How to select power supply???

Greetings All,

I was recently able to bet some larger motors for the mill conversion,
but am somewhat at a loss on how to correctly size a power supply for them.

Do you choose the power supply first, or the driver boards?
Do you *add* all the amperages for *each* motor?
(for me adding three motors?)
And how can I tell at what voltage these are safe to run at?
12V or 48V????? Or somewhere in between?

I have *some* schematics available to me,
but haven't been able to make heads or tails of them.
Let me know what I should be looking for on them, maybe?

Any info is appreciated~!

Sigma Model #20-4247TD200-F1.3
8 Wire Connection

Field Winding - 1.3 ohms
Amps Per Winding
3.5a - UNIPOLAR
5.0a - BIPOLAR

Torque
540 oz. In. @ 50 Steps per Second
635 oz. In. Holding Torque

Steps Per Revolution
200 Steps per Revolution - Full Step Mode
400 Steps per Revolution - Half Step Mode

Weyland