Modular robot platform

Hi, this is a work in progress project of a modular rolling robot platform.

**The idea is to provide :**
- a standard modular chassis
- a set of "heads" (brackets) for different front sensors
- a few variations of the rear caster
- various wheel designs
- adapter plates for different electronics boards (PICAXE, Arduino, Raspberry Pi..)
- space for batteries under the chassis
- some kind of front gripper or arm
- an hexapod kit

**Versions**
- Standard size is 75mm wide by 130mm lon