Arduino Controlled 3-Axis Pen Plotter

The purpose of this project was to make a 3-axis pen plotter as cheaply as I possibly could.  Assuming you already have an Arduino it ended up costing me $30 to build.  Please understand that the stepper motors that are inside CD-ROMS are not strong.  If the pen comes down too far it will stop the motors from moving.  This will not harm the motors but I thought it would be worth mentioning.  But if you are looking for a cheap way to experiment with 3-axis's this might be for you. 

The program reads binary 0's & 1s stored in a word array in row/column fashion & then controls the motors accordingly.  You can change what it prints by changing the data in the "image" array.  It's pretty basic & shouldn't be too hard to understand or change to fit your wants better.

I included the schematic I followed for wiring the H-Bridge Motor Drivers (SN754410NE).  I apologize for not having a complete schematic I have not found an easy way to make them.  I used an LM317 5V regulator for each H-bridge, but honestly since I used a computer power supply to give me 5V you shouldn't even need the LM317's.  You could just take the 5v from the power supply & wire it to each H-Bridge.  In my case I built the control board before choosing a power supply.


Part List                                                              Quantity     Cost        Total
H-Bridge Motor Driver 1A (SN754410NE)                3              $2.35       $29.25
Voltage Regulator (LM317)                                      3            ~$1.95
10uF/25V Capacitor                                                  3             ~$0.45
Used CD-ROM                                                           3             ~$5.00

Arduino Duemilanove/UNO   (This indestructible assumes that you already have one) ;)    

If you don't already have an Arduino the total cost will be closer to $60.00.
                                                           

In case you don't want to download the zip file, the code is below:

//Beginning

#include <Stepper.h>

// change this to the number of steps on your motor
#define STEPS 200

// create an instance of the stepper class, specifying
// the number of steps of the motor and the pins it's
// attached to
Stepper stepperX(STEPS, 6, 7, 8, 9);     //x (top) platform
Stepper stepperY(STEPS, 2, 3, 4, 5);     //y (bottom) platform
Stepper stepperZ(STEPS, 10, 11, 12, 13); //z pen

int x_inc = 0;
int y_inc = 0;
int z_pos = 0;

word image[16] = {
  0b0000001110000000,
  0b0010011111000100,
  0b0010001110000100,
  0b0010000100000100,
  0b0011111111111100,
  0b0000011111000000,
  0b0000011111000000,
  0b0000001110000000,
  0b0000011111000000,
  0b0000011111000000,
  0b0000110001100000,
  0b0001100000110000,
  0b0001100000110000,
  0b0011100000111000,
  0b0011100000111000,
  0b1111111111111111
};


void setup()
{
  // set the speed of the motors to 60 RPMs
  stepperX.setSpeed(60); //bottom (60rpm)
  stepperY.setSpeed(60); //top (60rpm)
  stepperZ.setSpeed(60); //Pen (60rpm);
  delay(2000);
}

void loop()
{
  
    for(int row = 0; row < 16; row++) {

      penUp();
    
      stepperX.step(-x_inc);
      x_inc = 0;

      for(int column = 0; column < 16; column++){
        boolean pixel = bitRead(image[row],column);
        if(pixel == 1){

          penDown();
        
          //move X-Axis forward 5 steps for each bit in the array
          stepperX.step(10);
          x_inc = x_inc + 10;
          delay(15);
        }
        else{

          penUp();
        
          //move X-Axis forward 5 steps for each bit in the array
          stepperX.step(10);
          x_inc = x_inc + 10;
          delay(15);

        }
      }
    
      penUp();

      //Position Y-Axis for next row
      stepperY.step(10);
      y_inc = y_inc + 10;
      delay(15);
    }

  penUp();

  //Return X/Y-Axis back to home position
  stepperX.step(-x_inc);
  stepperY.step(-y_inc);

  //Endless Loop
  while(1){
  }

}


void penDown()
{
  //if the pen is raised
  if (z_pos == 0){
    //move the pen to the paper
    stepperZ.step(83);
    delay(15);
    z_pos = 83;
  }
}

void penUp()
{
  //if the pen against the paper
  if(z_pos == 83){
    //move pen away from paper
    stepperZ.step(-83);
    delay(15);
    z_pos = 0;
  }
}

//END

Source:http://www.instructables.com/id/Cheap-Arduino-Controlled-3-Axis-Pen-Plotter/