Quote Originally Posted by Dodgy Geezer View Post
Thanks very much for taking the time to input!

The end mills are new but I did run with a slow feed speed and a fast RPM. I oiled the surface to try to prevent sticking - but your comment makes a lot of sense. It's a bit dark and cold in the shed at the moment, but I will look at the mill tomorrow, and perhaps try a faster feed and a slower rpm....
What grade of Ali are you using