It's best to use a v-bit cutter or a ball end mill. The level of the surface being engraved must be flat for the text to come out clean looking. If it isn't the text will be deeper in some areas than others. I always cut the surface to be engraved before actually engraving. That way I'm sure the text will look excellent. Because your only cutting at a very small diameter you should run the cutter at maximum speed. 20000 RPM is not to fast. I built a CNC router from scratch and have made lots of signs for people as well as contoured guitar bodies. Hope this helps you out
Willy |