Proctologically Violated©® wrote:
Awl--

90 deg 3-flute c-sink, .225" deep into 6061 alum that is already
substantially c-drilled, #5, about .250 deep.

Problem: chatter marks, altho not audible, and not really bad looking--not
a bad effect, really.
Just would like a really smooth finish on occasion, which I achieved once,
but have not been able to replicate.

I have found a slow rpm much "friendlier" than faster rpms, ie, less than
300, vs. over 750.
True?
Push w/ more force? Less? some combo w/ different rpm? "Finish cut"?
Diff. style c-sink? Oils?

TIA.
--
Mr. P.V.'d
formerly Droll Troll


Like Dev says go slow. Don't tease the feed. Some times when chatter
starts its self perpetuating so try not to ever let it get started. The
chatterless style are the ones that chatter the most. I prefer the style
with the 1 hole going thru at an angle. They might be called true cut
types. Snug your spindle lock to take up any spindle clearance but still
allow spindle feed.