Guessing: It looks like the end of the cutter has made full contact, causing chatter. Not enough relief, the endmill has slipped in a collet, or there's a lot of flex in the mill. The full circle here is saying something:
12-21-2015, 11:12 AM (This post was last modified: 12-21-2015, 11:13 AM by Dr Stan.)
I agree with Sunset. A couple of fixes to consider are 1) sandblast prior to HT and 2) skim with a fly cutter or HS end mill. Sandblasting is commonly used in mold making as the first step to polish cavities.
(12-21-2015, 11:03 AM)Sunset Machine Wrote: Guessing: It looks like the end of the cutter has made full contact, causing chatter. Not enough relief, the endmill has slipped in a collet, or there's a lot of flex in the mill. The full circle here is saying something:
Yes, the inserts basically sit flat against the work. I tried drilling through a thin piece of steel when I first got the cutter and stopped because of all the racket it made. http://www.metalworkingfun.com/thread-28...l#pid48450
The inserts definitely sit at different heights and the outer one does most all the cutting as far as I can tell. I'm thinking it's probably a combination of the mill slipping in the collet, and the Chinese cast iron made from noodles in my mill.
If a skim cut with HSS doesn't smooth things over, the next stop will be the blast cabinet.
I am just trying to get a better understanding of electronics ,the kits are cheap ,fun to build and even more fun to trouble shoot when they don't work and I dont care it I fry one as I would just build another .