Newbie- Current and Voltage Calculations -Check Please?

[Zathras]

Hey guys,

I need to check my calculations with some experienced people out there.
Don't wanna kill my nice new Keling!

I have the 8-wire 640oz-in NEMA34 (http://www.kelinginc.net/KL34H280-45-8B.pdf) rated at 6.3A 2.3V in Bipolar Parallel for my Z axis. Resistance is quoted as 0.36Ohm.
Chose the Gecko 201 driver for this beast and I purchased a 70V 6A unreg PSU so this should be fine....... I think!

I can't wire the motor in parallel (Half winding) 'cos the 25x2.3=57.5V limit (suggested by Gecko) is too low for the PSU.
So I'll have to go for serial wiring.
That is; Two windings in series gives 1.42Ohm and so 3.2A @4.5V Right?
So; 25x4.5V=112.5V max PSU voltage. No problem so far.
Meaning I will need a 6.4A PSU to power the motor (both poles) right?

So I'm slightly under max spec but that should be fine.

Appreciate any comments.

[ger21]

The G201 will only draw 2/3 of the motors rated current, just a little over 2 amps in your case when wired in series. And about 4.2amps in parallel. You don't add the phases together. If your looking for high rpm's, you'd probably get better performance with a 48V power supply and parallel wiring.

[Zathras]

Ah....... so let me ask; is the 2/3 factor due to the chopper driver of the Gecko?

And the fact that the phases don't add is because both poles are never energised simultaneously at full current?
Yeah that would make sense!

So I'm no where near the capacity of the PSU and I thought that the higher voltages would give better performance.
I did think parallel winding arrangement made more sense for performance but it's too late now.

Thanks for your help Ger21!