I would not recommend ramping small cutters at all(mostly in metal) but ramping bigger ones that can take the side load and the load from plunging can handle it. I have ramped my 1/2" and other end mills larger than 1/4 quite a bit, but when it comes to ramping something like a 1/8" end mill, I burned it up good.
You should not plunge at the same speed you feed at, its actually quite a bit less.
On my mill I plunge 1/16" end mills at 1ipm in copper, 1/8" end mills between 1 and 3ipm, and because my machine cant handle much more on bigger cutters(1/4" I sometimes get away with 5ipm) but depending on the cutter, you can plunge quite a bit faster with say a 1/2" 3fl in aluminum. I have actualy seen/heard(yeah it was noisy) a 1/2" endmill plunge at 40ipm in aluminum, it managed to do it on a Haas, but not likely on much else(nor with a diff end mill).
Jon
|