RoadRunner 5 Assembly Guide

1. Preparing the Servos

Remove the screw and geared hub from the servo. Set aside the screw, it will be used later to attach the wheels.

The servos will be attached to the chassis like this. Make sure to route the wire through the large hole at the front of the chassis.

Use the four 12mm M3 black screws to attach each servo to the servo mounts. Use the M3 nuts to secure the screws and servos. Make sure to attach the servos in a way that the gear hub is towards the front of the frame.

The wires should come up through the center hole in the top of the frame.

The glass marble can be installed at this time. Simply press it into the marble mount.

2. Installing the Arduino

The standoffs for the Arduino snap into the holes on top of the chassis

Pro tip: A screwdriver can help press the standoff into their holes

Only three screws will fit in the Arduino screw holes

3. The Ultrasonic Sensor

Attach a 4-pin jumper wire to the ultrasonic sensor. Take note of the wire colors attached to each pin. They will be needed later.

Press the sensor housing into its slot at the front of the frame. The servo wires will run behind the ultrasonic sensor. They can also be routed below the Arduino to their respective sides.

The wires will be plugged into the following pins:

  • VCC --> 5V
  • TRIG --> 8
  • ECHO --> 7
  • GND --> GND

More details about how to wire the ultrasonic sensor will be found later in the instructions.

4. Supports and Electrical Components

The front and rear support pieces will snap into the slots at the front and rear of the chassis.

The prototyping breadboard can be installed on the back of the RoadRunner. Remove the sticker backing and adhere the board to the frame. This pieces is where most of the wiring will be done later. The breadboard will handle power distribution and signal routing.

Install the rocker switch by lining it up with the rectangular hole at the rear of the chassis and press it straight down until it snaps in.

5. Soldering the Switch and Power Plug

These are the recommended tools for completing this section:

  • Soldering station
  • Wire strippers/cutters
  • Solder
  • Small pliers (not pictured)
  • Heat gun (not pictured)

Cut the negative (black) wire on DC power connector as shown. The switch will be spliced into this cut. Strip and tin the ends of these wires.

Tin the terminals on the switch. Place a small section of heat shrink tubing onto each negative wire and solder the black wires to each end of the switch.

The switch should look like this once the wires are soldered on.

Slide the heat shrink over the exposed terminals.

Use the heat gun to shrink the heat shrink tubing on the terminals.

Use a small set of pliers to crimp Tamiya connectors to the positive and negative wires.

Solder them as well as crimp them to make sure they stay connected.

Press the connectors into the white plastic Tamiya connector.

The red wire goes into the square side.

The black wire goes into the rounded side.

Attach the battery using the black pieces of Velcro

Place the fuzzy side on the battery and place the hook side on the bottom of the chassis.

Connect the battery to the Tamiya connector. It should connect red to red and black to black. Don't connect them if the colors don't match.

Use a small section of white Velcro to create a mounting point for the connectors on the bottom of the servos.

6. Installing the Wheels, Bluetooth, and Top Platform

Attach the wheels to each servo hub and secure them with the screws saved from the first step.

Connect the top platform to the the front pillars.

Stick some stiff white Velcro onto the Bluetooth mounting area and the fuzzy Velcro onto the back of the Bluetooth module.


Mount the Bluetooth module onto the spot shown below.

7. Wiring the Electrical Components

The next step for the assembly of the RoadRunner 5 is making sure all the sensors, lights, and servos are powered on and connected to the Arduino correctly. This section includes a wiring diagram created in the program Fritzing. Use this diagram as a guide to your wiring. Below it is an explanation on how the mini breadboard works.

If you examine the mini breadboard closely, you will see that there are rows labeled with numbers and columns labeled with letters. Components plugged into the same row will be connected.

In the diagram above, the red wires are all plugged into the same row (note: the breadboard is sideways). This essentially means they are all plugged into the Arduino's 5V pin since the 5V pin is plugged into the row.

The mini breadboard on the RoadRunner 5 is being used as a power distribution board. It can also be used for other components as well, such as a HC-06 bluetooth module (shown below). The module can be plugged directly into the breadboard so that the four pins are all in the same column, and then wires routed to the appropriate pins on the Arduino.

For a cleaner more compact look, trim the LED pins shorter. Make sure to note which pin is positive and which is negative. The longer pin is the positive pin.

Trim both pins close to the small ridge. Leave the positive pin slightly longer so that it is easy to tell apart from the negative pin when installing the LED.

Install the LED onto the Arduino by plugging the longer positive end into pin 13, and plugging the shorter negative pin into the GND pin on the Arduino. There is an LED built in to the Arduino already that is mapped to pin 13, but this external LED will be easier to see.

8. RoadRunner 5 Code

When everything is wired up, the RoadRunner 5 code can be uploaded to the Arduino to verify everything works properly. The code can be accessed by clicking the button below: