One never stops learning! Although I have been working on airplanes most of my life, I still smile when I get to learn something new--which is almost every day, as the building world is huge, and the amount of accumulated experience and knowledge vast beyond comprehension. Take, for instance, this neat little tool--an optical center punch.
I am sure that the machinists among our audience will say “oh that? I use one every day!” But I somehow had never encountered one until a friend showed me just how he locates holes with unbelievable accuracy. I am used to measuring for a hole, drawing two fine, intersecting lines, then using a mechanical center punch carefully placed to make a dent for my drill bit. The optical center punch makes the punched spot an order of magnitude more precise. You peer through a magnifying lens inserted in a hole drilled all the way through the black base of the device. The lens has a dot, or a pair of cross hairs (depending on the model you have), and you center it up on your measured spot, which is highly magnified. When you have the tool centered, you pull out the lens, insert a steel center punch in the now centered tool’s hole, and give it a little tap with the hammer.
Voilà! A perfectly marked hole in which to start your drill!
I’m gonna have to get me one of these things.