Quote Originally Posted by fotch View Post
I would use my Sherline Mill, drilling a small center whole so i could then rotate the board with geared table (forget what it is called) and cutting the hole as it rotates.
Securing the center of the lensboard isn't sufficient. You need to secure the outside edges too, so that the board doesn't move as the cutter goes through it. Put a piece of waste underneath and tighten everything down.

Charley