On May 7, 6:41*am, "Thomas G. Marshall"
. com wrote:
John Martin said something like:

...[snip]...

I've got one trick of my own. *As I do a lot of metalwork, I've made
up some transfer or spotting screws. *These are somewhat like dowel
spotters. *A large flat head just as thick as the distance between the
hinge leaves when closed, a short shank of the diameter of the hinge
hole, and a short point sticking up past the surface of the hinge.
Soft steel is fine. *Mortise and screw the hinges onto the box bottom,
then open the hinges and place the spotters through the holes. *Close
the hinges down on the spotters, and you'll now have points sticking
up where the screws need to be, so position the box top and tap it
lightly to mark the screw holes.

John, could you post a link to a picture of that thing? *It's obviously
nothing I can make, but I am curious.

No digital camera. Think of it like this, though:

Mortise the box bottom and attach the hinges with screws. Now,
pretend you are going to attach the top with common nails through the
hinges, instead of screws. Put the nails through the hinge leaves,
and fold the leaves over into the closed position, so that the nail
points are sticking up. If the nail heads are the thickness of the
space between the hinge leaves when closed, and the nail shanks are
the diameter of the screw holes, you'll have the nail points right
where the screw holes need to be drilled. If the nails are so short
that just the points stick up through the hinges, you've got it.
Place the box top over the closed hinge, align it, tap gently to get
the points to mark it, and you're done.

Or like this:

You've seen dowel centers used to transfer hole centers from one piece
to another. From the bottom - a cylindrical shank to fit into the
dowel hole, a large flat rim to keep it from pushing too far into the
hole, and a small conical point to mark the hole center on the other
piece. These hinge spotters have those same parts, but the order is
changed. The rim is at the bottom, and is the thickness of the space
between the hinge leaves, to keep them parallel. Next the shank,
which is the diameter of the screw hole and the length of the hinge
thickness. On top is the small conical point.

If you are using cast or machined hinges where the leaves close
tightly against each other, eliminate the rim or make it to fit the
countersink.

John Martin