For me, making a chair starts at the sawmill (photo A). The local mill here lets me select the logs I want and then saws them to my specifications: mostly 8/4 for the legs, 6/4 for the front rungs, and 4/4 for the side and back rungs. (See figure 1.) Although the figure and lead photo show a rocker, which is my signature piece, I was making more ordinary chairs the day we photographed the process, so I've focused on that type of chair.
Having whole logs sawn at the mill also allows me to maintain uniform color and grain in a set of chairs by using boards sawn from the same tree. I stack the lumber carefully in a breezy location under metal roofing. To minimize warp, I place dry stickers of uniform thickness between the layers, spacing them 12 to 20" apart and directly above those in the layer below.
After a year or so, I move the lumber into an open shed and stack it without stickers until I'm ready to use it. The wood's moisture content at this point is about 14 to 20%, the optimum for green woodworking. Since my turning stock is sawn instead of rived, I pick the straightest-grained logs I can find for strength. I've learned to identify figured wood in an unmilled log, so I keep an eye out for curly maple and quilted cherry.
I rip the air-dried 8/4 boards into 2x2" material for the front and back legs. I joint one edge, then rip the 2"-square stock into strips to be cut to length later. Before turning the wood, I remove the corners on the square stock, which lets me keep the tool rest on the lathe in one position. Normally, you have to move the tool rest as the diameter changes, but starting with the octagonal shape eliminates this step.
To rough out the rungs, I use a dowel machine (circa 1920s) that I salvaged from a broom factory (photo B). I then sand the dowels on a stationary drum sander, using a fixture I devised from skateboard wheels. The wheels are mounted slightly above the drum sander; they hold the dowel in place as it rotates on the sander (photo C). I wear heavy gloves for this operation, as the dowel spins quite fast.