Sorry, I should have posted full details with the picture.
There were no tool changes and the cutter was 3.5 mm diameter as the one on the right in the picture here :-
http://www.flickr.com/photos/22267456@N05/2547381165/However, I reground the end to make it more of a 'ball nosed shape' ( this took some time to do as the cutter is solid carbide and I do not have a diamond wheel ). The feed rate was F450 and the spindle speed was 3000 rpm. I took approx. 1 hour to cut.
Thanks to everyone for looking at my postings, I hope they have been of interest.
Tweakie.