Mechanics of the e-puck

Simple mechanics

To reach the goals of the project (low price and robustness) the mechanics has to be very simple and elegant. The structure has been therefore based on one single part (followings pictures) ensuring the structure of the whole robot.

This basic part has a diameter of 70 mm and ensures the support of the motors, the printed circuit and the battery. The battery is located under the motors and is connected to the printed circuit by two vertical contacts. The battery can be easily extracted and recharged externally.

Motor

The choice of the motors is crucial for this purpose. On the e-puck design we decided to use miniature steppers motors with gear reduction. The motor has 20 steps per revolution and the gear has a reduction of 50:1. The final axis is sufficiently strong to support directly the wheel.

Wheels

The wheels diameter is about 41 mm.  The fixation is made by a four teeth chuck. There is a bras peaces insert in the plastical wheele. A green o ring is used as tire. The distance between the wheels (mounted) is about 53 mm. The maximum speed of the wheels is about 1000 steps / s, which corresponds to one wheel revolution per second.