AirPax K82416-P1 Stepper Motor, 8 Wires, How to Use?

[pax_electronica]

Hi,

I found this motor in a spectrometer with a driver board. The controlling software and hardware are long gone. I would like to revive the instrument by skipping the original driver and driving this motor using Arduino and associated driver modules.

The motor seems to have two sections, each section has its own red, black, grey, and yellow wires, 8 wires total. But I am not certain it is a "standard" 8 wire stepper motor. It also has gear reduction inside, allowing for slow, fine rotation angle control. I searched the web but only find this: Two Airpax k82416-P1 step motor Labview Arduino control - YouTube

I believe the original drive system is called Compudrive, made in the 1980s.

Here is a picture of the motor:

[jremington]

It is almost certainly intended to be used as a unipolar motor with four windings and a common lead (4 winding ends connected together to V+), but can be rewired to use as bipolar.

This PDF file suggests that the K82xxx-P1 series is intended for 5V operation, but if you wire two pairs of coils in series, it would work as bipolar on 12V. It will take some experimentation to determine the polarity of the various windings, and proper step sequence.

This web site describes such 8 lead motors in detail.

Measure the resistance between all the wire pairs to confirm the four winding hypothesis.