I've long wanted to try building a chair but I was intimidated by all the angles involved. While I was researching sculpted seats, I came across this build and I thought it was really neat. So I purchased the plans and started modelling the seat in CAD to make a few modifications. I simplified the design to have fewer parts and changed the joinery from screwed butt joints to through tenon joinery with dowels.

Since I had the model in CAD, I went ahead and cut the frame parts on the CNC router out of some 1/2" Baltic birch plywood. All the frame parts fit nicely in less than a quarter sheet of plywood.

Modelling the curvature of the seat was quite interesting and part of why I wanted to work on this project. I wanted to start simple and learn to make a "sculpted" seat which I could use for other projects later on. I also wanted to experiment with bending plywood without a form.

To model the seat, I used the top surfaces of the two stretcher/seat support pieces in the assembly to loft a surface. Then I extended it to what seemed like a good size. Surface-Flatten has recently become one of my favorite features in SolidWorks. I used it to get a flat pattern of the seat shape and laser cut two pieces out of 1/8" plywood.

I made the back the same way, but it's a less interesting shape.

A quick dry assembly showed that the seat was not very comfortable and needed the back to lean a bit more. I also didn't like how the cutouts looked so I removed those.

After cutting the side pieces again, I assembled the frame. Through mortise and tenon joinery is pretty strong and the dowels are not necessary for something like this, but I like the aesthetic.

To bend the seat, I used the assembled frame as a clamping form: I put a layer of glue between the layers and used most of my clamps to hold my glue-up on the frame overnight. I must have been overwhelmed by the clamping process, because I forgot to take pictures but this worked really well and gave me a nicely formed seat.

After sanding everything and rounding over sharp edges, I used a block plane and spokeshave to add rolling bevels to where the seat meets the frame to get as tight of a joint as possible. Finally I glued it all together, once again using lots of clamps:

I was also going through a stained wood phase so I stained the seat parts.

And that finishes it. The last photo shows it next to a regular sized chair for scale. It's a bit small for someone my size, but it works really well for my friend's 5 year old. Overall I'm pretty happy with how this came out. I probably won't build the same chair again, but I'm planning to build similar bent/sculpted seats soon.