Danger as a Teaching Mechanism

This post from Ron Pihlgren was good for a laugh and could've only been better with a picture of the apparatus in question:

Danger as a Teaching Mechanism

We loaded the program and ran it. All 3 axes moved to the home position and the table started moving along the major axis. The table was traveling at a pretty good pace. As the tool carrier reached the end of the table I found out what happens when a few hundred pound object moving at a rapid speed hits the end of its travel without decelerating...

Most of my engineering-gone-awry stories occurred while I was in the Navy. For example, once I was working on an automatic bus transfer device (automatically switch power supplies, not bus routes) for a pump. Part of the job included testing the control circuitry. It's been 15+ years and the details are a bit fuzzy, but I vaguely remember that I was supposed to attach an AC source to the AC input of the control circuit. For some reason, I misread the diagram and I attached AC to the DC side of the circuit. Needless to say, components in a low-voltage DC circuit don't respond well to 120 volts of AC. In particular, electrolytic capacitors tend to die horrible deaths as they short-out and fry.

Practical considerations - Chapter 13: CAPACITORS - Volume I - DC

Capacitors, like all electrical components, have limitations which must be respected for the sake of reliability and proper circuit operation.