Introduction: Plyboo CNC Armchair
The Plyboo CNC Armchair is an exercise in cnc fabricated furniture that looks to move away from the visual language of CNC mark making and geometry, and towards the production of an object that is not a reflection of the tool on which it was made.
Drawing inspiration from traditional armchair design, the ergonomics and aesthetics of the chair are deliberately classical. Another goal of the project was to eschew the rectilinear aesthetics of most cnc 'flat-pack' furniture in an attempt to create a more nuanced object.
Step 1: Design
In my previous experiments with the shopbot, the mark making of the tool and the radius of the router bit were necessary artifacts of the types of joints that were created. Often these joints are referred to as 'dogbones' because the radius of the tool extends beyond the useful envelope of the opening in order to create square corners.
In the case of this chair design, the goal was to hide the mark-making of the tool behind material, using dado cuts and slots. Furthermore, the goal of the project was to attempt to break the normative aesthetic of shopbot projects that only allow objects to be joined at 90 degree angles. The arms / back were an experiment in attempting to get more nuanced geometries out of planar parts.
The aesthetic of the chair is intentionally traditional. The question became whether or not these new digital CNC tools could be used to create objects that could still be part of a classic aesthetic language.
Step 2: Shopbot Cutting
The process of cutting the parts for this chair were fairly basic. The design was not particularly well optimized to nest on the sheet, which was a deficiency that I attempted to remedy in later projects. In order to attempt to save some materials, the more cumbersome elements of the design were split in two and joined with a number of experimental joints. The arms were joined with a 'puzzle' joint. The stretchers were joined with a cross joint. These joints were a fun twist on the otherwise simple cutting and fabrication process.
Step 3: Assembly Setup
The parts of the table are taken off of the shopbot and laid out. The joints are glued and clamped before the rest of the assembly could take place. Once all the pieces have been combined and attached, the chair is ready to be assembled.
Step 4: Final Assembly
Plyboo is an interesting material in that it is very dense and hard, which leads to a solid construction and surface condition. This positive attribute has negative repercussions when it comes to press fitting joints. Unlike traditional plywood that has more ability to bend and compress, plyboo prefers to split and crack when pushed into friction joints. The fit of these parts were such that they worked well in plywood, but in plyboo they were simply too tight. I decided to open up the slots and holes a bit wider, and then glue and clamp the connections, as opposed to risking cracking and splitting that would likely occur if a hammered joint were attempted.
With the absolutely correct tolerance I am sure you could get a snug, secure, viable press-fit joint, but as a prototype I did not want to take the risk, and since there was not another iteration to test fitage with adjusted dimensions, this is how the chair came together.
The chair is sturdy, solid, and after using it at my desk for over a month now, I can say it is also quite comfortable.
Thanks for taking a look!