Getting closer. Haven’t destroyed a bit yet so thats good.
2 pieces on the left are 3/16 mild steel.
180hz on spindle (not sure what exact rpm but should be around 10k)
3 flute 1/8in end mill
.5deg ramp angle
1 additional roughing pass
Its pretty close to my settings for aluminum just 3 flute instead of 2.
I did notice that cutting the holes was better at 600mm/min, but the outer contour path that was too fast.