Why do I keeping destroying motor shields?!

Other Hardware Motors, Mechanics, Power and CNC
1

Hello,

As the title says I keep breaking motor shields when I try and drive my 3 motors. I cannot for the life of me work out what I'm doing wrong.

Here's a photo of my setup:

IMG20240216220138
IMG202402162201381920×3413 444 KB

These are links to the kit I'm using:
Motor shield
Pololu-37D 30:1 Geared motor
Pololu Spec Sheet
I'm also using a 11.1v 55c LiPo battery.

I've been running a very basic script just to try and get the motors running as a minimum and have had them running in the past.

#include <AFMotor.h>
AF_DCMotor motor1(1);
AF_DCMotor motor2(2);
AF_DCMotor motor3(3);

void setup() {
  Serial.begin(9600);
}

void loop() {
  motor1.run(FORWARD);
  motor1.setSpeed(255);
  motor2.run(FORWARD);
  motor2.setSpeed(255);
  motor3.run(FORWARD);
  motor3.setSpeed(255);
}

Thanks for your help!

2

The ancient, extremely inefficient L293D driver on that motor shield can handle only very small motors, with 0.6A maximum steady state current draw per channel.

The Pololu motors each briefly draw the start/stall current of 5.5A, 10X the rating of the L293D driver, every time they start moving.

Pololu sells modern, highly efficient MOSFET motor drivers. Select one that can easily handle the 5.5 A startup current.

2 Likes
3

Thanks for clearing that up!

Are the more modern motor drivers compatible with Arduino? What specs should I be looking at to choose an appropriate driver?

4

As already suggested, pick a Pololu motor driver that can easily handle the 5.5A startup current.

Spend some time on the Pololu site. Loads of valuable information is posted, including wiring diagrams, example code and installation instructions.

1 Like
5

Thanks for your help. I'm on a fairly tight budget and have to order from a list of approved suppliers. Would this be appropriate?

Motoron M3S256

6

Polulu page for that controller states: The M3S256 supports motor supply voltages from 4.5 V to 48 V and can deliver continuous output currents up to 2 A per motor .

IMO, give yourself some headroom and select a controller with double digit current output.

YMMV

1 Like
7

Thank you!

8

The Motoron M3S256, with peak instantaneous current 6.4A per channel, is barely adequate for the linked motor. If that is all you can afford, it will work, but as mentioned above, it is safer and more reliable to be generous in sizing motor drivers and motor power supplies.

2 Likes
9

Thanks. I'm using Motoron M2H boards now and all it seems to be working well so far!

10

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