Beginning the Assembly
First, I assembled the ends of the case, then I drilled and chopped the mortises to accept the long front and back assemblies. By doing it this way, I eliminated some of the tearout you could get from drilling and chopping through existing holes in the posts.
After all this horsing around, I assembled the long sides, added the floor and brought all the assemblies together, using customary and prodigious amounts of glue. After getting it all clamped up real good, I turned on the air conditioner to hopefully lessen the effects of the steamy summer humidity we were experiencing here in “tropical” Minnesota. I let the project sit overnight, to give the glue plenty of time to set up and cure.
The next morning, I removed the clamps, which revealed a sturdy little piece of furniture. I added a ledge of two 1″ x 3/4″ x 1-3⁄8″ mesquite cleats to support the box lid, which is simply a straight, thick mesquite board, planed and drawknifed at the edges.
Routing Sliding Dovetails in the Top
With the carcass completed, it was time to make the top. I set aside two planks early on for this component. After surfacing a straight, square mating edge on each, I chose two more boards to serve as the top support rails. These sit within the saddles cut into the legs. They have a pivot point at the back, drilled through and pinned to the legs with a couple of simple whittled pegs.
I attached the top support boards to the top planks, 2-1⁄2″ shy of the leading and trailing edges of the top, using a simple sliding dovetail arrangement. After laying out my system on the underside of the top, I clamped the two planks together nice and flat before adding a straight board to use as a fence to guide my plunge router. Then I took three deepening passes with a 1/2″ straight bit until I reached a depth of 5/8″. I switched to a dovetail bit to shape both sides of the housings, taking one pass for each cheek. To cut the mating dovetails into the top edges of the top supports, I chucked the same dovetail bit into a router table and made a few passes on scrap wood to dial in the fit. Once everything was set, I routed the two supports.
Here’s how I assembled the top: I fitted the rails onto one plank before sliding the other plank into place. I glued only the edge joint between the top boards. (It should slide on the dovetailed supports as needed to allow for wood movement.) Once the glue cured, I scraped off the excess and took my drawknife to the edges. A light scuff sanding with 220-grit cleaned up the surfaces, followed by a topcoat of shellac.