Had to choose between a ball end mill and a bull nose for a 3D contour

Went with the 1/2 inch bull nose because the radius gave a better finish on the aluminum part's curved surface. Anyone have a go-to for finishing deep pockets without chatter?

3 comments

3 Comments

jackson.sarah3mo ago

Yeah, the bull nose radius is a game changer for finish on curves... but you mentioned deep pockets. How deep are we talking, and what's your machine's taper? I've had to switch to a stub length end mill and take crazy light finishing passes to stop chatter in a 3-inch deep pocket.

seth_green851mo ago

Three inches deep is where things get real, especially if you're running a 30 taper machine. I switched to a 1/2 inch diameter stub length with a 0.030 radius and it helped a ton. The key for me was programming a trochoidal toolpath for the roughing and then a really light finish pass at like 0.005 depth of cut. It took forever but the surface finish was glass. I'd rather take the extra time than fight chatter on every pass.

claire_ramirez223mo ago

Three inches is no joke. Did you have to step down the tool diameter a lot to get that stub length to work, or did you find a good source for them? Chatter on a finish pass is the worst feeling.