Harry Bloomfield has brought this to us :
I've just bought one of these and I'll be darned if I can follow the supplied
instructions for setting the drill bits up in the holder. If I push it in to
the setting guide far enough to touch the metal pin, it seems to then be too
close to the wheel when inserted for grinding - so would take far too much
off.

I have managed to sharpen a few bits, but by trial and error setting.

Its this one..
https://www.youtube.com/watch?v=ToN4LDtESp4