If your new to CNC milling try to find an down cut end mill if your machining plywood. It will prevent the top layer of ply being ripped off the plywood. I found and upcut tore the outside layer out sometimes in chunks other times in huge splinters. This was in Baltic Birch plywood so I had to order Down cut spiral 2 flute bits. It will save you a lot of frustration. Hope this helps you out.