Pololu Robotics & Electronics
Menu
My account Comments or questions? About Pololu Contact Ordering information Distributors

Driving a 3Amps stepper using two DRV8825 in parallel


#1

Hi,

I am desperately looking for a cheap but reliable solution to drive my Nema 23, 270 oz-in, 3A/phase stepper motor for a high torque robotic application using an Arduino. Since each DRV8825 can provide up to 1.5 A with no cooling needed, does it make sense to use two of DRV8825 drivers in parallel to drive one motor? Do I get a smooth pulse with the right timings at the output?
Thank you in advance for your help.

Sadegh


#2

It may work, but I wouldn’t do it that way. If one of the controllers is a fraction ahead of the other, it may detect overcurrent and chop off drive, and then the other will be over-drawn and chop off drive, and then you’ll get oscillation and no joy.

I would look at the higher-power motor drivers. The main problem there is that you typically only get one H-bridge per controller and don’t get any built-in micro-stepping.


#3

Hello.

I strongly advise against paralleling two stepper motor drivers.

In general, H-bridges are hard to parallel. In this case, you would have at least four H-bridges involved. On top of that, the current limiting scheme would need be synchronized (which might not be possible). The step translators would also have to be synchronized. All that considered (plus more issues I probably haven’t!), I am pretty sure it is not feasible.

- Ryan


#4

Thank you very much for your responses. I have already tried 3 parallel H-Bridges but I got very poor performance and the speed range was very limited. I also tried the 3 Axis TB6560 chinese boards on Ebay. Not only it didn’t turn my 3 Amps stepper but also killed my Arduino. This time I will probably go with higher current H-bridges and build up my own driver board from scratch.


#5

Hi sadegh. I´m using in my cnc shield the Z and the A y paralel and work perfect with a single Nema 34 motor