Scrimper.
Being an industrial electrical engineer all of my working life, I have a thing about NVR’s and machinery.
My last nine years of employment was spent as the site electrical engineer and electrical duty holder, for a large factory.
99% of commercial/industrial machines are fitted with NVR at manufacture, and prominent emergency stop buttons fitted.
But I also installed a life line system, this is a line running just above head height across the production area, when pulled it operates a switch, which drops the main supply contactor for that production area, it means, if you see somebody in trouble, you don’t have to get to their machines emergency stop button, you just reach up and give the life line a pull. Disadvantage all machines in that area stop.
In the home/hobby environment it’s a bit different, number one you are probably on your own, and you alone are responsible for your own safety. This is were a dead mans switch is advantageous.
The main advantage of a NVR on a machine, in the home workshop is, if you have a supply trip go or a mains supply failure, any equipment you were operating at the time, defaults to the off state, (will not restart on its own, when power is restored).
Sorry, you got me up on my soap box. (hammer)
You are correct, the powered fret/scroll saw, is probably one of the safest cutting machines in the home workshop, I like you have never cut myself on the scroll saw, after many years of use, famous last words.
See you in A&E tomorrow, the first one there, save a place for the other. :roll:
All the best.
Chris R.