Fuck!
I just broke my edge finder.
Switched on the spindle and it was still set to way too many RPMs.
(tried to find the exact center of rotation to start milling)
New ones all seem to be 10mm shank for mechanical and 20mm for cool opto-electronic ones.
The ,maximum I can mount is 7mm. 
Bugger, I feel your frustration Marcus. Hope you find another one soon? Maybe someone could machine down a 10mm to 7mm (carbide or ceramic tip) and regrind it for you?
I found a 6mm one, no problem.
This is Germany after all. 
Engineering supplies are plenty…but expensive.
It’s 15eur where a 10mm one would have cost me 3eur.
That’s not too bad Marcus. Converted to Aussie dollars that approx $21.30. I actually paid that price for 20mm LED one for my mill. Is the one you bought made in Germany or China?
Breaking stuff is part of learning : P
Mechanical replacement arrived.
When the electronic one arrives I’ll have a close look for a way to make it work in smaller ER11 “hobby” CNC machines.