Cardboard Bot

thingiverse

Parametric base, sides, and wheels for a robot made from cardboard. Easy to make and super cheap to remake if it gets destroyed in a robot battle! Open in customizer to experiment with different widths, lengths, heights, wheel sizes and the position of the wheels front to back. Switch the view to dxf to make a laser cutter outline. The extra cardboard can be used to make cross braces to strengthen the body. The main motivation for writing this as a script was to make it easy to play with different sizes and still have a very accurate alignment so it can use regular DC motors, with the motor shaft rubbing against the edge of the wheel to turn it. Stretch a fat rubber band over the wheel (size the wheels for the rubber band) and the motor shaft will make solid contact. The small "washers" have different sized holes in them. The larger hole washer is glued to the wheel before slipping over the axle during assembly. It spaces the wheel away from the body, and helps keep it on the shaft. If you use RC servos, or gearmotors, just ignore the upper motor holes or set the motor sizes to 0. Honestly, you probably don't need this script then. A good motor / controller / firmware package for a robot like this can be found here: https://github.com/jmalins/BattleBot-Control Update: Added a pattern of slots to the wheel to support detection of wheel movement for feedback to the controller, allowing precise movement... a low resolution servo encoder. The simplest form of this would be a bare wire, wound in and out between the slots, with a pair of wires from the side that are shorted by that wire when the wheel turns. TODO: Cut one and see how it works, adjust, iterate. Especially the crease parameter to see if it can be turned into a score rather than a cut. A stiff, thin cardboard is best, like that used for Priority Mail boxes. (Disclaimer: Actually using a priority mail box to make a robot would violate federal law) To often, students are motivated to avoid failure at all cost. This is especially evident in high cost, high tech activities like robotics. Making a simple, but precise robot body out of cardboard, for use with ultra low cost DC motors, H-bridge driver, and the ESP-8266 for wifi radio control (programmable in Arduino IDE). By using cardboard as the primary material for the body, it can be replaced for a few cents and in a few minutes which allows the class to experiment freely and not be afraid of failing. Now you can try things, work with ideas, and if it doesn't turn out as expected, your time and materials will be minimal. "Fail Early, Fail Often, Learn from Failure, Stop Failing."