Probably usage of what we call a "Hole Saw" Al. Either that or by use of a compass cutter having a tool bit on an arm rotating in a drill press. Either way, you get both the hole and the centre piece, but maybe Peter does it a different way? Hows about it Peter? Jesse in Tennssee > Peter, you mention "trepanning a hole." Would you > enlarge upon that proceedure for the sake of those of > us who are scared to death to try it? > > Al Messer MODEL ENGINEERING DISCUSSION LIST. To UNSUBSCRIBE from this list, send a blank email to, modeleng-request@xxxxxxxxxxxxx with the word "unsubscribe" in the subject line.