www.computertradingpost.com/archives/CTP_Archive_255.htm

Bertus
Yes, I saw that thread. It's the same motor, I'm quite certain, but there doesn't see to be any conclusion.

For the Capstan motor, I see it mentioned a couple of times but I don't know what to do with that information.

There's another conversation out there from someone with the same motor (same place I found the resistances) where they conclude that it's probably a 9v "brushless" motor but the links don't exist any more.
http://www.cnczone.com/forums/archive/index.php/t-152728.html
 

Thread Starter

leo.leo.leo

Joined Apr 4, 2017
19
I checked again and I am finding continuity on all same wires shown with numbers greater than 0 in the table above. But I'm still only finding 0 ohms resistance.

Edit: OK, yes I was doing something wrong. I get the same readings as above for the ~3 low ohm readings. I'm still not getting a reading for the grey wire so I can't confirm the ~800 ohm readings.
 
Last edited:

shortbus

Joined Sep 30, 2009
7,237
Try turning the output shaft with you fingers. Does it seem to 'cog', like there is a ratchet type movement inside it? It might be a stepper if it does. The 'cogging' is due to the individual magnetic poles in a stepper.
 

Thread Starter

leo.leo.leo

Joined Apr 4, 2017
19
It's possible that the strange readings on the grey wire are down to my inexperience with the multimeter. Or possibly a loose connection. When I have some time, I'll unscrew the case and see what I can find inside.
 

shortbus

Joined Sep 30, 2009
7,237
It's possible that the strange readings on the grey wire are down to my inexperience with the multimeter. Or possibly a loose connection. When I have some time, I'll unscrew the case and see what I can find inside.
The motor case? If you do that don't expect it to ever work correctly again. They are fitted at the factory and don't take well to "repairs" that open the casing.
 
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