can any please tell me what the corrrect speed and feed rates to cut .04" depth at a time with a 4 flute center cutting 1/8' end mill in .025" polycarbonate (single pass), thanks, for help Tj

I would not even try with a four flute. In my experience the best for polycarbonate is a new two flute high helix so the chip is curled up out of the cut. I have never gone as small as 1/8" but have taken a 1/4" two flute through 1/4" polycarbonate full depth at 10,000 rpm and 200 ipm with flood coolant.