Ich habe den hier noch nicht ganz zu Ende verfolgt:
http://www.eio.com/public/stepper/0098.html

I have a Stepper motor with ident. number 57SH-52A9E
( 22,5 ohm, 0,9 deg).The logo of manufacturer is a triangle of arrows.

I was looking for info about a similar motor that I have. I am pretty shure that it might be from dpmotor.com