How to Select Stepper Motors

Info from Duet -

"Preferably, the driver supply voltage should be at least the sum of these two back emfs, plus a few more volts. If you have two motors in series then the required voltage is doubled." and more at

https://duet3d.dozuki.com/Wiki/Choosing_and_connecting_stepper_motors

• It has notes about wiring steppers in series.
• "Avoid motors with rated voltage (or product of rated current and phase resistance) > 4V or inductance > 4mH."
• Shows how to identify stepper motor phases by shorting phases via wire