LEGO Mechanical Speed-Graphing System

When it comes to measuring rotational speed mechanically, without the use of electronics, the simplest and most elegant mechanisms are the Watt governor and Hartnell governor, both of which use hanging weights that are free to swing outwards at high speeds. However, after some testing, I could see that the accuracy and precision of these mechanisms weren't always great, so I started looking at other potential ideas.

This led me to building a machine that uses a pendulum timer to time the rotations of a motor (or other rotating input) to determine its speed. After some improvements, this machine ended up working really well. It's only drawback compared to the Watt and Hartnell governors was that it only showed the average speed over the measuring time period, instead of showing the speed in real-time. My solution to this was to add a speed-graphing machine to the timing machine. This allowed the machine to plot the variations in the input speed over time, and I was really surprised that it ended up working as well as it did. Enjoy the video!