Power supply for 10 nema 17 stepper motors with DRV8825 Stepper Drivers

Using Arduino General Electronics
1

Hi everyone

I have a Kinetic artpiece i'm currently making controlling 10 stepper motors (NEMA 17 + DRV8825 Driver) simultaneously with 3 HC-SR04 Ultrasonic Sensors on a Arduino Mega 2560.

I need to know what power supply I would need to power the whole system?
And can I use the same supply to test on 1 motor or do I need to reduce the amps with a resistor?

I saw that I also need to set the Motor Current Limit on the DRV8825 Driver.
I found that you need to divide the Imax by two ,That would be 0,9V. Is that right?
Someone recommended me to -10% off the vallues to be safe ,that would make it 0,81V

This is the datasheet of the stepper motors.
I hope I gave enough information...
I’d really appreciate if someone could clarify this
Thanks

2

1.8 Amps is pretty high for a DRV8825. They will need heat sinks and fan cooling if you want them to run very long without shutting down. That is for quality drivers. Cheap Chinese knock offs may not work as well.

I would say to get at least a 20 Amp power supply for the steppers. 30A for cheap Chinese.

You do not need to reduce the current from the power supply to run one motor. The driver controls the current (if set properly) and will pull the current that it needs, no more.

The Pololu DRV8825 page has good instructions on setting the coil current limit.

Someone recommended me to -10% off the vallues to be safe ,that would make it 0,81V

You can set the soil current lower that the maximum for the motor. That will add life to all the components.

What are the motors driving? You probably will need to use some microstepping to avoid resonance problems.

3

Thank you for answering that quick!

It's hard to explain what the motors are driving...
They are driving 10 long triangle shaped beams
So there are 3 sides on each beam ,the motors need to rotate the beams on 3 different locations
The weight of each beam is still undefined because I still need to figure out what material to choose for the beams ,I could simply 3d print the beams out of PLA to reduce weight..

And what voltage would the power supply need?

4

You need at least 9V for the drivers (that is the minimum that they will work with). Then up to the maximum that the drivers can handle (45V for the DRV8825). So in between those extremes. For the best performance (speed and torque) use higher voltage. Lower the voltage if you do not need the max. (parts that are not stressed as much so will last longer). I run my 3D printer and my 2D plotter at 12V and they work fine. I have a mini CNC engraver that I run at 12V, too, but may go to 24 V on it for better torque and cutting speed.

The voltage is irrelevant to the drivers. The drivers will compensate for the voltage, they control the current no matter the voltage. Just follow the instructions to set the coil current limit. And check and re-adjust, if necessary, if you change supply voltage.

5

This doesn’t define the current nor voltage of the motor.
The only thing it does define is the physical size of the motor’s casing.

You need to know the current requirement of your motors to allow you to set that from the drivers control.

For a given current rating the greater the voltage the quicker you driver can step the motor without stalling.

6

You would still need bearings at the far end to keep them from flopping around as they are rotated.
Paul

7

If you are mounting the triangles directly to the motors, be sure the number of steps you use is evenly divisible by 3.
Paul

8

This topic was automatically closed 120 days after the last reply. New replies are no longer allowed.