On to making the headboard frame now.
I double checked the CAD design, which called for a 10 degree lean on the headboard. This was done with the scientific method of lying a 2×12 against the bench and adjusting the lean so it was comfortable while sitting on the floor.
I think I got about 18 degrees with measuring.
I managed to get about 15 degrees out of the 2×8 when I laid the template against the wood. I could have gotten more maybe, but I also wanted the legs to cant backwards, like I had done on my chair.
I used a full-size drawing as a template and cut out two legs. Then I doubled them up in the vise and planed them together to make sure all the faces are uniform.
The headboard is made up of two legs, an upper rail, a mid rail, a lower rail, and a panel. The mid rail has a built-in angle that makes the transition from the vertical against the mattress to a leaning headrest/backrest that incorporates the panel.
Making this involved ripping up a board with a beveled cut and gluing it back together to form the angled shape. This seemed a lot easier than shaping one large piece of wood.
However, this angled rail needs mortises and tenons to suit. I came up with this configuration. I think the span from top to bottom is small enough that splitting should not be an issue.
The tenons were then hand-sawed out to suit and I dry fit the joint.
With the midrail dry fit, I was able to mark off and measure for the upper and lower rails. Then I cut the joinery for them and knocked the lot together.