Sire stepper coils in series or parallel ???

[TarHeelTom]

On the downhill slope now on rehabbing a Bridgeport with a PC, EMC2, and Gecko 203V drives, 56 Volt power supply.

Have the drives moving now with the coils wired in series.

Then a friend tells me they should be wired in parallel?

Anyone got an informed opinion?

Thanks

Tom

[Crevice Reamer]

Parallel is usually best and will provide the maximum power and speed. The motors must be able to accept your PSU Voltage and be <=7A in parallel though.

What motors are you using? What is their inductance in series and in parallel?

CR.

[TarHeelTom]

I'm using the stock steppers which Bridgeport installed on the machine originally. Can't find my Bridgeport maintenance manual the last several weeks (spring cleaning) so can't look it up. I've not stumbled across a datatag on the stepper motors yet (haven't removed them, hope not to have to).

But the blueprints in the manual show the original monster DC power supply in the machine to be a 56 volt dc line. I ordered a 56 volt power supply from Keling based on the blueprints.

Don't really understand how Bridgeport did things, but they have six wires from the steppers. There were two coils wired in series, with a wire to each end and a wire to the center tap.

Here is a picture of the X stepper, and the others appear to be identical.
http://tomwade.me/tw/machinist/nm/t4.php


Thanks

Tom

[Crevice Reamer]

Originally Posted by TarHeelTom I'm using the stock steppers which Bridgeport installed on the machine originally. Can't find my Bridgeport maintenance manual the last several weeks (spring cleaning) so can't look it up. I've not stumbled across a datatag on the stepper motors yet (haven't removed them, hope not to have to). But the blueprints in the manual show the original monster DC power supply in the machine to be a 56 volt dc line. I ordered a 56 volt power supply from Keling based on the blueprints. Don't really understand how Bridgeport did things, but they have six wires from the steppers. There were two coils wired in series, with a wire to each end and a wire to the center tap. Here is a picture of the X stepper, and the others appear to be identical. http://tomwade.me/tw/machinist/nm/t4.php Thanks Tom

You CANNOT wire six wire motors bipolar parallel. The best you could do is wire them Half-coil--which is nearly as good as parallel--IF the motors will accept your Volts & Amps.

The original motors were apparently wired as unipolar.

There is info on different wiring methods here:
http://crevicereamer.com/Page_2.html

CR.

[TarHeelTom]

Originally Posted by Crevice Reamer You CANNOT wire six wire motors bipolar parallel. CR.

Why not?

I'm serious. There are four separate coils in each motor, and eight terminals in the junction box on the end of the motor. Bp used a jumper to connect the ends of two of the coils together to make a center tap. If I remove that jumper, I've got four separate coils again.


http://tomwade.me/tw/machinist/nm/t4.php


Tom

[Crevice Reamer]

Originally Posted by TarHeelTom Why not? I'm serious. There are four separate coils in each motor, and eight terminals in the junction box on the end of the motor. Bp used a jumper to connect the ends of two of the coils together to make a center tap. If I remove that jumper, I've got four separate coils again. http://tomwade.me/tw/machinist/nm/t4.php Tom

Well, in THAT case, you effectively have an 8 wire motor that can be wired as ANY of the wiring methods available--and CERTAINLY can be wired in parallel.

CR.

[CNCfun&games]

Crevice Reamer:

I recently Upgraded my Boss 4 . I used a 68V Pwr Supply with G203V's
using the stock Sigma Motors. They MUST be wired “ series.”


Sigma Motor # 21-4266D-200-F022
910 oz/in Bipolar 12.7 A .21ohm
Series 21, Hi speed / Hi torque Motor - 8 wire

TarHeelTom:
The Motor shown in the photo is the stock Superior Slo Syn Motor.
They are also Hi- current
Search the Bridgeport Forum and you will find that “zoners” have
wired the motors every way possible.

Good luck..... W.Smith, Mission Viejo, CA