I have an embroidery machine that requires that the "top tension" and "bottom tension" of the threads involved be calibrated very carefully. Today, I do this with a small pen shaped device called a "Tension Gauge".
The way that it is used is that you disconnect the thread from the needle, tie it to the end of a hook that is attached to a spring with a needle on it, and you pull on it. The thread will pull down the spring until it reaches the point where the spring pulls back, and then the tension of the thread is measured.
I would like to try and build this with an Arduino and have it be digital. I don't believe that this is a complicated build, but I don't know what type of external sensor I can use to work with the Arduino board. Can someone provide me with some guidance on how to get started and any reference material.
-Squeed