My graduate furniture design course was a great way to acclimatize myself to graduate studies. During undergrad, I had taken another furniture design course, taught by the same instructor, so this class was an obvious choice for me to explore the differences between undergraduate and graduate coursework. While the class I took in my sophomore year was engaging and constructive, it was very guided, and intended to teach fundamentals. The graduate level counterpart was much more open ended, and my (much smaller) class was able to spend more time exploring our designs with our professor, and creating iterative prototypes to see how our pieces translated into the physical world.
The first project we worked on was a family of pieces created from reclaimed materials. The class partnered with Groovystuff, a manufacturer based in Thailand and India, who provided us with a box of material samples, ranging from 55-gallon drums, to sticks and planks, to wooden wagon wheels. We were to design at least two pieces, primarily made from the materials provided, and design them such that they could be fabricated by workers in their appropriate countries of origin. My favorite of the two pieces I designed, the Together Bench, utilized teak planks and sections of a steel drum, cut into strips and clamped together into a leaf spring. The leaf springs cushioned the seat, but had the secondary function of making users aware of the movements of their neighbor, or making a single user conscious of a void to their side. My class, along with several others throughout the nation, submitted their pieces to be exhibited at Groovystuff's booth at High Point Market, and I was honored to find out that my Together collection won the Best in Show award, voted on by practitioners who visited the Groovystuff booth.
Our next project, for me at least, began with cardboard. We were to design a piece which could be fabricated with a CNC router out of a single 4'x8' sheet of plywood, and assembled without the use of any other hardware. Admittedly, I was somewhat influenced by my history in the Department, and my experience building full-scale furniture for a local preschool out of cardboard in my undergraduate career. The main method of construction was the creation of an interlocking grid, which we later skinned with the least blemished sheets of cardboard we could find (we scavenged most of our building materials from local dumpsters.) We finished any exposed edges with watercolor tape, and that was that. While I was happy with my final product, I hated the act of concealing the structural grid. As I built it, meticulously slicing 3/16" slots into my cardboard struts, I began to appreciate the beauty of the grid, and the simple elegance of the strength created by multiple fragile components from merely intersecting them at right angles. When I was finally tasked with creating a hardware-free piece out of plywood, I knew I wanted to employ a similar process.
I decided early on that I wanted to explore complex curves in whatever piece I ended up making. When looking at previous chairs, one consistent feature I found was a fairly uncomfortable flat seat, and I hypothesized that a curved one would respond better to the human form. I was also curious about the creation of curved forms from what was essentially a flat medium, sheets of plywood. I decided to create a low lounge chair, and after sketching out rough ideas for the form, I moved into CAD. I was hesitant to move into CAD so early in the process, but I figured that modeling the exact dimensions of multiple intersecting curves was a task better suited to precise drafting, even if it did mean working somewhat slower. Plus, I didn't want to invest too much time in sketching, only to end up with a design that would fail at some point in the drafting process. My first step was to model the general form I wanted, using basic solids and Boolean operations. After I had a form I liked, I intersected it with a grid of 3/4" thick planes, representing the Z-dimension of the material from which the product would ultimately be cut, allowing me to visualize the grid structure of the piece. Up through this step, I was preforming these steps in parallel on several different starting forms, to see if any problems would arise due to slight variations in particular dimensions. The model pictured ended up being a little too close to the ground at the lowest point in the seat, and I wouldn't have been comfortable cutting into such a narrow piece of wood to create the required intersection.
After moving to a slightly higher seat, I rotated each slice and laid them out on 4'x4' squares, representing the material I had to work with. This was where I encountered my first major problem. Because I had intersected the general form with thick planes, each side of each slice was slightly different, owing to my decision to employ compound curves. I used the FLATSHOT command to create 2D splines from my 3D slices, and then did a fair amount of cleanup, sticking to the larger of the two outlines I had for each shape, for the sake of consistency. Drawing in the intersections was another time consuming step, but once I figured out a reasonably efficient way to do it, it was borderline meditative. I cut a process model on our laser cutter, and it went together easily. A little too easily for me. I had satisfied the letter of my self-imposed constraints, to explore compound curves, but really I was still working on a flat plane, with vertical intersections. I could do better.
I started again from scratch, and employed a similar process. I modeled a new form, a 2" thick sphere, sliced by a few different planes. I again sliced the 3D solid, but this time I used 2D planes, rather than thick planes with a dimension, so that I would have a single outline for each slice. I sliced the solid every 15 degrees, and then again, this time with the planes rotated 90 degrees around the Z axis, but still emanating from the center point of the original sphere shape. After running the INTERFERE command, I was left with a new structural grid, one that I was much more excited about.
I ran the INTERFERE command again, this time selecting the two sets of slices, resulting in the creation of a line representing each intersection of two planes. From here, I had to rotate each slice and it's corresponding intersection lines back onto the XY plane, then halve the length of each intersection line. I did this by dragging the appropriate grip to the midpoint of the line, but looking back, it may have been quicker to simply offset the inner curve of each piece by 1", and use the new line to trim the intersection lines. After the intersection lines were all halved, I offset them by 3/8" on both sides, connected those lines, and trimmed up the shapes so I had a single 2D polyline for each section of the chair. I also explored several options for a base, before settling on a set of rings, one solid and one segmented, separated by an array of legs.
Better, right? At the top left of the frame, you can see an ottoman, originally intended to accompany the chair, but but it ended up becoming very dense, and was plagued by stability issues as a result of its weight, a problem which would have only been worse when cut at full scale. Instead, I created a small side table, at a height appropriate for the chair. The side table was designed as an amuse-bouche for the chair's construction, showcasing the same joinery techniques in a simplified manner. It was assembled easily enough, but the chair presented some problems. I had feared that the thickness of the pieces would interfere with their assembly since each intersection was slightly out of alignment until the two pieces fully came together. I broke more than one masonite model trying to assemble them, but after examining the wear patterns created by forcing the pieces together, I was pretty confident I had a plan that would work.
After all my models and revisions, I was ready to cut my piece at full-scale. I laid out the slices on two 4'x4' squares, and double checked that every outline was a single closed polyline, to avoid issues when importing the drawing to VCarve, our shop's chosen CNC software. Once in VCarve, I added in dogbone fillets to all inside corners, necessary for making square intersections, since the router bit's 1/4" diameter makes perfect inside corners impossible, and a key parameter of the project was to minimize the amount of handwork required after CNC machining. I assigned a tool path to each closed polyline, telling the ShopBot to cut on either the inside or outside of the line, ran a simulation, loaded the plywood onto the machine's bed, and pressed go.
The cut ultimately took about 20 minutes, and when it was done, I cut the tabs holding in the pieces with a chisel, and sanded down any remaining unevenness along the edges of the pieces. After a brief intermission (Thanksgiving break,) I finally began to address the problem of assembling the chair. To get each intersection to fit in the 1/6th scale model, I had been slightly bending each piece to make all of the slots line up. I realized that by removing a small amount of material around each slot, I could greatly reduce the amount of bending required, giving me a fighting chance at making this work. I chose to rout the edges of each piece with a 3/8" roundover bit, ultimately resulting in a half-round profile. I used a hand router, with the pieces mounted in a vise, but using a router table would have eased the process significantly (we couldn't find an appropriately sized collet for the roundover bit for our router table.) This "dehorning" of the pieces gave me just enough clearance when inserting them, allowing the chair to be assembled in less time than the scale model.
After initial assembly, I took the piece apart again, sanded the faces of the pieces to 320 grit, and the edges to 600 followed by 000 steel wool. I once again assembled the piece, and ordered a glass top for the side table from a local glass company. I transported the chair to the gallery of the Johnston building later that week, and after some hasty carving of the side table to get the glass to fit, installed my chair in the gallery for all to judge.
Response was generally positive, but some thought it looked uncomfortable. To be fair, I always intended to add a cushion or a sheepskin to slightly pad the seat, but omitted it for the gallery opening in the name of artistic integrity (I clandestinely added one a week or so later.)
Just as the gallery show ended, and I thought I could finally take my baby home, I was asked to include my chair in a smaller gallery exhibition with a classmate's chair from a previous cohort of the class. His chair, Et Stykke, employed another technique I'd been interested in, the living hinge, to create a curved seat and arms from a single piece of plywood. I saw his solution as a validation of my efforts, as his design was driven by a similar desire to mitigate the hard flat seat problem endemic to CNC manufactured furniture.
Once I finally brought it home, my chair fit into my life just as snugly as I'd hoped. It took on the role of a reading chair, as well as a comfortable place to practice guitar, as the seat was low enough to allow easy manipulation of my amplifier and effect pedals. The sheepskin keeps it cozy, and a small cushion lets me sit in it for long stretches very comfortably. In the end, I couldn't be happier with my chair. I feel that it met all of the required parameters (minimization of waste, effort and hardware,) created a technique for modeling and producing curved forms in plywood (one which can be applied to future projects,) and expressed the character and beauty of both the material and the method of production, especially through the exposure of the 11 plies of Baltic Birch along the routed edges. The Allium, named for the family of plants to which onions, shallots, and leeks belong, is one of my most precious possessions. The structural grid (reminiscent of the lines cut into an onion to dice it) sits proudly on its pedestal, rather than being hidden away. The process of creating it taught me so much and made the piece that much dearer to me. While the design of the chair will be made available (what's the point of CNC made furniture if it isn't freely distributed?) this one is mine, and will always, at least in my mind, stand apart from others. I designed a mass-producible product, but I built a one-off, and treated it with the respect due any custom piece. Building it taught me about respecting industrial processes, but designing it taught me about the human experience, and how our objects impact out lives.