Hello guys,
my motorized slide needs an energency shut down on both ends.
can you help me with an idea how to build a switch that opens a contact to break current?
it should be small, like a normal push switch for breadboards or 1-2Euro coins.
only problem: it has to withstand 200 degrees and should be minimum 1mm accurate-
things can be montaged on the slide and track as well.
greetings
Look for switches like these at Newark/Farnell/Element14, RS, whomever your favorite supplier is. Connect up the Common and NC (normally closed) contacts. Read their data sheet to see what temperature they are rated for.
Thanks this link is great - but i cant find any switched above 85 degrees.
so as in the topic mentioned, i want to build one myself.
i have excess to allmost all metals and tools.
200C or 200F? 200C is pretty darn hot! That's solder reflow temperature
You know the basics - spring to hold two contacts together, mechanical housing to hold them and let something external push them apart. Coil springs can also lose springiness at elevated temperatures - so you've got a good mechanical challenge on your hands.
Try looking at how this one is made
thank you sir 
Does the switch have to be inside the "hot" part? Could you instead extend a lever or plunger outside of the hot area to the actual switch - allowing you to use commonly available parts?
Think about it: Should the switch fail, and you have to replace it - you'll need to make another one...versus simply ordering an existing part.
Perhaps they make ceramic-bodied microswitches?
even a paperclip is fine, a piece of nylon, or a baking form and if a dc motor is used two diodes is enough