Controlling 2 different size motors with the same driver

Using Arduino Motors, Mechanics, Power and CNC
1

Hey,
I currently have a project that is working with a nema 34 stepper motor. I would like to use a smaller nema 14 motor to rotate at the exact same time as the larger motor (the smaller motor is intended to be mounted to a camera to time-lapse what the larger motor is doing). Given both motors require different voltages I was wondering if there is a way for the nema 14 motor to receive and use the same signals from the driver intended for the nema 34 motor.

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Is this something that would be possible? I'm sure it would be fine with 2 motors of the same voltage. Or would I have to purchase another driver and hook it up to the arduino/adjust software to get the result I'm after?

2

Hi
I'll assume this is possible as long as none of the motors use polarity reversal for control.
But I'm not entirely sure and would glad to hear what others have to say

3

I would use a second driver for the smaller stepper. An A4988 or a DRV8825. Those are inexpensive drivers. Connect the step pins of both drivers to the same Arduino step pin and the dir pins to the same Arduino dir pins. Then, the motors can be supplied their own supply voltage and will step in synchronization.

4

I wouldn't advise it. When the 12V motor switches, since it doesn't have a reverse-bias diode across it, it will be dumping a big spike into that 12V supply and my guess is that the supply won't be happy about it.

Use two drivers or power them both from the same power supply. Worst case, you can use a current limiting resistor on the smaller motor.

5

The "schematic" in the original post makes no sense. The power supply connects to the driver, not the motor.

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@cedarlakeinstruments, The OP is using stepper motors.

OP, if you do decide to use the A4988 or DRV8825 drivers you must set the coil current limit on the driver before using the stepper. This page explains how >> How to set your stepper driver current: A4988, DRV8825, TMC2208, TMC2209 | Circuitist.com

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No, that is not possible. The driver not simply sends signals to the stepper. The stepper coils are an integral part of the driver system to work properly and control the motor current. This is a one to one relationship. Only if you have two motors that need the same coil current you may connect the coils of the motors in series. Then for the driver its like one motor coil and the same current flows through both coils.

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Hi did u ever figure out a solution to your problem? I'm facing a somewhat similar situation. I have two motors similar to yours and want to use only one arduino and power supply.

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You can use one arduino and one PSU for both motors, but you need 2 drivers ( one for each motor )

1 Like
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Yea I get that. I just don’t want to burn out one of the drivers/motors/ circuits boards. How do I prevent this?

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OP did not understand that stepper motors are driven with current, not voltage.

You can use the same driver for the smaller motor, as long as you (can) set the right motor current on the driver. Maybe the easiest way if you must use that 72volt supply.

How do you know that.
OP didn't post any motor specs, apart from the size of the mounting plates.
leo..

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