This small mechanical revolutions counter was built to determine how fast a small steam engine, electric motor, or machine tool spindle is running. It uses a worm shaft and round gear with a 100:1 ratio. By timing ten rotations of the dial face with a stopwatch and dividing the number of minutes, it’s fairly easy to determine the rpm of any rotating object. The stand helps to align the device with the rotating shaft. Plans for this mechanical revolutions counter can be found in volume three of The Shop Wisdom of Rudy Kouhoupt.
One of the first large donations to the Miniature Engineering Craftsmanship Museum was the collection of famed model engine builder Rudy Kouhoupt. Rudy’s niece, Susan Alvaro, was kind enough to donate his entire lifetime engine collection for display at the grand opening of the museum in 2006. After retiring as a chemist, Rudy had a second career building engines and writing magazine articles documenting the process. Many people have built his models, but we have the honor of displaying all of his original prototypes. Rudy’s collection includes scale model engines, locomotives, tractors and more. Additionally, thirteen of Rudy’s model steam engines are hooked up to run on compressed air to demonstrate their function.
