How to build a robot #1 - cheap cardboard box robot chassis build

Affordabot's cheap TI Launchpad box chassis.

This is the first in a series of posts chronicling the building of Affordabot.  My goal with Affordabot is to build a powerful mobile robot platform as simply and as cheaply as possible.  Affordabot will have a microcontroller, motor controller, gear motors, several ultrasonic sensors, an LCD display, and a speaker.  The target cost for Affordabot is under $50.

In this first installment, I'll be constructing the basic chassis of Affordabot using a cardboard box, a Tamiya twin-motor gearbox, wheels and tires, a caster wheel and zip ties.

Watch the video for more detailed instruction, but construction is pretty simple.  Cut holes in your box for the tires. Zip tie the motor to the box.  Zip tie the caster wheel to the box.  Route your motor wires through holes in the bottom of the box.

Parts used in this step:
TI MSP430 cardboard box - obviously, you can use any suitable box of your choosing.
Tamiya twin motor gearbox - $8.95 at Pololu - You will have to assemble this.  I recorded assembly of the Tamiya twin motor gearbox a few months back here.
Tamiya ball caster kit - $5.99 at Pololu - You can substitute this with almost anything with low friction if you like.  The ball caster kit I bought comes with two casters for that price.
Tamiya truck tire set - $4.10 at Pololu - This set comes with 4 wheels and tires.  These are made to fit perfectly on the twin motor gearbox axles.

Wires routed into the interior of the box.

Closeup of the Tamiya twin motor gearbox zip-tied to the box.  Holes had to be cut in the box to make room for the tires.

Completed chassis, including rear ball caster assembly.