Old timer at a shop in Detroit showed me why my inserts were chattering

I was running a job on a Haas VF-2 last month at a small shop near Detroit. An old guy who's been running machines since the 80s walks over and watches me for a minute. He points at my tool and says 'your stickout is wrong, kid, that's why you're getting that noise.' I had about 3.5 inches hanging out for a 1/2 inch end mill. He told me to drop it to 1.5 inches max. I did it and the chatter went away almost instantly. I always thought the extra reach would help with clearance but it was just killing my surface finish. Has anyone else had an old timer call them out on something obvious that you just never thought about?

2 comments

2 Comments

uma68512d ago

Wait is 3.5 inches of stickout on a half-inch end mill really that bad for clearance though? I mean yeah the old timer was right about chatter but sometimes you need that extra reach to get around a deep feature without crashing the holder. Just gotta balance it against rigidity, that's all.

ray18911d ago

Aw man, 3.5 inches on a 1/2 inch end mill is pretty extreme. You're basically asking for chatter at that point, especially if you're pushing it hard. I mean yeah you can get away with it in some materials (like aluminum with light passes) but it's a gamble every time.