Scott,

You may already use this method, but I wanted to share something I learned about using the [link=http://www.houseofpylon.com/Tools/HoleSaw750.aspx]3/4" Hole Saw[/link] to cut holes in wings.

If you press the hole saw down so that the teeth are seated, then turn the saw backwards until you have a nice groove, then possibly work it back and forth, you will get a real nice clean cut.

If you try to start out turning it forwards, it tends to wander and tear up the surface around the hole some.

I recommend practicing on a scrap piece of foam with some balsa glued to it.