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 long
- Narrow size is 56mm wide by 130mm long


- v0_0 is a first release without any mounting holes for the electronics
- v0_1 includes holes for Arduino Uno R3, Picaxe 28x2, 28x1 and 08 project boards.

**BOM**
- a pair of "continuous rotation" mini servos. They can be bought as is or you can make the mod yourself **See the attached PDF** it contains a step-by-step procedure I've written ages ago
- a standard SG90 micro servo for the head, a pair if you want to use the pan/tilt bracket