I needed some compact rods for measuring the depth of bored and drilled holes. Mostly for the lathe but you can use them just about anywhere. They are not the most accurate device but they will fit where other depth mikes or calipers won't fit. I still need to make some rod ends. One will be just a steel cylinder with a square end and the other type will be a steel cylinder with a 118 degree point to simulate a drill bit.
Very simple to make. Just some all thread, rod couplings and some knurled nuts. You could use hex nuts for a really fast build but then you need some tools to set them with.