I rough cut the end miter on the head rest with jig saw, and then I flush trimmed with a clamp-down straight edge. I am not able to find an exact angle on the head rest miter due to the shaping and steam bent spring-in. My plan is to make the miter on the head rest as accurate as possible and test and cut out the front legs miter joint to compensate the 90 degree relationship. In addition, the bottom rail has to land within the edge surface of the front legs, and the both front legs needed to tilt at reasonable angle. The entire process was slow and tedious, but I was able to finally figure it out. Next, I layout the joinery and cut with Felstool domino machine.
I used horizontal mortiser to cut the mortise on the bottom rail. Since the rail is a curved part, I decided to drill holes at different height to accomplish the mortise vertically. Similarly, same technique was applied on the front leg mortises; they were drilled on the drill press and chiseled smooth by hand. Moreover, the chair seat frame have been sent out for the upholstery, and the seat panel is glued to bottom rail to not only support the cushion, also correct the spring-in happened on the bottom rail. The back legs are glued and trapped into the seat panel in order to create a concrete solid structure to support the chair.
Before I start the final glue up, I managed to cut all legs to level and hand shape many parts to rough form, because these tasks will be too difficult to once the chair is glued together. I separate the glue up into 3 stages, the first stage is to glue up back legs and bottom rail to seat panel, and the under seat rail is attached by through wedged dowels. Further, the second stage is to glue all bottom of spindles with G2 epoxy to bottom rail; the third stage of the final glue up is to glue spindles to head rest with epoxy and rest of joints with Titebond at the same time. After the epoxy is dry, all spindles are locked by 1/8’’ pin as shown in image. Thanks to my classmate’s help, my final glue went well, and now is time to start final shaping, refining and sanding.