Introduction: Car No. 05 First Stage

Car No.05 is the project aiming to make a programmed automatic driving car.

This project consists of several stages from assembling of modified chassis to the trial of various versions of control system.

As a first stage of Car No.05, assemble a smaller turning radius R/C chassis modifying Tamiya M-03R chassis x 2 units, and make a relation table between steering servo value(steval) and turning radius(R, TR) in Excel sheet.

Step 1: Procurement

R/C Car

- ChassisTamiya M-03R chassis x 2

- Motor380 motor x 1

- Attaching JigKawada B57

- ServoFutaba S3003 x 2

- Speed ControllerTamiya TEU-104BK

- NI-Cd Battery for R/C Car  7.2V 1300mAh

- Plarepair

Measuring a turning radius, following devices are also required.

- Arduino Duemilanove

- Arduino ProtoShield KitDEV-07914

- Bluetooth ModemBlueSMiRF

- 5V 500mA Batteryeneloop mobile booster KBC-L3ASor006P Nickel hydride batteryGP20R8H 200mAh 8.4V

- Bluetooth USB AdaptorParani-UD100

Step 2: Assembling

2 pair of A1 and A2 parts shall be cut at center of battery holder and glued with plarepair.

Get the center value of servos and set up the speed controller. (Refer to Car No.02 or Car No.03 of my Instructables.)

Assemble in accordance with Assembly Manual.

Attach Arduino+ProtoShield+Bluetooth Modem and eneloop battery or 006P battery with double-faced adhesive tape temporary, and wire/connect.

Body will be attached in Third Stage.

Step 3: Relationship Table Between Steering Servo Value and Turning Radius

Upload the attached Arduino code.

Arduino code


Run the attached Processing code.

Processing code


Measure a turning radius relative to a steering servo value.

Original M-03R’s wheel base is 210mm. Approx. 200mm turning radius R/C Car is now available.

Change a steering servo value by pressing ‘right‘ and/or ‘left’ arrow keys, and remeasure a relative turning radius.

The attached Excel sheet shows a relationship between steering servo value and turning radius. (Refer to “TR” Worksheet and “Fig1,2,3” Worksheets for car plan drawings and A, B, C, D, E, F, G points.)

This sheet is already adjusted based on the measuring result.

(ZBR0 and ZBL0 are adjusted to meet with the measuring result as much as possible.)

Then, make the relationship table between steval (steering servo value) and R, TR (turning radius).
The table is in ‘Table’ Worksheet.

Step 4: To Be Continued

In Car No.05 Second Stage, utilize the obtained relationship table and make an Excel simulation program, to which car starting point, car starting direction and pass points are input, then from which steval and car direction are obtained as automatic driving data.