Hello all. Question when using the little 5mm Barrell Hinges for pen boxes and other little boxes how far from the back edge of the piece do you set these? I know you have to chamfer the back edge but just curioious on where to set them from the back edge. I have some info in one of Doug Stowes books but other than how to use the simple jig for placement on each side there isn't alot of info. Anyone have any instructions on this that would help?