In today’s instructable, we help you build a simple and elegant prototype for a remote controlled car, with a wooden base, that incorporates 3D printed Polylactic Acid (PLA) for the motor bracing and the adapter which connects the motors to the plastic tires. We will also show you how to motorize your car and give it some motion using circuitry such as the Arduino Uno, Bluetooth receiver, and a motor shield to operate your car with a smartphone and using Android apps such as ArduDroid by TechBitar. Along with the electrical hardware, we will also walk you through on how to program the code to run the motors.
Step 1: Materials/Tools
- 3D Printer
- Soldering Kit (Helping Hands, Soldering Iron, Solder)
- Battery Holder
- Band Saw
- Wire Cutter/Stripper
- Polylactic Acid (PLA)
- Arduino Uno Circuit Board
- 9V Battery
- Wires (Female to Male Jumper Wires ; Male to Male Jumper Wires)
- Bluetooth Receiver (https://www.amazon.com/LeaningTech-HC-05-Module-Pass-Through-Communication/dp/B00INWZRNC)
- Motor shield (Adafruit) (https://www.adafruit.com/product/1438)
- Tires with Rubber Tubing
Step 2: Building the Wooden Base
We started our project by cutting out a 6 in X 10 in piece of plywood using a band saw. We decided to use wood instead of polystyrene foam, because the polystyrene was too fragile and did not fit all the components of the car, such as the Arduino Uno and the DC motors. After cutting the wooden board, we placed the wheels on the back of the base and marked the center of the wooden board using a pencil to indicate the placement of the Arduino Uno board.
Step 3: 3D Printing Wheel Parts and Motor Clamps
We ran into two small problems with the DC Motors that we had to overcome. The first one was that the motor's axle was too small to fit into the hole of the wheel. To fix this problem, we created a cylindrical fitting in OnShape, that created a snug fit for the wheel and the axle, allowing it to spin well.
The second problem we ran into was getting the cylindrical motor to stay on the flat wooden plank. We fixed this problem by creating a clamp-like part in OnShape, which would allow us to screw the DC motors into the wood giving a snug fit for wheels of the car.
Step 4: Video of 3D Printer [Cylindrical Fitting]
A video of the 3D printer printing the cylindrical fitting for the tires.
Step 5: Attaching the Motor Shield
After building the base of the car, we moved our attention to the Arduino Uno board. We decided to buy a motor shield from Adafruit Industries to protect the components of the Arduino. Additionally, using the motor shield allowed us to connect up to four motors, thereby building a faster prototype. We started off by securing the motor shield to the Arduino Uno using the included pins. Next, we secured the pins to the motor shield by clipping the Arduino and the shield, using the helping hands, and then soldering the ends of the shield to the attached pins on the Arduino Uno. Lastly, we began soldering some wires on the motor shield which will connect to the Bluetooth module.
Step 6: Attaching the Other Components to the Motor Shield (Bluetooth Module and Motors)
After soldering the wires and motor shield onto the Arduino Uno board, we began attaching the other components of our remote control car. We first connected the Bluetooth module to the motor shield by connecting the RX, TX, VCC, and Ground on the module to the TX, RX, 5V, and Ground on the motor shield respectively. Later, we proceeded to connect our motors by attaching the red and blue wires of the motors to the blue terminals on the motor shield.
Step 7: Reflection
While doing this project, we enjoyed taking on the challenge of creating the RC Car prototype. At the beginning of this project, it seemed almost impossible and we were second guessing ourselves as to whether we should really build a remote controlled car. We also liked that this prototype integrated both the use of Bluetooth and Arduino. We as high school students had never worked with Arduino or the Bluetooth module, and by the end of this project, we obtained a vast knowledge about how to connect the Bluetooth module to the motor shield and the Arduino Uno to power up DC motors.
If we could change something about this project, we would have changed the connections between the motor shield and the Bluetooth module as we wasted a lot of time trying to wirelessly operate the DC motors using our smartphones and constantly troubleshooting using an LED when the DC motors did not work with the Bluetooth module.
If we could do this project again, we would definitely focus on using other electrical equipments such as the Raspberry Pi, as this allows us to customize more features of the car and work with a variety of operating systems such as Windows 10 and Linux. Finally, we would also try using a Bluetooth receiver/module that would work with both IOS and Android as we could operate the car using different smartphones and also troubleshoot more easily in case of any problems, thereby allowing us more time to build the entire car.