Tamiya 75020 Line Tracing Snail Kit

Overview

The Line Tracing Snail uses a infrared LED and a photo transistor to detect a black line (magic marker, electrical tape, etc.) drawn on a white background. It uses two small motors and rubber tires to slowly but surely follow the line. The body of the snail is made of transparent plastic to allow viewing of the mechanisms inside.

To follow a line, the snail emits infrared light from the an LED on the underside of its chassis. A photo transistor picks up the reflection of the infrared light to distinguish black from white surface. A potentiometer allows you to adjust the transistor sensitivity for various surface types and line widths. The snail’s speed is controlled with a switch. It has a low-speed mode suitable for fine lines and narrow areas and a high-speed that works best for wide areas and thick lines.

To assemble this kit you will need a modeling knife, screwdriver, diagonal cutters, and long nose pliers.