In this post we’ll see how to make an impossible dovetail joint. Well, actually we’ll see how to make a curved dovetail joint. My idea is to turn one piece towards the other so both parts fit together. I will make both parts of this dovetail joint in the head of two square section strips. And I have to make a dovetail jig to route each part. When I fit both parts together they will look almost like the impossible dovetail joint. Almost like it.
As I mentioned before, I will route this joint in the head of two 6.5cm square section strips. And I have to make a kind of dovetail jig to route the curved tails and the curved pins.
Then, I have to make a kind of box that fits perfectly around the workpieces. And I put a pivot pin in one corner of that box.
Now I have a board on the router table. And I made a groove in that board so I can move the board to have the dovetail router bit inside the board.
I stab the pivot pin near the groove, I move the board to the first position to route the first curve, and I clamp the board.
And while I press both, the box and the workpiece against the board, I turn the box with the workpiece to route the first curve.
Then I move the dovetail jig board to the next position. And I route the second curve.
Like this I have the pins in the head of the first strip.
Now I use the pins to set the dovetail jig to route the tails. First I route the tails some wider than needed. And then I adjust them, routing just a little bit each time, until the dovetail joint fits.
But I have to use a hand saw to cut some parts (because I cannot route that corner near the pivot pin). And I have to make some sanding work until the pins and the tails are smooth. But I also had to put some wax in the pins and in the tails, so the dovetail joint fits smoothly.
It takes some time to adjust this impossible dovetail joint. And despite I make the dovetail jig, it is almost impossible to make a perfect joint. But anyway I think I made a nice and interesting woodworking joint.
You can also watch how to make a half blind dovetail joint using the router table.