Variant Chassis for Drawing Bot

Variant chassis file for the incredibly well designed Arduino Drawing Robot made by MakersBox: http://www.instructables.com/id/Arduino-Drawing-Robot/

I plan on using this in a class environment so I needed to get costs down as much as possible so I modified the design to be able to:

- Use the mini breadboards we already have (will also accept any standard half board)
- Use the battery packs we had on hand (2xAA and 3xAAA)
- Use 5/8" bearing casters I found cheap