Project: Small Dual Differential
After experimenting with the dual differential design presented in the Ferrari book we discovered that it resulted in a robot that was too top heavy. The placement of gears required the motors to sit rather high up and the most appropriate place for the RCX was on top of the motors. Most robots in FLL competitions require attachments to be mounted on top so clearly a smaller design would be better.

One of the coaches in the 2002 program found a web page at Dartmouth that contained a much smaller dual differential design. Sadly this page is no longer active and we do not have any attribution information. If anyone know who posted this design please let us know. Here is a photograph of the original design:

We modified the design slightly to get rid of the protuding beams at the top and to size the axles a bit more appropriately. Other than that the building instructions you will find here are quite faithful to the original.

As with all dual differential designs one motor is used to drive the wheels and another is used to provide an additive or subtractive force that causes the robot to turn. This is accomplished in this design by using a motor to drive the gears along the back and front of the robot chassis.

To build this dual differential robot you will need the following parts:

You will also need to figure out how to attach the motors and RCX - that part is left as an exercise for the builder. Click here to begin building this dual differential design.

Copyright © 2003, Hacienda Robotics Program.