8 Wire Stepper

I have read many posts on 8 wire steppers. From what I have read, 8 wire steppers have two coils. I have an ohm meter to determine the coils, but how do I determine which leads to connect for parallel or series connections. I know I can just use two coils and run it as a 4 wire stepper, but how do I know which four to connect other than trial and error. I did find one Youtube that did all this with an O-Scope, but I don't have one of those and really don't want to spend a lot of money for just one motor.

The motor is a Dansa DA299-H8. The Plackard has the following information: Phase Current: 2 Amps Holding Torque: 2.2 N-m Step Angle: Bipolar 1.8 deg 2 Phase Stepping Motor.

Wire Colors: Red Red/White Blue Blue/White Green Green/White Black Black/White

Any help greatly appreciated.

John

8 wire steppers have [u]4 coils[/u]. They may be connected in many ways. See Jones on Steppers.

Basically a 8 wire stepper can be configured as a 6-wire or a 4-wire motor (series or parallel). Thus it can be driven unipolar or bipolar (with two possible impedances). Its a more flexible arrangement basically.

To wire it correctly without a pin-out you need to know the phasing of the coils, which cannot be determined easily - a 2-channel 'scope would be one way, or experimenting with the 4 pairs with a multimeter in AC voltage mode and turning the shaft.

Hi,
The colours of the leads will help with phasing.

Wire Colors:

Coil1 Red (start) Red/White (finish)
Coil2 Blue (start) Blue/White (finish)
Coil3 Green (start) Green/White (finish)
Coil4 Black start) Black/White (finish)

Some wiring configs
Stepper8wire.jpg

Tom… :slight_smile:

TomGeorge:
Hi,
The colours of the leads will help with phasing.

Wire Colors:

Coil1 Red (start) Red/White (finish)
Coil2 Blue (start) Blue/White (finish)
Coil3 Green (start) Green/White (finish)
Coil4 Black start) Black/White (finish)

Some wiring configs
Stepper8wire.jpg

Tom… :slight_smile:

Tom,
Thank you. Sorry it took me so long to respond to everyone, I lost this thread somehow. If I connect the motor as indicated in the left figure (series) and test with led, the led will not light. If I change the wires from red to green in the diagram, I can light the led. And when I check resistence it is about twice the resistence of each coil, if I wire as in right diagram the resistence ia about 1.5 which according to my calculations would indicate a parallel connection. Now the question I have is what if I reverse the connections. For example in the figure you provided, if instead of connecting red/white to blue I connect blue/white to red. What will be the result. Resistence would not be different, but what would happen electrically when I try to power the motor?
Thanks again

If the current in each winding is opposite, no magnetic field, you just have a heater.

If the currents in each winding add up, you get magnetic field, it works.

Try applying power in various combinations and see if the motor resists turning, that will tell you if its the right way.

MarkT:
If the current in each winding is opposite, no magnetic field, you just have a heater.

If the currents in each winding add up, you get magnetic field, it works.

Try applying power in various combinations and see if the motor resists turning, that will
tell you if its the right way.

Mark,

I did some experimenting and found the following. The coils are all wired with one end solid color, the other end striped. I found the Red and Blue wired coiles are on the same side, and the Black and Green are on the same side. I found this by connectin red and red/white to one set of outputs and black and black/white to my other outputs from my controller. The motor turned with all the combinations.
My next attempt was to connect as TomGeorge suggested above. Unfortunately this fried my controller. So I tried the same connection and connected an led to the red and blue/white wires. Turned the motor shaft and nothing. The led would not light. I reversed the connections and still no light. So I connected red and blue togethert and connected led to red/white and blue/white. Now I got an led to light up when I rotated the shaft. Tested the resistence and it was twice the resistence of a single coil.
Next I connected a new controller up and tried to run the motor. Ran fine. At this point I had blue and red connected together, blue/white and red/white connected to one side of the controller and the black and black/white to the other side of the controller.

Next I connected the red/white and orange and the blue/white red wires. That should give me a parallel coil arrangement. Tested the resistence and sure enough about half the resistence of a single coil. Connected the wires to the controller and it ran fine.

My guess is that the coils are wired with solid colors at start and stop of the coils as in the attached pdf file.

DA299-H8 Coils.pdf (16.8 KB)

Yes, thinking about it, if you connect a stepper driver to coils that cancel each other out there is very little inductance and the driver will see a pretty hard short circuit and over-current.

Thats why I'd test with a simple bench supply first to make sure that doesn't happen.

MarkT:
Yes, thinking about it, if you connect a stepper driver to coils that cancel each other out there is
very little inductance and the driver will see a pretty hard short circuit and over-current.

Thats why I’d test with a simple bench supply first to make sure that doesn’t happen.

Yea, that;'s what I should have done. Oh well, at least the Arduino is OK, and I now have a nice motor to use for a project I have in mind. And this is a big motor, half the size of an 1/3HP AC motor, so should give me all the torque and speed I need. I need speed more than torque, so will wire it in parallel.

The speed and torque won't change by wiring it series or parallel. Its the same motor with the same windings each carrying the same current.

However the driver current and supply voltage will have to change to match the winding setup, so for a given supply voltage parallel will offer more speed.

MarkT: The speed and torque won't change by wiring it series or parallel. Its the same motor with the same windings each carrying the same current.

However the driver current and supply voltage will have to change to match the winding setup, so for a given supply voltage parallel will offer more speed.

Thank you for the clarification. I this application speed is the primiary concern. I will need it to run abourn 300RPM max for one or two minutes, then stop. So I am thinking parallel will be my best bet.

sanyo denki step.motor 103g7702257 ....8 wires..i bought it from secondhand stalls...as i searched it on google about its datasheet and wiring connection and compstible driver with Arduino Uno.yet not successed in it... I need some guidance and help to find a way. 1- what driver should i use? 2-can i use this step motor in curtain rolling up and down? In home automation system.

Determining the pin-out of an 8 wire motor is tricky - you have to identify which of the 4 windings belong together, and what their relative phasing is.

The best way is to pass live current through each winding in each direction, after first passing current through a given fixed winding in a given fixed direction.

if the motor moves, the winding you chose is either the wrong group, or the wrong phase, compared to the first.

If the motor doesn't move, you've found the winding that matches the first one and with the correct phase.

Then mark those two and move on to the other windings to find the phase relationship.

Of course you first use a multimeter to identify the paris of wires for each winding, and twist these together to keep track

Use something like an AA cell to do this, so that inductive kick back isn't going to harm a power supply. The movements are pretty small in a 200-step motor so you need to observe carefully.

If you have a dual or 4 trace oscilloscope you can use it to directly see the phase relationships of each winding, which will be quicker - you simply turn the motor by hand and capture the waveforms.