1.24v/5.4 stepper motor with arduino?

Hi all,

I am trying to build my very own cnc/laser cutter machine and I got 3 SLO SYN KML061F11 step motor from a friend. These motors run on 1.24Vdc and 5.4(!) amps, now I couldn't find any driver that supports this voltage and current, because I dont plan on spending 100$+ I dont think that using a slo-syn driver as I assume it is very expensive.

Does anyone have any ideas on how can I make my own step motor driver that will support this voltage and current? I tought about using mosfets (such as irf9540N) but how can I provide that exact voltage (as the Vthreshold of the motors vary between 2-4v)?

Thanks for any advice.

Your Design Criteria and your Budget do not seem to be compatible, but the day is young. You may get lucky.

now I couldn't find any driver that supports this voltage and current

Most industrial stepper drivers will handle 5A - did you look?

The voltage is not relevant, steppers like this are current driven.

So is it possible to use 12v (with enough current, ofcourse..) with this motor although it says 1.24vdc on it? I was thinking about using parallel sn754410ne with the old version of the motor shield (about 6 of those..) in order to handle the current. will that do?

Another question, is 5.4Amps the total amount of current needed or do I need 2X5.4amps (as I have 4 wires I guess there could be 2 currents in parallel)?

srusha: So is it possible to use 12v (with enough current, ofcourse..) with this motor although it says 1.24vdc on it? I was thinking about using parallel sn754410ne with the old version of the motor shield (about 6 of those..) in order to handle the current. will that do?

I repeat "the voltage is not relevant, steppers like this are current driven"

You'd probably use 24, 36, 48, or 72V in practice to get high performance. Forget the voltage rating, this is a 5A motor with 1.24mH of winding inductance, those are the critical parameters and they mean this motor can go really fast (3000rpm or more) with a high enough supply voltage. The inductance and motor back-EMF are what determines the voltages involved, the winding resistance is utterly swamped by these other sources of voltage.

You use a chopper driver with this motor only, it is current driven.

Another question, is 5.4Amps the total amount of current needed or do I need 2X5.4amps (as I have 4 wires I guess there could be 2 currents in parallel)?

That's the amplitude of the 2-phase AC current waveform, you don't need to worry about that, that's what the chopper driver takes care of. You need to worry about the current into the chopper driver which is a complex function of the supply voltage, motor speed and load! It could be less than 5A even.

Great, thanks for the very detailed answer, that really helped!

Hi Mark, A follow up question:

I was thinking about buying "MKS TB6600" http://reprap.org/wiki/MKS_TB6600 as it is chip is allows up to 4.5 working current.

Do you think that 4.5 will give me "good enough" control over the motor? The working current of the motor is 5.4amps. I am aware that it wont be optimal and could perform better with 5.4A, but will it work?