TrackBuddy XT: the All-Terrain Robotic Friend

Meet TrackBuddy+: Your All-Terrain Robotic Companion

TrackBuddy+ is not just a remote-controlled tank—it’s a loyal robotic sidekick built to assist, explore, and interact! Powered by an Arduino Uno and driven by a 4x4 motor system, this bot features a functional robotic arm and claw that can pick up small objects with ease. Designed for rugged mobility and precise control via a 10-channel RC transmitter, TrackBuddy+ is the perfect blend of engineering and personality. Whether it's helping you grab something across the room or just rolling around as your mobile buddy, this project embodies what it means to have a true robotic friend.

1. Arduino Uno
2. HW-130 L293D Motor Driver Shield
3. Hot RC 10-Channel PWM Receiver
4. Hot RC Transmitter
5. 4× BO Motors (DC geared motors)
6. 2× SG90 or MG90S Servo Motors
7. Claw or Gripper attachment
8. 2× 18650 Battery Holders (2 cells each)
9. 4× 18650 Li-ion Batteries
10. Power switch
11. Male-to-Male Jumper Wires
12. Stackable Header Pins
13. Tank tracks or wheels
14. Chassis base plate
15. Double-sided tape or zip ties
16. Screwdriver set
17. Soldering kit (optional)
18. Multimeter

1. Attach the 4 BO motors to the chassis base plate using screws or motor mounts.
2. Install the tank tracks or wheels securely onto the motor shafts.
3. Ensure the motors are aligned properly for smooth 4WD movement.
4. Mount the 18650 battery holders on the chassis with double-sided tape or screws.
5. Leave space at the top for the Arduino + motor driver shield and the receiver module.

Note: Ignore the breadboard and ESP32, the image is just to show how the tracks should look after installation.

1. Mount the L293D motor driver shield onto the Arduino Uno.
2. Connect the four BO motors to the motor terminals on the shield (M1–M4).
3. Insert stackable header pins if your shield blocks access to the digital pins (you’ll need D2–D6 or similar for the receiver).
4. Connect the RC receiver’s channel outputs to available Arduino digital pins using jumper wires:
5. Ch1 → D1 (Throttle – Forward/Backward)
6. Ch2 → D2(Steering – Left/Right)
7. Ch3/Ch4 → Servo 1/Servo 2 (Optional extra functions)
8. Power the receiver from the 5V and GND servo headers on the motor driver shield.
9. Connect servo motors to unused receiver channels (e.g., Ch3 and Ch4) for arm and claw control.
10. Wire up the battery pack to the motor driver’s power input (typically via the green screw terminal block). Make sure the polarity is correct!
11. Refer to the circuit diagram for all connections.

1. Open the Arduino IDE on your computer.
2. Connect your Arduino Uno to the computer using a USB cable.
3. Select the correct board and port:
4. Go to Tools > Board > Arduino Uno.
5. Go to Tools > Port and select the port that your Arduino is connected to.
6. Copy and paste the code provided in Step 2 into the Arduino IDE.
7. Click the Upload button (right arrow) in the Arduino IDE.
8. Wait for the code to upload. The IDE will display "Done uploading" once it's complete.

1. Power on the tank:
2. Ensure your 18650 battery pack is properly connected to the motor driver shield.
3. Turn on the Hot RC transmitter.
4. Test basic movement:
5. Move the throttle control (typically forward/backward on your transmitter). The tank should move forward and backward based on the PWM signal from the receiver.
6. Test the steering control (left/right on your transmitter). The tank should turn left and right based on the PWM signal.
7. Check the servos:
8. The servos connected to channels 3 and 4 on your receiver should control the arm and claw. Move the respective controls on your transmitter and verify that the arm goes up/down and the claw opens/closes.
9. Check alignment:
10. If the tank does not move as expected (e.g., moves in the opposite direction or doesn’t turn), double-check the motor wiring and ensure the motors are connected correctly to the L293D shield.
11. If the servos don’t respond correctly, check the connections to the receiver and ensure that the PWM signals are properly mapped in the code.
12. Fine-tune motor and servo control:
13. If necessary, adjust the mapping in your code to ensure smooth and accurate movement. You can tweak the map() function values for motor speed or steering if the movement is too fast, too slow, or not responsive enough.

What to check for:

1. The tank should respond to the transmitter’s throttle and steering inputs.
2. The servos should move smoothly based on the control from the transmitter.
3. Ensure no wires are loose or incorrectly connected, especially on the L293D motor driver and the receiver.

💡 Tips:

1. If the motors are not responding or the tank seems unresponsive, ensure the motor shield is seated properly on the Arduino and that power is reaching both the motors and the receiver.

1. Build the Base & Cover
2. Construct a cuboid enclosure to sit on top of the chassis. This acts as both:
3. A housing for the electronics (Arduino, motor shield, wiring).
4. A mounting base for the robotic arm.
5. One side of the cuboid should be cut at an angle—this slant allows for a sliding or liftable cover, kinda like the back of a Cyber truck.
6. Wire Management
7. Route the wires from the servo and RC receiver neatly through the base.
8. Ensure that the wiring does not interfere with the tank’s movement or get pinched by the cover.
9. Test Fit the Cover
10. Place the slanted side or sliding cover back into position.
11. Confirm that the cover fits well and protects the internal electronics while allowing enough space for cooling and maintenance access.

Now that the base and enclosure are ready, it's time to construct and install the arm. This arm gives the tank its functional personality—allowing it to grip, lift, and interact with objects.

1. Assemble the Arm Mechanism:

1. I used lightweight material (MDF, acrylic, or popsicle sticks work well) to create the segments of the arm.
2. The arm has two parts:
3. A vertical segment mounted directly on the up/down servo.
4. A claw attached to the end of the vertical arm, controlled by a second servo.

2. Mount the Arm Servo:

1. The up/down servo should already be installed on the top platform in a way that it tilts the arm up and down.
2. Ensure it can rotate freely up and down without hitting the chassis or cover.

3. Build & Attach the Claw:

1. I used a small servo for the claw, mounted at the end of the vertical segment.
2. The claw itself can be a 2-finger design made from cardboard, more details on the arm in the next step.
3. Plug the claw servo into a free receiver channel (e.g., Ch4).

4. Connect & Test the Servos:

1. Power the servos using the motor shield’s 5V headers.
2. Make sure the servo wires are securely connected and the channels match the transmitter controls.
3. Test both movements:
4. Channel 3 – Arm up/down
5. Channel 4 – Open/close claw

5. Reinforce & Fine-Tune:

1. Check for any wobbly joints and reinforce them with hot glue, screws, or brackets.
2. Make sure the servo doesn’t strain too much—keep the arm light and balanced.
3. Adjust the claw’s range and grip to handle small objects effectively.

Now let’s make the claw mechanism that grips objects using a flexible, spring-like U-shaped design. This setup uses a single servo to pull a wire that tightens the claw tips inward.

1. Form the U-Shaped Claw:

1. Cut a piece of sturdy but slightly flexible material (e.g., acrylic, aluminum strip, or spring steel wire) into a wide U shape.
2. Drill small holes at both ends of the U tips.
3. Thread a strong, thin solid core wire through both tip holes and back through the center of the U — this wire controls the grip.

2. Mount the Claw:

1. Attach the base of the U-shaped claw to the vertical arm segment.
2. Make sure it’s secure and aligned so the tips move symmetrically when pulled.

3. Connect the Servo Pull Wire:

1. Attach one end of the pulling wire to a servo horn mounted on a small servo (connected to Ch4 on your receiver).
2. When the servo rotates, it pulls the wire, which contracts the claw tips inward.
3. When the servo returns, the U shape’s natural flexibility lets the tips spring back open.

4. Test the Mechanism:

1. Power the servo and test claw operation with your transmitter:
2. Pulls tight to grip objects.
3. Releases to open back up.
4. If needed, adjust the tension or anchor points for smoother action.

5. Fine-Tuning:

1. Ensure the wire has a smooth path and doesn’t snag.
2. Add heat shrink or glue to keep knots from slipping off the servo horn or claw tips.
3. Test gripping small objects to ensure proper tension and return motion.

At this stage, your RC tank build is complete! All major components—chassis, motor wiring, RC receiver setup, arm base, servo-controlled arm, and wire-tension claw—should be fully assembled and connected.

1. Power on the system using your battery pack.

1. Test movement using your Hot RC transmitter, Forward, backward, left, and right motor control.

1. Test the servos:
2. Arm should lift and lower smoothly.
3. Claw should open and close when triggered.

1. Check all wiring for stability, signal, and neat routing.

1. Inspect the structure:
2. Ensure the base and cover are secure.
3. Look for any loose parts, obstructions, or unbalanced areas.

1. Try picking up an object to verify the claw and arm combo is functional.

Add some eyes or a smile, and you're done!