Tapered holes?

[zaebis]

I will soon need to open a good number of tapered holes on the mill 0.2-1.5" in diameter with a slight taper and as deep as 1". Gotta have smooth walls and be fairly accurate. Aluminum 6061. How?

[OKUMAN]

You should try a tappered EM.

[Trent Steel]

Yes, tapered endmill with circular interpolation is the fastest way on a 3-axis machine.

[Superman]

Yes, rough with a tapered endmill
if finishing with the same sort of tool and it's not good, try heading for a tapered reamer ( reverse helix for smooth walls, size and taper will be consistant )