I completed the $14.57 two wheel drive chassis this evening. The parts take about 1.5 hours to assemble and were a good lesson in mechanical engineering. The DC motors come with a 20 hole decoder wheels for a speed counter. The battery pack holds 4 1.5 V AA batteries. (I wonder if that will be powerful enough for me). The front wheel looks like a castor used in the furniture industry. All the parts were complete as received, and I think it would be hard to get the equivalent for any cheaper. I plan to modify the top to receive the Arduino Starter board and will show your later after a couple simple screw modifications. I almost forgot to remove the paper cover from the encoding wheel, but it look much better without the protective cover. The paper instruction were in Chinese with pictures, and managed just fine with the image. I did put one motor in reverse and corrected it later. A soldering iron was needed. The DC motor comes geared down for toy car use.
