I'm cutting contour profiles in a thin walled (.1") press formed soft aluminum shell, I think it's 6061-T0 or something close to that (I'm trying to verify now).
I'm using a .5" 2flt high helix HSS ball mill and am having chatter problems. I'm currently running at 16ipm (.001ipt) and 8,000 rpm (1000 sfm), .05 depth. I've cut the chatter down somewhat but it's still there and reducing the feed further doesn't seem to help much. The part already takes twice as long as I’d like so I need to avoid slowing it further.
I've tried a variety of feeds and speeds and depths and the above seems to be the best combination. Surface finish isn’t really an issue but I need the tool to last.
I have the part clamped in a vise using an aluminum insert inside the base of the part do it doesn't crush. I tried running a strap across the top as well but it didn't seem to help much.
Does anyone have any suggestions on how I further lessen the chatter and maybe run faster? Are there any special tools made for this type of job? TIA.