I have a new project that calls for more than 200+ holes cut into 25mm thick baltic birch plywood, for each platform. My overall project calls for more than 100 of these decks, so lots of hole cutting!
I created a prototype using a down-cut spiral end mill bit, I believe it was 3/8" in cutting diameter. However, it left burn marks at the bottom of each 1/2" hole. I've since been told that "3D entry" could resolve this issue, but I'm sure if my friend's CAM software supports that. The bottom of all holes must be flat.
One other note: I also need to cut sub-holes inside these 1/2" holes that will be 1/4" in diameter. We do have a dual-spindle, so I can configure these smaller holes to be cut with a smaller bit.
In general, I guess I'm just wondering what the perfect bit would be for this kind of application. And any idea of how much mileage I will get out of each cutter before they need to be tossed or resharpened?
Thanks!