Hi everybody.

I have a 3016 HT -97 with 32MP controller and I have run in to a little problem.

I am trying to run 6082-T6 aluminium at 450mm/min with a 6mm 3-flute carbide aluminium end mill running at 7500 or 9500 rpm.

When I make small circular ( 6.5 - 15mm ) interpolations the surface is very good you barely could see the tool marks, but when the diameters get bigger the surface finish get worse and almost look faceted.
I have tried to speed up the feed and then lowering the feed, taking small finish cuts with depth of cut 0.2mm or large 1mm, I have even tried to do the operation with a larger tool 12mm and 50mm but it stays the same.

The dimensions of the milled parts is very good and even , +- 0.01mm to +-0.02mm and the work-holding is very solid and rigid and there is no or very little vibration noises when running and the cutting fluid is plentiful.

I am very thankful for all help.

Best Regards.
Fredrik