Arduino Drawbot 2.0

This is a tutorial for creating an Arduino Drawbot. This design is based off of a design by biomech75 and if you would like to see what he used for his project you can check it out at this link below.

Arduino Drawbot by biomech75

https://www.instructables.com/id/Arduino-Drawbot/

List of Materials

- 1 Block of wood, preferred size : 2 inches x 7 inches, thickness anything less than 1 inch

- 2 Continuous Rotation Servos (https://www.adafruit.com/products/154)

- 1 Bedboard and Arduino Uno

- 1 pen or marker (any color)

- 2 wheels (I personally used 2 spray can caps and covered them in rubber bands)

- Rubber bands

- 9v Alkaline Battery

- 9v Battery Clip for Arduino (https://www.adafruit.com/product/80)

- Many Wires for connecting servos, power, ground, etc.

Step 1: Getting Your Wooden Board

First you will need to cut a piece of would in the shape pictured above. The length of the board is entirely up to you as well as the width and thickness. Above are two examples of boards I cut out which both worked fine. The only necessities when cutting the board are to make a hole near the top for a marker to fit and for the board to be able to support an Arduino and well as a breadboard.

Dimensions For My Board:

- 2 inch width

- 8 inches from base to tip

- less than 1 inch in thickness

Step 2: Making the Wheels

To begin making the wheels you will need something such as paint can caps as shown and the 2 continuous servos. I did not use paint can caps but instead hair spray caps which are essentially the same thing. The cap size are personal preference as they'll work fine regardless. I attached the caps through the back by screwing in the portion of the servos which have holes that allow small screws to pass.

Step 3: Attaching the Wheels to the Board

After the wheels have been screwed onto the servos you will need to add something to wrap the wheels in order to have them move smoothly. What I used were large rubber bands and continuously wrapped the wheels in as many layers of rubber bands as possible before the caps began bending.

Now to attach the wheels and servos to the board you can just wrap the servos with several small rubber bands until they hold steady to the board without much space to shift. The images above show what the back portion of the bot should look like after this.

Step 4: Wiring the Servos and Placing Breadboard

The wiring for the servos is simple and is the same as any example of wiring a single servo. The two images above show the connections that should be made from the servos to the breadboard. The two servos should be connected to Pins 9 and 10.

After the wiring is done the breadboard can be directly placed onto the body and held down easily with a couple of rubber bands. The last image shows what and where the placing of the breadboard should look like and be .

Step 5: Placing the Arduino and Battery

This is where the 9v battery and clip will be needed. Since the power from a usb port is not sufficient to rotate both servos, you will need the 9v battery for both wheels to turn at the same time.

The arduino can be attached easily and similar to the breadboard. The arduino can be held by rubber bands as shown in the image. After the arduino is placed then the battery can be placed in the back part of the bot where it can just lay.

Step 6: Finalizing the Drawbot

The last step to the Drawbot is the coding.

Here is a sample of code which I used to make the Drawbot move in all different types of directions. In order to make the bot draw different things or move specific directions, you can just modify this code:

#include
Servo servoLeft; // Define left servo

Servo servoRight; // Define right servo

void setup()

{

servoLeft.attach(10); // Set left servo to digital pin 10

servoRight.attach(9); // Set right servo to digital pin 9

}

void loop()

{

forward();

delay(2000);

reverse();

delay(2000);

turnRight();

delay(2000);

turnLeft();

delay(2000);

stopRobot();

delay(2000);

}

void forward()

{

servoLeft.write(0);

servoRight.write(180);

}

void reverse()

{

servoLeft.write(180);

servoRight.write(0);

}

void turnRight()

{

servoLeft.write(180);

servoRight.write(180);

}

void turnLeft()

{

servoLeft.write(0);

servoRight.write(0);

}

void stopRobot()

{

servoLeft.write(90);

servoRight.write(90);

}

Step 7: Finished Product!

Now just add any type of marker or pencil in the hole you made and you have yourself your very own Drawbot!