The arms for the chair start with two rectangular blanks about 5 inches wide. These blanks needed to be roughly shaped before the outlines of the actual arms can be cut out at the band saw.
The shaping process for the arms involves two steps. The first step utilizes a jig that facilitates cove-cutting a grove diagonally along the length of each arm blank. This cove cut removes stock that will eventually become the area that your arms rest in when sitting in the chair. The second step of shaping the arms will occur when they have been attached to the chair and more stock can be removed and the curves can be faired into the legs. Before doing any cutting, I first marked the outlines of the arms on the blanks so that I could see their eventual orientation and not get confused while performing the following steps.
The jig for the cove-cutting at the table saw is a rectangular box with an angled portion that rides against a fence while transporting the arm blank over the table saw blade. The angled piece allows the blank to travel, top face down, across the blade so that the resulting cove is cut diagonally through the length of the arm blank. These cuts were done in a slow and methodical manner, raising the blade about 1/32″ – 1/16″ for each pass over the blade. The jig was moved across the blade slowly to allow the blade to cut the cove as smoothly as possible and to also allow the significant dust to be cleared. Even with this technique I stopped every few passes and used the shop-vac to clean the dust remaining on the table top. The jig has handles with threaded rod through t-nuts to clamp the blanks in place as well as a handle to help push it through the blade. I also used a Gr-ripper push block for added control and security. The jig flips over and the handle reverses for the alternate arm to be cut with a reverse orientation of the diagonal cove. The first two pictures show the right arm being cut and the last picture shows the left arm.
Once the cove cuts were completed I again traced the outlines of the arms onto the blanks (albeit a carefully due to the now undulating surface of the arms). Then the arms were band sawed to shape and sanded with the oscillating spindle sander to remove the band saw marks along their edges. In the picture you can see the rough shaped arms after cutting and sanding.
The other step that I completed at this time was to glue up stacks to the rockers. These stacks consist of rocker strips and are located at the points where the front and rear legs will contact the rockers. The stacks serve to elevate the chair above the rockers an additional distance as well as to provide material for shaping and fairing curves from the rockers into the legs. This was a bit of a tricky operation as the stacks wanted to squirm away while they were being glued. I again used the same rocker clamping caul to distribute the clamping pressure to the stacks.