There’s an old saying that you should make things twice. Once to figure out how to build the thing, and again to build it the right way. [Pmbrunelle] must agree. His senior project in college was a machine to balance wheels. It was good enough for him to graduate, but he wanted it to be even better.
The original machine required observation of measurements on an oscilloscope and manual calculations. [Pmbrunelle] added an AVR micro, a better motor drive, and made a host of other improvements. As you can see in the video below, the machine works, but [Pmbrunelle] still wasn’t happy.
He’s started the Mark II version of the project that will be a start-from-scratch redesign. One goal is to make the process faster (it currently takes about 30 minutes per wheel, which seems like a lot unless you are using it for a unicycle).
In the most recent incarnation, the AVR takes the wheel radius and collected data and tells you where to put the weight and, of course, how much weight to use. The Mark II will reuse many of the components in the existing machine although one of the goals is to replace some hard-to-find parts with things that are more readily available.
We couldn’t help but wonder if you could make a micro version of this for Pinewood Derby service. Although [Pmbrunelle] is using this project to learn more about electronics, following it might teach you something about mechanical engineering.