When making a telescope mirror on the machine, two parameters are important: the rotation speed of the mirror, and the rotation speed of the overarm eccentric. Other environmental parameters also matter: temperature and humidity are foremost here. To more easily monitor and display these variables, I've built an electronic device that collects this data and shows it on the control panel. This is how to build the device.

Note - this blog post got noticed and was reprinted by EarthSky:

https://earthsky.org/brightest-stars/how-to-observe-sirius-b/

Sirius is the brightest star in the night sky, visible anywhere on Earth except the far North. If you live in the northern hemisphere at a temperate latitude, Sirius is that very bright white star due south every winter in the evening. But did you know that Sirius is also a double star? The companion, Sirius B, also known as The Pup, is a very small star orbiting the primary, and can be seen using amateur telescopes, even small ones. It's not an easy observation to make, but it can be done if you follow certain guidelines. Here's how to do it.