E-stop in case of Z probing failure

[dandancheeseandham]

Head crashes seem to be the major worry for people.

So how about micro-switch emergency stop on the print head, in a location 1mm lower than the users existing probe.

Bonus points for adding 2 more micro-switches in series:

• one located at Z max , so if Z max is exceeded somehow (this is pretty optional and almost certainly unneeded)
• one as an emergency stop button on the frame (this is optional, but seems quite nice)

What type of emergency stop is up for debate. However with RTOS I'm fairly happy with just triggering M112/M999.

[TheeDynamikOne]

I think the best solution for this would be an Emergency stop button, just like other machines that can damage themselves when things go wrong. Adding redundancy is a slippery slope when you're also adding the possibility of another failure mode.

[lostapathy]

Adding redundancy is a slippery slope when you're also adding the possibility of another failure mode.

To be fair, so long as the e-stops are wired in series and normally closed, you'd fail stopped rather than "fail to stop", which is perfectly ok.