[eon]

I know you can use 10-20x voltage on a stepper motor; but if the motor uses 1.2A and say I'm using 3 motors, does the power supply need to be 1.2A or 3x1.2A - 3.6ish.

[jschmitt]

I know you can use 10-20x voltage on a stepper motor; but if the motor uses 1.2A and say I'm using 3 motors, does the power supply need to be 1.2A or 3x1.2A - 3.6ish.

I have read here on the zone that you only need 2/3rds of the total rated amps of the motors for a power supply. Total motor rated amps times .67 = total PSU amps.

Read the attachment in post #6 here:
http://www.cnczone.com/forums/showthread.php?t=68715

you can of course oversize the power supply without any problems.

[ger21]

but if the motor uses 1.2A and say I'm using 3 motors, does the power supply need to be 1.2A or 3x1.2A - 3.6ish.

Depends on what drive's your using.

[Sparky_NY]

Also, the 10-20x the motor voltage is a old rule of thumb developed back when round stepper motors were the standard. I talked with a engineer at Gecko drives a while back and learned this. There is a simple formula for maximum voltage which multiplies the motor inductance by a constant which is better suited to todays square hybrid stepper motors. The formula is in the instruction sheet for a G201 drive and can be had at Gecko's website.

[Crevice Reamer]

Hi eon. Welcome to the Zone!

Best Power Stepper Voltage formula: 32 times the square root of inductance in mH.

Power supply Amperage formula: Total motor Amps times .67.

UNLESS you are running dual slaved steppers on one router axis. In THAT case, you should size PSU for total Amps.

CR.