During grad school, back in the early '80s, I spent a couple of terms off just earning some dough. I worked in a "startup" machine shop. The owner had some old metal punch presses that at one time had been powered by steam engines (or maybe even waterwheels) which pulled long leather belts throughout the factory building. These turned smaller transfer stations from which smaller belts ran to the press and turned a pulley. The presses had been modified with electric motors bolted to the top and a short belt running between the motor and the original pulley on the press. On the back of the presses themselves, we found manufacturing dates stamped on the body. I could hardly believe what I saw: 1860's and 70's.
These things had been jerry rigged with "safety buttons". The operator was supposed to hold one button down with his right hand and another with the left hand for the thing to run.
One problem was that the die wouldn't always punch cut the sheet metal correctly and they would hang up inside the die. The shop owner had us mash the buttons down with our elbows and keep a 1" x 2" x 6" stick in the right hand. In the half second intervals between punches, we had to quickly flick our wrists, using the stick to knock the part out from between the upper and lower sections of the die. The bigger problem was that the gearwheels inside the mechanisms were so worn out that the press would sometimes miss a beat and then double punch in less than a tenth of a second. Several times a day, the other half of that stick would have its thickness reduced to the same as a sheet of paper. A couple of years later, I ran into some of the guys I'd worked with in that place. To borrow a term from mathematics, they both were missing some "significant digits."