Ok, so I'm making some headway here! I'm onto the fifth and last piece of my desk side...the top. In most cases, this piece wouldn't be particularly difficult, but the branched joint obviously complicates the back joinery. A reminder picture:
The intersection at the top left...between wishbone and knotty piece of alder...will require some angled joinery, and angled in such a way as to bring it in parallel with the floor. After some trial and error with the rise/run of a wedge, I got the right (as in correct, not 90) angle and started making the joint. A traditional mortise and tenon wouldn't work particularly well here...so new vocab: I used a bridal joint! No, it's not super fancy...it's often used in frame construction, but mine is angled so it's cooler.
With the wedge, I brought the branched piece down to length.
Next, using a vertical tenoning jig that Noah and I made over the course of a few days (yeah, that's teak plywood...only the finest for our jigs), I made consecutive cuts through the bottom making space in the center for an eventual tenon. Wedge is used again, as the cut/inner surface of the joint should be in a similarly angled plane as the end.
So that's one half of the bridal joint! The other half, the enveloping top stretcher is easier, but I forgot to take pictures of its making. Basically, I used the wedge on the table saw, blade raised to just the right height. With a series of passes over the saw, I had a tenon that fit snugly into the bridal mortise. Better than a description, I did take pictures of the results:
After a traditional M&T on the front end, I had a completed frame! Two frames actually.
Up next: continuing with more mortise and tenons, this time width-wise stretchers and six in total. Oh...and a special treat, or just an accidental reveal...I spy a soon to be completed weekend work project on my bench...and some shoes. Play with your kids, it's a great game.