Six position stir plate

Most of my experiments require triplicate test and control reactors, so I typically have six reactors running at once. I built this six position stir plate because I quickly ran out of bench space and stir plates! It’s built from aluminum t-framing for the structure and a stepper motor controlled by an Arduino board communicating through a Big Easy Driver. Below is a bunch of photos, design details, and code to show how I made this stir plate. I also offer to build these stir plates for $500 each.


  • Fully customize-able
  • 6 positions for stirring, all at the same speedĀ via pulleys
  • 0-1000 rpm
  • No motor electronics beneath reactors


The Code

The code loaded on the Arduino drives a Big Easy Driver, and it’s really simple! With the current gearing on the stepper motor and the stir rods, this runs my stepper motor at 100 rpms.

int ledPin = 13;                 // LED connected to digital pin 13

void setup() {
  pinMode(2, OUTPUT);
  pinMode(3, OUTPUT);
  digitalWrite(2, LOW);
  digitalWrite(3, LOW);
  pinMode(ledPin, OUTPUT);      // sets the digital pin as output

void loop() {
  digitalWrite(3, HIGH);
  digitalWrite(ledPin, HIGH);   // sets the LED on
  digitalWrite(3, LOW);
  digitalWrite(ledPin, LOW);    // sets the LED off