If you have a Tormach PCNC machine with their passive touch off probe you’re bound to break the tiny ceramic tip at some point. There’s two strategies, one is to buy a new one with a carbide or stainless steel tip but then if you crash it you might damage the probe itself – the alternative is to upgrade to a thicker boss by purchasing a non-Tormach replacement. Either of those doesn’t help you with your current problem – finishing the job you started with a non-broken tip!
I ended up trying to drill out the broken off chunk of ceramic with carbide tooling but to no avail. What did work great was heating up the probe tip with the broken ceramic stuck in it with a propane torch, the glue burns off and the broken ceramic chunk will fall out. You can then superglue whatever you’ve got left of the tip back in. Of course you’d think this would mess up the precision of the tool but that’s why you have to calibrate the probe in the first place, because it’s not glued in precisely initially.
Once your probe breaks off:
Add heat with a propane/butane torch:
Reglue the remaining tip into the socket with some super glue:
Go forth and save your $90 on the replacement, at least for the first time until it ends up too short!