I would start off slowly and work your way up. A good start would be about 8,000 - 10,000RPM and a 100 mm/min ( 1.6 mm/sec) feed rate. I would advise that you use a cutting medium like kerosine or WD-40 in a spray bottle. If you can get your hands on a good soluable oil (hard to find in Europe), that would work as well. If your machine is not vibrating at the above speeds and feeds, then you can try increasing your feedrate, if your machine is vibrating, either drop your feed rate or increase your spindle speed. Remember if you are direct plunging, do not plunge at the same feed rate you are cutting at, try 25 - 50 mm/min (0.4 - 0.8 mm/sec) for plunging. Let us all know how you went.