Good progress today. Got the case assembled. Before I assembled the case I had a little more work to do on the middle shelf. I wanted a table top edge on it. I’ve got a 7/8” table thumbnail edge bit that I like. Not an expensive bit, less than $20 I think from Super Carbide Tools
This bit is about 2-1/2” tip to tip so the router needs to be slowed down. Consult the manual for your router if it is a variable speed. Or the manual for the external speed controller you should otherwise be using. Don’t spin this thing at 20,000 RPM
The resulting edge looks like this:
The hardcore Neanderthal would or course be using handplanes and molding planes for this. I don’t have any such tools but a router and router table does a good job too. :)
To make the edge a little bit more refined, I’ll chamfer the bottom just a little bit. Here I could use a block plane but there is a little bit of interference from the inset sides of the table so it is just easier to use a small 45deg chamfering bit in the router.
And here is the finished result of the bottom edge chamfer as seen on my test piece.
Now it is time to start making the dados and grooves in the sides of the case. I picked up a 1/2” diameter pattern bit with a 1” cutting length. Before using any router bit that has a bearing, check the set screw. Especially new bits. I’ve found several that had loose set screws. On ones with the screw into the end of the shaft, it would self tighten when spun up. But ones with the set screw into the side of the shaft, the bearing could drift. This is bad. My dado jig is pretty simple, two 3/4” thick lengths of MDF with a cleat at one
end. The cleat catches the work piece and the straight edges of the MDF will define the dado width. Pinch the shelf piece between the two jig sides and you get a nice snug dado. I made the MDF pieces long enough to span both halves of the case clamped edge-to-edge.
First I install the bit, then I zero the bit depth in my plunge base.
And finally, I use a 1/4” bit to set the plunge depth on the stop and turret. Some people will tell you twist drills aren’t accurate enough for this but I checked the shanks on the drills in this set and they were within 0.005”. Close enough…
Run down one edge, then back on the other. Pay attention to the bit rotation and work left to right pushing the router into the jig edge. Done! Move the jigs down and do the dado for the center shelf. Align one jig edge with the tops of the extensions on the sides. The shelf rests on them as it exits the dado.
Next I use my long straight cutting edge jig and line it up on the router side to cut the rabbets down the side pieces for the back boards. The rabbet does NOT go below the bottom board so the dado acts as a stop for the rabbet.
I can now sand the sides and get ready for a dry fit. The shelves were already finish sanded before using them to size their dados. A side note on the dados, I didn’t make them so tight the shelves were a press-fit. Since this is lumber and not plywood, it will move a bit. The dados are 2 playing card widths extra wide. This seems to be around 0.02” extra. If the shelves were plywood, I’d make the dados a press-fit.
Dry fit time!
Now get a few more clamps ready and do the glue up. The joints will get re-enforced with some cut nails (yes nails). This is a Shaker piece and nails are OK, especially since I’m using cut nails. Just make sure to orient them correctly so they work like the wedge they are designed to be. And make the pilot hole (scant hole in the ‘lingo) about the same size as the midsection of the nail.
Break time. :)
-- Don't sweat the petty things and don't pet the sweaty things.