Circular Scale

This is a simple round threaded indicator, numbered 0 to 9. I used it when I was testing how repeatable a TTP223 capacitive switch was. It divides the thread pitch of 1/32 inches into 10 so that the linear movement was 1/320 inches (almost 0.08mm) for every graduation.

The thread is 8-32 because that was the long screw I had on hand, with PLA it was very tight, it might be better to scale it up a few %. I just sized the thread with a tap after it was printed.

Depending on which way you put it into the screw it will count up or down as you turn the screw.

My filament was white and the markings are hard to see, I painted over it with a permanent marker and then rubbed it off with isopropyl alcohol to improve the visibility.

I printed with the writing upright so the spreading out on the bed didn't affect the marking too much.