Thanks to all

I used a 6 mm endmill to create the flat as suggestedand then drilled the 4.8mm for theholesaw center drill. This gave me the perfect start for the 55 deg hole. Then the problem with the "waste center bit" was encountered. thanks for that advice. Ended up cutting the hole then at 90Deg to get rid of the waste. then the "guide" constructed to guide the drilling machine helped to clear the last little bit of waste on the other side bottom.

So can see I had to use a bit of everybodies advice for this job.

THANKS