Barrel hinges like these are a great concealed hinge for use on small wood projects like keepsake or jewelry boxes. But if you've ever tried to itall one, you know that precise positioning is frustratingly difficult, but critical to get right for alignment. Customizer Note: Thingivee recently broke the Customizer app by making the viewport too small. Until they fix it, use the direct link itead. This customizable guide can be used to get coistent perfect alignment with a hand drill on both sides of the workpiece and its lid. Hold it securely agait the outside corner of your workpiece, and use the hole as a guide for your drill bit. Just flip it over for the opposite side. The STL I've included works well for me with a 10mm hinge and a 13/32 inch drill bit (which is 10.32mm, giving just enough wiggle room to easily iert the hinge). But you may want to customize it to control how close the hinge will be to the side and back edges of the workpiece. Please let me know if you try this and find it useful, or have any suggestio for improvement!