[will_eng]

Is it possible to change a 6 wire stepper to an 8? Is the center lead tapped into the coil or are there really 2 coils in series? Schematics look like series. I have a 4 terminal output from my controller(+A,-A,+B,-B). So my manual said to discard center connection of motor and treat two sets of coils in series. It says if I do this I will have to half the current though. I have 125oz/in 2.0A per phase motors that I’m running at 1A this way and they have virtually no torque. Is there anything I can do to over-clock them for the time being. I plan on getting bigger motors in the future.

[irving2008]

Its very unlikely you can do that. The centre tap is usually buried in the winding.

There's no reason to reduce the current, however you might find the motors work better if you use one end and the centre tap instead of the two ends and run at rated current.

[will_eng]

I did run the motors at rated 2.0A which made a considerable dereference. Although using the center tap and one of the others resulted in even less torque. I can also adjust percent fast decay. I know this probably does not have any relation to torque but I have it set to the manuals recommended 2.5VDC. Can anyone tell me more about what this effect has on motor turning?

[BCwanderer]

Is it possible to change a 6 wire stepper to an 8? Is the center lead tapped into the coil or are there really 2 coils in series?

The centre wire is common to both coils.
If you open the back of the motor, you will see where the common wire can be separated and brought out to make an 8 wire motor.
See thread http://www.cnczone.com/forums/showthread.php?t=13793

Schematics look like series. I have a 4 terminal output from my controller(+A,-A,+B,-B). So my manual said to discard center connection of motor and treat two sets of coils in series. It says if I do this I will have to half the current though.

I have 125oz/in 2.0A per phase motors that I’m running at 1A this way and they have virtually no torque. Is there anything I can do to over-clock them for the time being. I plan on getting bigger motors in the future.

The centre wire is common to both coils.

The two coils are bucking in series in a 6 wire motor.
In a six wire motor, only one coil per pole is activated at any one time.
You have to reverse one coil and either reconnect them in parrallel for increased current or reconnect them in series for higher voltage.

An alternate fix is to use only one coil per phase and connect the coil as a bipolar motor. The second half of the pair is abandoned.
If you open the back of the motor, you will see where the common wire can be separated and brought out to make an 8 wire motor.
See thread http://www.cnczone.com/forums/showthread.php?t=13793
I hope this makes sense for you.

[will_eng]

This is interesting. How does each setup using higher current or higher voltage effect motor torque or speed.