Not so tight that you break the wrench
The trouble with overtightening a Morse taper is that you end up banging harder than you want to on the end of the drawbar to get the thing out.
Hehe ;p
I had been showing my friend how to use it as he wanted something done and I can't stand up to long at the moment as I've just had my ankle replaced. I'd shown him to loosen it till it bites again then a quick wack to free it up but he forgot the wack, oh well

So a knob it is then, I'm not even going to knurl it so it stops me tightening to far.
This is the kind of silly thing having someone to show you and ask questions of would avoid, I've spent an awful lot of time reading forums, asking questions and sucking n seeing but you still get some plain simple things wrong.....well I do ;)
So on that note, if there's anyone essex/london way who fancies a cup of tea and a chat let me know

Thanks for the help guys.