Lesson 1 in Metalwork class when I was 12yrs old. And yes, the outcome was demonstrated and another lump taken out of the floor. I've used lathes on and off all my life, and have had my own in the garage for 30yrs. I can guarantee I've NEVER left the key in the chuck.
I have seen chuck keys fitted with a spring at the bottom meaning the key will not stay in the chuck without being pushed in. I have been known to launch a key across the workshop if I found it left in place. Saves it knocking lumps out of the bed
I served my apprenticeship at Rolls Royce 1971-4 One of the first things they showed us was a series of unsanitised films (no video back then) of workshop accidents. Scalpings/strangulations/crushings/amputations etc.. Scared the living shit out of us, but the message was well and truly received. 45 years in manufacturing industry thereafter proved that not everyone was similarly educated
[David Attenborough voice on] And here we see a big cat taking a drink of water in a local watering hole [/David Attenborough voice off]
I thought that, but as there's 4 items, including teapot, milk jug & sugar bowl -one of them must be a cup?
One lovely old boy comes to mind (they were all lovely old boys weren't they?) He had done the guard off/guillotine thing, it was only one hand and they didn't re-attach, he had his thumb still and was still doing the same job!* He was so matter-of-fact about what had happened that it was as though he hadn't even lost anything. Coincidentally he gave me a good life lesson without me even realising it. *exclamation mark because i was young enough to be surprised back then.