That is a great illustration Ian, thanks.

OK, so now I'm gonna climb out on my limb.

Is there any device, or way, to introduce something between the drive and the motor to "create" higher inductance to make the drive happy ... and possibly reduce the temp of the motor ?

Or, knock the output voltage down to an exceptable level maybe ?

I really would like to use these together, mainly needing the indexing drive.
Just trying to use what's on hand.

Thanks

well.... I know there's inductors which can be used to alter a circuits inductance and I know there's potential dividers that drop voltages... but whether thay can be used to do what you need is beyond my pay scale. 'twould be interesting to know though. If you're on the zone I reckon you should ask in "stepper motors and drivers" - maybe Marris will come forth. I reckon he's your man for this. Be sure to keep us informed though - interesting question.

Ian

Might just do that Ian. Havent been there for quite a while.
The larger Parker motors are petty scarce, found only 1 at auction ... in Singapore.
Cool calc. here  -  http://www.diyaudioandvideo.com/Calculator/Inductor/
Interesting to enter various gauges of wire and observe the results.
If I persue this further, I'll post back.
Thanks for your time folks,
Russ

Russ,
I don't know how that drive works ie;  remember in a typical ac motor if one lowers the voltage the amps go up ( that's how you burn up motors
since the resistance to the increased current becomes heat and without thermal protection amps go to infinity if the ability is there to do so).

Typicaly for a stepper a low voltage will limit the max rpm possible since the the abillity to energise the motor winding  is diminished. If voltage is ok but amps are low the motor won't work right, since you can't energize the inductive field enough to hold the torque or step it. At very low amps it may not even turn. The lower the inductance of the motor the faster the current gets to the windings. If one increases the amps it works correctly but then as the fields alternate the losses due to inductance becomes heat. Putting fins on the motor would allow for conducting some of the heat away ( maybe 10 degrees or so unless you have forced air cooling / convection like a fan blowing over the fins).

But forget all of the above since don't know how that drive is sensing current or voltage and adjusting accordingly given some designed inductance.
So not sure what affect putting additional external inductance will have on the drive and for that matter how the phases will react to the external inductance.

I would call Parker and talk to one of their tech support guys. Sometimes if you just tell them upfront what your concerns are and that your trying to save some money for the "company" ( btw, some are responsive to hobbiest if they are not busy!) .

Always interesting to find out dumb ( hey hey ....me  not you folks .....) when you get into the expertise of a different discipline. 

RICH

Thanks Rich !
I did not inquire further regarding the external inductors. Magnet wire is not cheap, not bad at auction though. I did find a Nema 23 stepper that should work OK with this drive but it's a little smaller than I' like.
I will keep watch for a matched Parker motor, or get a more modern indexing drive.
There are several servos and indexing drives here but are for other applications.
Thanks again Gents,
Russ