The construction of the sella curulis, a medieval folding chair, is going steady, but slowly. I am currently carving the chairs legs, which is quite a lot of work. This also includes carving test pieces, to check if the design is appropriate and to make myself more comfortable with the carving process of each specific part. The photographs below show the progress and I will give my comments to each step.
After the making the legs of the sella curulis, described in a previous post, I first made the side rails which connect the two sets of X-legs. I have three side rails planned for the chair: two flat ones, that come on top of the chair and will hold the leather seat, and one at the cross-section. The latter one is turned in a medieval style also found with turned chairs. The side rails all end in tenons. The mortises for the flat rails were then made into the X-legs, using a machine drill at a set depth for the rough work and a chisel to clear out the mortise and make it square. The next three photos will give an idea of the final chair.
Frontal view of the sella curulis
Side view of the sella curulis
Top of the sella curulis
The next step consisted of rounding off the edges of the legs. A draw-knife and a scraper were used for this step. The leg was set in a vice on the work bench and first worked with the draw-knife - taking care of the direction of the grain of the wood, and then the edges were smoothed with the scraper.
After the rounding of the edges, two rings were carved to mark the "head" and the "feet" from the rest of the leg of the chair. The photo below shows the rings next to the mortise hole of the top rail.
The following step consisted of carving the central roundel. I wanted a spiral pattern which is also commonly found on medieval chests. A few examples of such chests are shown below. For carving I had much use of a small book (in German) on chip-carving entitled: Das Kerbschnitzen - ein Lehrgang fur Anfanger und Fortgeschrittene by Christian Rubi (1959, Verlag Hans Huber, Bern, Switzerland). According to this book you need only one tool: a chip-carving knife. And of course a calliper/divider is useful for laying out the pattern. A typical saying in this book goes: "A carving does not fail due to lack of talent, or the wood used, but of lack of a strong will to guide the knife on the drawn pattern".
Two 12th/13th century chests from the Musee the Valere, Sion , Switzerland made from walnut. These chests have elaborate chip-carved roundels, but also the arcades in the central panel and legs bear chip-carved patterns. Sizes of the chest are 103 x 201 x 62 cm and 100 x 190 x 50 cm, respectively. B/W photo from Mobel Europas - Franz Windisch-Graetz; color photo form Musee de Valere.
This 13th century oak hutch from a church in Hampshire, United Kingdom, with three different chip-carved roundels.
The chest now resides in the Victoria and Albert Museum, London, UK. Sizes of the chest are 50.6 x 109 x 48.2 cm. Photo copyright V&A Museum.
I did not trust my strong will to guide the knife that much, so I made a test piece of the spiral roundel first. It was easier than I thought, but I was glad I made the test piece first. The roundel on the actual leg of the chair was better than the test. After the spiral roundel, I added several smaller roundels with a different "star" pattern (like left roundel on the Victoria and Albert Museum hutch) on the leg. Each star roundel was specifically fitted to the width of the leg at that point. Tricky point here is that you must start with the incisions that sever the fibres, and after that those that follow the fibre. Else, some pieces will break off - luckily they did on the test piece.
The test piece of the spiral roundel.
The actual central roundel with the spiral pattern in progress.
One of the star-shaped small roundels
With the roundels all complete, a zigzag pattern will be carved in the space between the roundels. A zigzag pattern is ideal as it can easily follow the curve of the leg. This is the stage I am now working at. The last two photos show some of the patterns carved on the leg.