Wrap Chair
Wrap Chair
Overview
The Wrap Chair is a study of material capabilities, versatilities, as well as a deep dive into the powers of advanced digital fabrications. The chair was designed for a set of two to be fabricated using a single sheet of 48”x 96” plywood and no additional hardware for assembly.
Design Process
The chair was originally designed for the #RocklerPlywoodChallenge. The rules for the challenge were simple. I had one month to design and build a product using one sheet of 48”x96” plywood with no additional materials. Any tools could be used for fabrication. Because I had just recently finished a class based around Advanced Fabrication for Production, I decided to create a chair that was intended to only be CNC'ed and wouldn't need any additional machining or hand fabrication to finish the product.
Ideation + Prototyping
Initial ideations started with a study into midcentury modern furniture as well as a study of profiles that would become the future chair. Several sketches were selected as potential final designs and explored in further detail.
Ultimately, two designs were selected, built out in AutoDeskFusion 360, and rendered. All the dimensions were based on current furniture standard and heights. Both models used a combination of mortise and tenon joints as well as tee halving joints to assure that the chair was assembled with minimal to no hardware. Joint seems were also limited to as few as possible.
At this point it was important to note that one of the initial design goals was simply not feasible from a fabrication and financial stand point. In order to give the chair a reasonable thickness and sturdiness, the chair would have to undergo some post product work. Even though this is contrary to one of the initial design goals mentioned above, having the chair be a thickness of double the plywood sheet provided to be a sturdier, and overall better design. Post product work was limited to gluing two identical halves together. The other alternative was to purchase a sheet of plywood that was 1.5” thick. However, that material was unavailable given the cost and timeline.
To get a better understanding of physical proportions, each of the chairs was laser cut to ¼ the scale of the actual product. This is always a process I use when prototyping large-scale products. While the actual renderings help me to understand what the product would be like, I often find that building out and holding the physical model introduces a perspective that is often really hard to grasp through a computer screen.
Before I built the smaller scale prototype, I had been leaning towards the more angular chair with the pink background. However once I held both models, I realized that the more rounded chair with the green background was not only much more interesting in terms of actual manufacturing techniques, but was also a much more aesthetically pleasing chair and was ultimately selected as the final design.
Fabrication
Once the model was fully designed in AutoDesk Fusion 360 and the profiles were all arranged onto a single sheet of plywood, the files were exported into the AlphaCam, the CAM CAD software that interfaces with the 3 axis CNC router.
The most critical dimension of the whole process depended on the thickness of the material. Because the final chair used a combination of mortise and tenon joints as well as tee halving joints the depths of the cuts were not pre-set but determined by the half thickness of the material. This process, while fine for a custom designed should be reviewed for the next iteration of the chair to expand potentials for larger scale fabrication.
Using the 3 axis CNC router, the entire chair took less than 20 minutes to cut. The glue up happened in two steps with the first one comprising of gluing each of the halves together to double the thickness of the chair to add stability. The second glue up consisted of the final assembly with additional dowels being added to the joints to secure the chair.
Final Design + Next Steps
The following gallery features the final wrap chair designs that were submitted to the #RocklerPlywoodChallenge sponsored by the Modern Makers Podcast and Rockler, butwas also featured as one of the Top 20 Featured Designs video linked here.
This chair is currently being redesigned to include further woodworking techniques. The back wrapbrace will be created from several sheets of ⅛ plywood all laminated and bent together. This will create the appearances of a continuous plywood grain that remains in line with the grain of the legs. The seat will also be made from strips of plywood laminated together in the same direction.
