Neil Erickson suggested that I line up the hinges for each door by threading them onto a long rod. That seemed like a good idea, but it took me only thirty seconds of struggle with what felt like a miniature version of a two-year-old who refuses to go in her car seat before I decided that more containment was required. So, as when I learned to put one hand on that two year old’s chest, and buckle with the other, I got smarter.
It’s not much of an invention, but the fixture I came up with provided a constant distance between the hinge centres and the edges of the doors. Then, with one axis of freedom controlled, it was relatively easy to eyeball the other and glue the hinges down. The hardest part was remembering to turn half the doors upside down so the hinges would come out on the right sides!
There are two pieces of brass angle, augmented by slips of .005″ styrene to provide .020″ of clearance between the hinge pins and the edge of the door. Add on the .015″ for the pins and .006″ for the hinge strap itself, and we come out at .041″ – pretty close to the .034″ that scales from the photograph.