Two emergency stop buttons?

I’ve currently got a fancy emergency stop big red button on my DIY printer, but I was just thinking it would be nice to have a hard switch that gets hit if my Orion piezo sensor doesn’t work for some reason (though it has been super reliable). I’d hate to think what would happen as it keeps raising the platform up into the carriage. Just to make sure I’m not overthinking this: The smoothie config is currently set for normally closed operation on the emergency stop, so if wire in the 2nd switch on the Z axis as normally closed I can just wire the switches in series when plugging into the smoothie, right? (I have this tendency to overthink everything and get in trouble, but this seems right to me).

makes sense. We normally use the ‘NC’ configuration so even a broken wire, connector, etc will trigger the event. Putting another safety switch inline is a good implementation.

Sounds right to me too!