This is one of the projects from my forthcoming book "Robotics: Discover the Science and Technology of the Future," coming in August 2012 from Nomad Press.

Since this is a book for kids ages 9-12 to use on their own (or teachers to use in the classroom), I was limited in what skills, tools, and materials I could use. No soldering, as much recycled/repurposed as possible, and as low-cost as possible.

I had hoped to be able to include at least one "real" robot-building project in there, but nothing fit within my parameters. However, this one came the closest -- reuse the sensors, motors and printed circuit board from an inexpensive ($12-$15) toy car (really a robot in disguise) and turn it into a different kind of robot.

My rationale is that it teaches the purpose and design of all the main components, while not requiring any major assembly. Although I re-used the car chassis, kids can just pull the whole thing out and install it in a robot body of their own design.

Bearing in mind that this project is about the level of my electronics expertise (and, I'm guessing, most elementary school teachers' as well), what do you think of it?

If you want to try it for yourself, the Doodle Track Car is available at toy stores, from doodletrackcar.com or http://amzn.to/sE4j7J.