Wireless Lego Race Car

Lego Bricks are great to use as a sketch tool. I can build a mock up, then tear it down. I can create different designs, if it didn't worked I can tear them down and rebuild another model without wasting anything. Or I would build two models at the same time and compare them side by side, and see which one will work better.

This instructable shows you how I used Lego Bricks and components to design Lego Race Car.

My Lego Race Car using different wheels sizes for the front and rear. My Lego Race Car did not have front wing flap, similar to some Formula 1 race cars in 1960s.

This Lego Race Car did not used all Lego's parts. I built this one the same way I built my R/C Lego Car. A small servo was used as the turning mechanism. And I used motor and gearbox with axle that I took out from small R/C car.

When I first started building this car. I thought of using XBee module to wirelessly receive commands from PC or Laptop. (See test video in Step 13). After I finished the car I thought of using RN-XV WiFly module to receive commands from my iPod touch.

The reason to use iPod Touch (4G) as a remote control device instead of using the laptop or PC to control the car. Since the iPod Touch (or iPhone) is so small that I can hold in my hand(s), I could move around to follow the car instead of sitting at the same place with a laptop sit on my lap.

Here is how I created this Wireless Lego Race Car.

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Step 1: Parts and Tools

Following is the list of Lego Technic parts that I used for building this R/C Lego Race Car.

If you want to do this project you could use the differenct color for the car.

Note: The number in the bracket is the Lego's Design ID.

3 no. - Technic Plate 2x8 (#3738)
1 no. - Technic Plate 2x6 (#32001)
2 no. - Technic Plate 2x4 (#3709b)

2 no. - Plate 1x8 (#3460)
5 no. - Plate 1x6 (#3666)
3 no. - Plate 1x4 (#3710)
1 no. - Plate 1x3 (#3623)
2 no. - Plate 1x2 (#3023)
4 no. - Plate 1x1 Transparent (#30008)

4 no. - Technic Brick Angular 1x1 (#4070)
1 no. - Technic Brick 1x2 with 2 Holes (#32000)
4 no. - Technic Brick 1x2 (#3700)

9 no. - Technic Brick 1x4(#3701) , 4 Red, 3 Grey, and 2 Black
3 no. - Technic Brick 1x6 (#3894)
4 no. - Technic Brick 1x8 (#3702)
4 no. - Technic Brick 1x12 (#3895)
2 no. - Technic Brick 1x16 (#3703)

2 no. - Slanted Brick1x6 (#2744)

6 no. - Connector Peg (#3673)
10 no. - Connector Peg With Friction (#2780)
8 no. - Connector Peg with Cross Axle (#6562)
4 no. - Connector Peg with Knob (#4274) 2 Grey, and 2 Blue
6 no. - 3M Connector Peg (#32556)
4 no. - Bush for Cross Axle (#6590)

1 no. - 2M Cross Axle with Groove (#32062)
3 no. - Cross Axle 6M (#3706)

Steering Kit

Steering Gear Holder(#2790)
Steering Rack (#2791)
Steering Rack Top (#2792)
Steering Rack Bracket 8 pin Plate T37 (#4262)
Steering Arm Drop Link (#4261)
8 Tooth Gear (#3647)

2 nos. - Cross Axle 3 with Knob (#6587)
1 no. - 1/2 Bush (#32123)
1 no. - 1x4 Flat Tile (#2431, not shown in the picture)

Wheels and Rims
Front
2 no. - Tire size 30.4 x 14 VR (#6578)
2 no. - Wheel size 30.4 x 14 VR (#2994)

Rear
2 no. - Tire size 43.2 x 22 ZR (#44309)
2 no. - Reinforced Rim with no pin holes 30.4mm D x 20 mm (#56145)

Rear Wing Flap
1 no. - Panel Fairing #5 (#32527)
1 no. - Panel Fairing #6 (#32528)
2 no. - Lift arm 3 x 5 L-Shape with Quarter Ellipse Thin (#32250)
1 no. - Lift arm 3x3 (#32249)
2 no. - Lift arm 2x4 L shape (#32140)

Servo
9g Micro Servo (T Pro SG90)
This servo is controlling the front wheels turn.

Motor
I got the motor with the worm gear and enclosure from an old 1:18 Scale R/C car.
This motor is driving the car forward and backward.

Others
Arduino or Arduino compatible (I used DIY Arduino in this project.)
L293D (or SN754410) motors driver IC
RN-XV WiFly module
Xbee breakout board (For RN_XV WiFly module (I used XB-Buddy Basic Kit, Jameco's Part no. 2163680)
PCB (approximately 2"x3")
Hook up Wire

Tools
Super Glue
X-ACTO Knife
Sand paper
Files
Hand Drill & bits