I've gotten to an exciting point on the chairs.
I left off with the legs half finished and some parts rough cut. I cleaned up the other side of the legs. They fit together nicely. I placed the legs in pairs trying to keep all the legs from the same board together so grain and color would match closely. I positioned the unfavorable grain towards the inside.
I wanted to start with the backs of the chair and work my way forward. I took the measurement that would space the legs apart and cut the 3 rear pieces, the headrest, the bottom back rest, and the bottom rail. I then milled the material strait and square and cut to length using a miter gauge. After using a miter gauge I find myself unable to go back to the mitersaw for critical work.
With the parts cut I was able to start laying out joinery. This will all be floating tenons with the widths dependent on how much space I have available. I marked out 2 legs with the tops and bottoms of the boards and then the center of the joinery.
I used this to cut the joinery on the first char (chair A). I then did a dry assembly so i could determine the length of the back rest.
I have deviated slightly from my original plans and have added a bottom back rest part. This allows the joinery on the back rest to be strait and square and leaves me free from trying to deal with a nasty angle that may change from chair to chair.
Then i grabbed a piece of 6/4 material and cut it in half thickness wise. I was able to plane it out to around 16mm thick. It's a bit thick but I like the stability and it allows substantial joinery. I used a template to mark the rough shape and clean up on the router table.
I used the painters tape and superglue trick here as I didn't think the time to make 2 complicated sleds was worth it.
I then took the back rest cut to shape and length and marked out some floating tenon joinery and tested it out. Everything worked out great. So i took the 2 legs and used them as a story stick to mark each leg for joinery locations and length. I first cut to length.
All 12 legs then had their joinery mortises cut.
Following that I took the back rest parts and cut the matching joinery in them.
All the mortises are 8mm thick.
The momeny I was waiting for was to do a dry assembly of the one back rest I had finished. I'd been waiting years to finally see my idea in the physical form instead of just an idea on paper.
I have to say that it was a long wait and I think I'm going to love these chairs when they are done.My goal is to have 3 chairs sweep right like the one above and to have 3 chairs sweep left. This way 2 chairs on the sides of the table will either sweep away or towards each other. This bit was the other aspect that using a flat back rest made easier. If i wanted this to work out this way I'd have had to make 2 complicated routing jigs to accomplish my goal.
I have a lot more work left. I still have a lot of back rests to cut out. Then each part needs to be cleaned up sanded rounded over and completely ready before glue up. After it's glued up planing surfaces will be a lot harder to accomplish.