Robart sells a drill jig if you want to buy one. Another method is to make your own using a short piece of 1-1/4 to 1-1/2"" diameter wood dowel. Cut a 45 degree "vee" at one end and drill the appripriate sized hole lengthwise through the center. You now have a drill jig that's pretty difficult to set crooked since it fits the hinge line bevel.