Beginner Friendly and Cost Efficient RC Car

Project Overview

Materials

4 Jumbo Popsicle Sticks
2 Thin Skewers (2.5mm dia)
4 Wheels (42mm dia)
3V DC Motor
2 AA Batteries + Holder
RF Receiver & Transmitter Circuits (GS-170TX2A)
3D Printed Gears (Drive & Stopper)
1 Regular Straw & 1 Bubble Tea Straw
Loom Band Elastics
Googly Eyes (Optional)
Tools: Ruler, Wire Strippers, Scissors, Hot Glue

Quick Stats

Target Cost: ~$9.36
Build Time: ~3.5 Hours
Complexity: Level 1 (Beginner)
Required: 3D Printer
Required: Soldering Iron (Semi-Optional)

Demo Video

Prototypes

The final design was the result of 6 major iterations, refining chassis stability and axle friction to ensure a reliable build that could be completed by students within the camp timeframe.

Prototype Iterations — Evolution from early popsicle stick experiments to the final standardized design.

3D Print Files

Download the STL files for the custom drive gears.

Download Drive Gears (.STL)

Part 1: The Car

Materials Overview

Ensure you have the following components ready for the car assembly:

4 Jumbo Popsicle Sticks
8” Plastic Straw
3V DC Motor
2 AA Batteries & Holder
2 Thin Skewers (6”)
4 Wheels (42mm)
Loom Band Elastics
RF Receiver
3D Printed Wheel Gears
Bubble Tea Straw (1)
Googly Eyes (2)

(The thick skewer shown in the photo is used for the controller, not the car.)

Building the Chassis & Axles

**Step 1:** Take one of the large popsicle sticks and snap it in half. Try and be as precise as possible.

**Step 2:** Take 2 more full sticks and hot glue the halves parallel, making a box 1 by 1/2 sticks.

**Step 3:** Take the last large popsicle stick and snap it in half too.

**Step 4:** Hot glue the half stick across at 8-9cm. Ensure the pieces are level.

**Step 5:** Flip the base over. Hot glue the last half stick 5cm from the bottom.

**Step 6:** Cut thin skewers at 12cm. Do not hot glue these!

**Step 7:** Cut straw into 2 pieces matching the shorter stick length.

**Step 8:** Take 2 wheels, 1 skewer and the straw.

**Step 9:** Attach wheels to the skewer.

**Step 10:** Cut the straw to ~11.5cm (the length of the axle assembly).

**Step 11:** Trim another 0.5cm so the straw doesn\u0027t touch the wheels.

**Step 12:** Slide the straw on. Ensure it doesn\u0027t create friction against the wheels.

Front Wheel Assembly

**Step 13:** Gather the 3D printed wheel, remaining wheels, straw pieces, and elastic.

**Step 14:** Attach the elastic to the 3D printed wheel.

**Step 15:** Attach the skewer to one of the wheels.

**Step 16:** Slide a straw piece on. It should be loose and free-moving.

Step 17 — **17:** Slide on the 3D wheel.

Step 18 — **18:** Add the last straw and wheel.

Mounting Components

**Step 20:** Glue the DC motor across the sticks. Keep copper connections facing up.

**Step 21:** Place the small 3D wheel on the motor shaft. Glue the tip if loose.

**Step 22:** Glue the battery holder to the gap on the left. Watch the wiring.

**Step 23:** Secure RF board wire bases with hot glue to prevent breakage.

**Step 24:** Strip red, black, short white, and green wires. Be extremely careful.

**Step 25:** Glue the board so motor wires are positioned for easy connection.

Wiring & Electrical

**Step 26:** Twist power wires together from battery and circuit.

**Step 27:** Use electrical tape to insulate the power connections.

**Step 28:** Thread and twist wires through the motor terminals.

**Step 29:** Secure motor connections with hot glue or solder for reliability.

**Step 30:** Test power. Red LEDs should light up when the switch is flipped.

**Step 31:** Power the transmitter with the 3V coin battery to test F/B controls.

Final Car Assembly

**Step 32:** Verify motor spin. Troubleshoot connections if it doesn\u0027t activate.

**Step 33:** Position the long white antenna wire facing upward.

**Step 34:** Glue back wheels. ONLY glue the straw, never the skewer or wheels.

**Step 35:** Mount front wheels. Ensure no glue touches moving parts.

**Step 36:** Hook the elastic from the 3D wheel onto the motor shaft.

**Step 37:** Center everything and add a small drop of glue to lock the 3D wheel to the axle.

Part 2: The Controller

Materials Overview

Gather the following components for the controller assembly:

RF Transmitter Circuit
Stiff Copper Wire (12cm)
CR2032 Coin Battery
2 Brass Fasteners
Tools: Wire Strippers, Skewer (4mm), Hot Glue, Ruler, Tape

Antenna & Body Construction

Your Mission

You've built a functional, AA battery powered vehicle that can zip forward and backward. But a truly great engineer never stops at just "functional." Currently, this car is limited to a single axis of motion.

The Challenge: Design and implement a steering system.

How could you pivot the front axle while maintaining structural integrity?
Can you utilize a second motor or a servo to control the direction?
How would you modify the RF controller to handle left and right commands?

Take the foundation you've built here and make it steerable. The best designs often come from the simplest materials!