Like most things it takes much longer to explain a process than it does to complete. Still, there are a lot of steps involved, and while you can sometimes change to order chances are there are no shortcuts, especially when precision is the final goal. Well enough philosophy, how ‘bout we just do woodworking. At this point the jig is maybe a half hour from being functional.
Here I trimmed one side of each template to about 1 3/4” from the centerline of the mortise. You may wish to also trim the other side, but for this setup, since the knuckle of the hinges will rise above the surface you need the room so the router does not bump into them (see step one of this blog). Of course you can get around this by simply mortising the hinges into the templates. This requires a little more work and requires a precise alignment so the mortises line up. It seems to be just as easy to leave the template’s wide and apply the hinges as you’ll see below.
Next we raise the blade to cut a little higher than the centerline of the mortise to create a channel through which we can attach a fence to register the mortise against the back of the box.
You only need to make these cuts on the wide (top mortise). Remember, we cut the top (the wide and shallow) mortise first, then the narrow, deep bottom mortise.
Then head over to the router table and cut some dados, grooves, channels, whatever, deep enough so the head of the screws holding the fence do not interfere with the router.
Now comes the payoff pitch. The two templates are self registering. Since they are the same height and width, you simply pair them up and attach hinges to the end. The only thing you have to watch for is that the side you just cut on the router is on the inside.
Next time we’ll get a very precise alignment of the fence, do some test cuts, and finish the series. Hope this helps.
-- tim hill www.newcalshop.com