Quote Originally Posted by njhussey View Post
(see above pic, I use masking tape...
I saw the tape and suggested clamping the edges because you were taping, not clamping the work.
Masking tape is specifically designed to be removable and doesn't offer much hold down capability in the face of a persistent force such as the lift from spiral flute milling or routing.
Swapping to a good commercial grade of gaffer tape and ensuring the tape runs down the vertical side of the work and contacts the spoil board at the edge of the work will give you a big improvement in hold,

- Nick