Studies in Craft by Stephen Belton

STUDIES IN CRAFT

Furniture design + fabrication seminar | fall 2013 Graduate school of architecture

G|SoA GRADUATE SCHOOL OF ARCHITECTURE UNIVERSITY OF FLORIDA

STUDIES IN CRAFT furniture design + fabrication seminar | fall 2013

Collection of graduate students work | University OF Florida

ASSISTANT Professor Stephen Belton Book Editor Omayra Diaz Graphics Melissa Cortes

STUDIES IN CRAFT furniture design + fabrication seminar | fall 2013

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Matter in the Making This book represents a semester’s snapshot into the ongoing work at the University of Florida Graduate School of Architecture in exploring, discussing, and experimenting with contemporary issues of craft using furniture as the vehicle for design and fabrication. The close engagement with material offers students the chance to experiment with, and ask questions of the relation between designing and making. At this scale materiality becomes, not simply a specification but a medium by which to inquire about the nature and process of how something is made. As such, the lessons and implications for architecture are much greater than the modest scale of the work suggests. The design and fabrication of furniture represents the touchstone of our engagement with the material world, both as designers and users. Furniture maintains a critical link with architecture, both as book ending the smaller scale of form and space as it Engages human occupation and use, and as a scaled distillation of the evolving interplay between form, materiality and fabrication. Within the Modernist movement furniture became a focused study by both architects and industrial designers between material form and the methods of industrial production. Today’s advancements in CAD/CAM design fabrication present new questions regarding the dialectic of human and machine, and in turn new challenges and new opportunities in the exploration of craft. While not intended to be all encompassing or exhaustive as to the scope of the course, the following five dialectical pairs served as frameworks for class discussions, Presentations, and the understanding, critique and conceptual development of the student design work: Dialectic 1: Hand vs. Digital Craft/Design Dialectic 2: Structure vs. Surface Dialectic 3: Material Behavior vs. the Joint Dialectic 4: “Function” and/or Engagement with the Body – Ideal vs. Actual Dialectic 5: Designing vs. Making It became useful to return to these themes throughout the semester to clarify particular concepts explored in individual lines of research and design, as well as reflect upon the larger body of studio work and changing understandings of material and design with respect to historical antecedents.

The semester began by researching both historical and contemporary material and fabrication processes. Before any design took place students were asked to explore material behavior in response to various tools and operations. From this collective Research and group discussions students developed an individual line of inquiry regarding material form and process, leading to the design conception, testing, prototyping, further design development, and finally finished fabrication of a single piece of furniture. Wood, because of its availability, rich tradition in both architecture and furniture, and responsiveness and mutability to numerous tools and techniques available to the resources on hand, became the primary material vehicle for the investigations of the class. This decision was one of convenience and availability, not conceptual focus per se. Nevertheless, its near-universal focus on the part of students became a vehicle for discussions and comparison in the meaning and expression of material in design. Likewise, the resource of a newly acquired 3-axis mill became a ubiquitous tool that served to re-center experiments and discussions of craft. With the use of the mill as a tool, along with analog techniques of wood and plywood bending, material expression became not a static quality but a behavior in constant dialogue with the method and tool operating upon it. This mediated interpretation of materiality only highlights the highly processed nature of materials in production processes that industrial production techniques have determined and perfected for some time now. Manipulations through both analog and digital methods provide the opportunity to exploit material readings latent in wood, both as a natural material and industrial product. The work of this seminar was based upon design research that was iterative and non-linear. As such the finished furniture pieces, rather than definitive endpoints to design concepts may be thought of as momentary crystallizations of material expressions in constant evolution. In this manner the locus of craft begins to change: rather than the careful execution of a thoughtful design, craft becomes embedded into various feedback loops â&#x20AC;&#x201C; through the care and thoughtfulness in which they are pursued â&#x20AC;&#x201C; leading to unexpected design outcomes and material expressions. As such, the work serves as a touchstone to the changing nature of the design process in contemporary architecture and the way architecture and design more generally may find new drivers for design conception.

Stephen Belton Assistant Professor University of Florida School of Architecture 8

CHAIR IN TENSION The idea of the design derived from the testing of plywood, first, with stretching the wood and then testing is material quality. The question was asked : How can stressing plywood work as a structural component and provide some sort of comfort to the chair? The test quickly moved to question how the pieces such as the back can work in tension and compression. When the pieces are stretched to its limit it can function as a structural component. When compressed its can provide stability to the piece. Overall the question of the material durability were pushed to the limit. The process of assembling the final chair was as simple as connecting and locking into the joints created. The possibly to product a number of these chair is plausible because the material was used in an efficient manner. While creating the design of the chair the CNC Mill bit size was one constraint I encountered. This constraint lead to establishing a limitation to the size of the striation of the chair. The bit size used was 1/4”. Another process prior to stretching the ply wood was the soaking of the back. Without the soaking the striation of the chair will not give enough to make a noticeable impression of stretching. The back become the piece that would bring together the ideas of stressing the limits of the material.

18”

36”

13” (BEFORE EXPANSION)

16 1/2”

18”

2D TEST

001

002

003

BACK

SEAT

FRONT

CHAIR VIEWS

SIDE

BAACK

FRONT

Profiling Toolpath Inner 1/4” Flat End 150 ipm 0.125” stepdown 5.82 MINS

engraving Toolpath 1/4” Flat End 150 ipm 0.64” stepdown 38.89 MINS

pROFILING Toolpath INNER 1/4” Flat End 150 ipm 0.125” stepdown 5.24 MINS pROFILING Toolpath 3/8” Flat End 400 ipm 0.65” stepdown 1.35 MINS

CHAIR TO TABLE INSPIRED BY ROBERT VAN EMBRICQS RISING CHAIR THE CHAIR CHALLENGED THE RISING CHAIR BY NOT ONLY DEFINING THE USE AS A CHAIR BUT ALLOWING FOR THE CHAIR TO TRANSFORM TO A TABLE. THE CHAIR AND TABLE Pieces were built individually in Rhino, CNC milled, sanded, and assembled.

DETAILS

CHAIR- TOP/FRONT/SIDE 17

3”= 1’-0” SCALED MODELS

3 DIFFERENT POSITIONS

18 18

pROFILING Toolpath INNER 1/4” Flat End 150 ipm 0.125” stepdown pROFILING Toolpath inner 1/4” Flat End 150 ipm 0.37” stepdown

pOCKETING Toolpath 3/8” Flat End 400 ipm 0.37” stepdowN

pROFILING Toolpath 3/8” Flat End 400 ipm 0.65” stepdown

After given the task to design a table that would develop a dialogue with my partnerâ&#x20AC;&#x2122;s chair, I made the decision to create a piece that would serve multiple functions rather than a single purpose that would also share a similar aesthetic. Because sufficient storage is a common problem among the homes of many people today, I wanted to create a piece that could be easily made and reproduced using the industrial methods of a CNC machine. Thus, the idea to create a vessel for holding books came to mind-- specifically the highly coveted, oversized coffee table books that are often collected by architecture enthusiasts, students and professors alike. Three major factors went into the development of the bookshelf design. First, the limitation of a standard 4 x 8 plywood sheet presented a restriction on the size of the bookshelf itself. Additionally, a one inch offset from the edge of the plywood material was required for the drill bits of the CNC machine, ultimately determining that the maximum length of the primary monolithic piece could only be as long as 7â&#x20AC;&#x2122;10â&#x20AC;?. Secondly, the decision to bend the plywood using a series of kerf cuts established another set of rules for the overall construction of the piece. A single, monolithic piece would transform to create the outer shell of the bookshelf, requiring a set of anchor points to hold the piece in place. Finally, the typical size of these books quickly established a set of design parameters in terms of the required amount of spacing needed between each shelf, as well as the need for a design solution that would increase the structural stability of the shelves to sufficiently hold and distribute the weight of the books. The final design consideration included the concept of lightening the weight of the plywood through a series of 3D mill cuts. The goal was to reveal a hidden structural pattern beneath the surface that emerges and disappears as it moves vertically down the inner shell of the bookshelf. It also served as a way to introduce a purposeful style of ornamentation to challenge the simplistic nature of the outer shell.

DRILL HOLES 1/4â&#x20AC;? diameter drill holes for a single joint

ANCHOR JOINT Convergence of all parts, puncturing through The quality of plywood, specifically the layering of the plies and the type of adhesive used between them, had a direct relationship to the effectiveness of the bend and were crucial to the success of the kerfing process. A relatively uniform outer layer was required for where the bend would occur to insure as little cracking as possible. The direction of the grain also played an important role, as it proved to be more structurally sound when the grain occurred in the same direction as the bend, with the kerf cuts perpendicular. The images above demonstrate the subtle difference in quality between the variLAP JOINT Built-in structural stability for shelving

ous grades of plywood that were used for testing. In order to achieve the best results, a quality plywood sheet comprised of layers with substantial thickness and uniformity throughout were used to create the final piece.

In order to provide enough structural support to hold the books, four thin rails were designed to lock onto the sides of two large shelves in a lap joint configuration, as shown in the diagram to the left. Additional holes were drilled into the monolithic shell to allow these shelving units to puncture through the surface while serving as its anchor. The resulting tensile strength between the shelves and the shell in conjunction with the lateral strength provided by the lap joint ultimately aid in the success of the bookshelfâ&#x20AC;&#x2122;s sturdy construction.

BALTIC BIRCH PLYWOOD

JOINERY

QUALITY:

LOW

MEDIUM

HIGH

OBTAINED FROM:

LUMBER YARD

HOME IMPROVEMENT STORE

PLYWOOD/DOOR MANUFACTURER

COST/SHEET:

$51.35

$52.95

$85.50

Pocketing Toolpath 1/4” Flat End 150 ipm 0.125” stepdown 1.86 MINS engraving Toolpath 1/8” Flat End 50 ipm 0.10” stepdown 43.66 MINS pROFILING Toolpath inner 3/8” Flat End 400 ipm 0.375” stepdown 0.93 MINS

pOCKETING Toolpath 3/8” Flat End 400 ipm 0.25” stepdowN 0.73 MINS

HORIZONTAL ROUGHING Toolpath 1/8” BALL End 300 ipm 0.68” stepdown 6.37 MINS

pARALLEL FINISH Toolpath 1/4” BALL End 150 ipm 0.025” stepover 34.53 MINS pROFILING Toolpath 3/8” Flat End 400 ipm 0.375” stepdown 1.12 MINS

Each being fabricated from Baltic Birch Plywood, the chair and table are inspired by two main ideas. The first idea was to use a single piece of wood to create each individual piece. The second idea was to have each piece bend or fold against itself in order to hold something. In the case of the chair, it is holding a person sitting in it; in the case of the table, books or other small objects. Both the chair and table utilize special cornercurve joints that create a strong joint to allow the pieces to fold against themselves. The cornercurve jointâ&#x20AC;&#x2122;s strength comes form multiple finger joints which allow for a high surface area to be glued. The joint is cut so that the fingers do not pass all the way through the wood allowing for a curve to be made on the outside of the joint. The curve left over from this joint hides the finger joints and gives the impression of a smooth seamless joint. The chair also utilizes kerf cuts in order to bend the piece into its final shape. A kerf is the width of material that is removed by a cutting process. A kerf cut does not go all the way trough the stock of wood. The thin layer of wood left behind after the kerf cuts are made make it possible for the food to bend easily. Using the width of the cut and number of cuts you can calculate the distance between each cut in order to curve the wood to a desired angle.

ELEVATIONS

TABLE: DESIGN ITERATIONS

FLAT TABLE

JOINT IN PLACE

ASSEMBLED

TABLE: FLAT POSITION 32

BENDING TECHNIQUES Three types of bending techniques were tested in order to find the best method for creating the cornercurve joint. Three sets of test pieces were cut to the CNC mill. Varying depths of 1/16”, 3/32” and 1/8” were left on the pieces to allow the joint to curve. The first test set was bent into shape without treating the wood at all. The second was soaked in water, and the third set was steamed.

Untreated

Soak in Water

Steamed

Pocketing Toolpath Inner 1/4” Flat End 150 ipm 0.125” stepdown

engraving Toolpath 1/4” Flat End 150 ipm 0.125” stepdown

pROFILING Toolpath INNER 1/4” Flat End 150 ipm 0.125” stepdown

pROFILING Toolpath INNER 1/4” Flat End 150 ipm 0.125” stepdown 9.61 MINS

pOCKETING Toolpath 1/4” Flat End 150 ipm 0.125” stepdowN

HORIZONTAL ROUGHING Toolpath 1/4” BALL End 150 ipm 0.125” stepdown pARALLEL FINISH Toolpath 1/4” BALL End 150 ipm 0.125” stepOVER

TRACING Toolpath 1/4” BALL End 150 ipm 0.125” stepdown pROFILING Toolpath 3/8” Flat End 150 ipm 0.125” stepdown

When initially designing our chair we focused primarily on ergonomics as a way to design the form. We realized early on that the main driver for this design should be comfort. And although the word or meaning of comfort sounds relaxing, the ability to achieve comfort actually has very strict proportions that are highly tailored to the human body. Hence the study of ergonomics. That being said, aesthetic beauty played and equal part. Very early on we were interested in the beauty of bend wood and the natural curves it produced in the wood. We felt as though the correct combination with ergonomics and the beauty of bent wood, would lead to a sophisticated chair that tailored to the comfortable side of furniture design.

KIT OF PARTS

CHAIR-BENCH POSITION 01

CHAIR-BENCH POSITION 02

SEAT

BACK

LEGS

CHAIR ITERATIONS 39

LAP-JOINT For the connection between the front legs and back support piece with tied the two pieces together using a common lap joint, and add structural support to prevent pulling out with wooden dowels that act against shear force

REAR-LEG JOINT The Leg and seat condition is a simple interlocking joint that, combined the lower leg with the base of the seat, This joint not only explored the aesthetic quality of a piece penetrating through the seat, but also added support.

1'-5"

2'-8 1/2"

6 3/4"

1'-6 3/4"

1'-2"

1'-5"

1'-2"

1'-8"

3'-0 3/4"

PLAN & ELEVATION 40

HORIZONTAL ROUGHING Toolpath 3/8” flat End 150 ipm 0.5” stepdown

pARALLEL FINISH Toolpath 1/4” BALL End 150 ipm 0.05” stepOVER

pROFILING Toolpath 3/8” Flat End 400 ipm 0.75” stepdown

the deskâ&#x20AC;&#x2122;s x shape comes from the idea of a folding chair. The joint of the folding chair become my inspiration. Thus using the joint to connect the part of the desk. The design is considered of two distinct joints one for the legs and on for the surface of the desk . The design was intended to storage books on its back side. The legs are joints using a cross joint and they cross at 90 degrees, forming a simple geometry. The desks surface joints are 135 degrees which became a difficult cut. At first a finger joint was used for the straight surface . The final design reconsidered the surface of a desk as more continuous, the process of bending was used. Finally, a mold was used for the bend of the plywood veneer. It was then placed in a vacuum bag to space the veneer to the mold. Other consideration for the final chair was to thin out the legs so the overall design would weigh less.

Consideration of unit as unit

4 47

details

DAVID

DEVELOPMENT OF CHAIR PROFILE

SIDE 51

DETAIL OF JOINT

FLAT CHAIR

ASSEMBLED

FRONT

BACK

TOP OOF CHAIR

533

BOTTOM OF CHAIR

Pocketing Toolpath Inner 1/4” Flat End 150 ipm 0.125” stepdown 5.09 MINS

engraving Toolpath 1/4” Flat End 150 ipm 0.125” stepdown 9.61 MINS

pROFILING Toolpath INNER 1/4” Flat End 150 ipm 0.125” stepdown 4.89 MINS pOCKETING Toolpath 1/4” Flat End 150 ipm 0.125” stepdowN 30.13 MINS HORIZONTAL ROUGHING Toolpath 1/4” BALL End 150 ipm 0.125” stepdown 25.15 MINS pARALLEL FINISH Toolpath 1/4” BALL End 150 ipm 0.125” stepdown 38.71 MINS pencil Toolpath 1/4” BALL End 150 ipm 0.125” stepdown 4.18 MINS pROFILING Toolpath 1/4” Flat End 150 ipm 0.125” stepdow 1.53 MINS

TOP OF CHAIR 55

Pocketing Toolpath Inner 1/4” Flat End 150 ipm 0.125” stepdown 1.41 MINS pOCKETING Toolpath 1/4” Flat End 150 ipm 0.125” stepdowN 32.51 MINS

HORIZONTAL ROUGHING Toolpath 1/4” BALL End 150 ipm 0.125” stepdown 1 hr 23 MINS

pARALLEL FINISH Toolpath 1/4” BALL End 150 ipm 0.125” stepdown 2hr 10 MINS

pencil Toolpath 1/4” BALL End 150 ipm 0.125” stepdown 7.40 MINS pROFILING Toolpath 1/4” Flat End 150 ipm 0.843” stepdown 3 MINS

BOTTOM OF CHAIR

SEAMLESS CHAIR IS COMPRISED OF ONE PIECE OF BALTIC BIRCH PLYWOOD. THE PLYWOOD WAS CUT ON BOTH SIDES USING THE CNC MILL. THE MAIN OBJECTIVE OF THE DESIGN WAS TO CREATE AN ENTIRE CHAIR FROM ONE PIECE OF WOOD. USING A SERIES OF KERF CUTS, THE SINGULAR PIECE OF PLYWOOD FOLDS BACK INTO ITSELF. IN ORDER FOR THE PLYWOOD TO BEND A PROCESS OF BOILING WATER AND STEAM IS APPLIED TO EACH KERF. EACH BEND IN THE PLYWOOD IS CAREFULLY BENT AND THEN RELEASED. ONCE ALL OF THE BENDS HAVE BEEN STEAMED AND FLEXED, THE PIECE IS PULLED TIGHTLY TOGETHER, AND RODS, RUNNING THE WIDTH OF THE CHAIR, LOCK THE CHAIR INTO PLACE. THE TAIL END OF THE PLYWOOD PIECE FOLDS BACK AND SPLITS INTO THREE. THE OUTER TWO PARTS FILL IN THE VOID OF THE SEAT, WHILE THE MIDDLE PART FOLDS INTO THE BACK. THE KERFS OF THE MIDDLE PART CREATE AN ARCH TO SUPPORT WEIGHT AGAINST THE BACK. THE BACK OF THE CHAIR AND THE MIDDLE PART, PUSH AGAINST ONE ANOTHER TO HOLD BACK IN ITS DESIRED LOCATION. ONCE THE CHAIR IS LOCKED IN PLACE, THE OUTER SURFACE NEEDS A FINISH SANDING. THE SMOOTH OUTER FACE IS IMPORTANT WHEN VENEERING A PIECE AROUND IT. THE WALNUT VENEER IS CUT BY HAND AND GLUED TO THE CHAIR, ONE SURFACE AT A TIME. IN TERMS OF THE DESIGN, THE VENEER CONTRASTS THE BIRCH PLYWOOD AND EMPHASIZES ITS HOMOGENOUS NATURE WHILE ALSO ADDING STRENGTH TO ALL THE BENDS OF THE CHAIR. THE KERF CUTS, WHEN FULLY BENT, ALLOW FOR THE LINES OF GRAIN TO REGISTER AND FLOW ACROSS THE INSIDE FACE OF THE CHAIR. KERFING IS THE PROCESS OF BENDING MATERIAL USING THE NUMBER OF DADO CUTS. THE BLOCKS IN BETWEEN THE DADO CUTS ARE FORCED TOGETHER, CREATING A STRONG ARCH LIKE STRUCTURE. THE THIN PORTION OF THE MATERIAL UNDER THE DADO CUTS BEND TO ALLOW THE BLOCK TO TOUCH.

pROFILING Toolpath 1/4” Flat End 150 ipm 0.3” stepdown

pOCKETING Toolpath 3/8” Flat End 400 ipm 0.5” depth

pROFILING Toolpath 3/8 ” Flat End 320 ipm 0.45” stepdown

CRAFT + MAKING CONCEPT What initially is an obsession with the language of the elevation later becomes the generator of the design concept. Using the standard measurements of a chair as a starting point, the first exploration is on the implied connections between each intersection. These implied connections suggest the possibility of different relationships between the individual pieces of a chair, so the concept transforms into having two gestures [one formed by the front legs and the seat and the other by the back legs and the back piece], which in elevation interlock at one focal point. Interlocking becomes the technique to join one piece to another, so the focal point turns into an intricate joint between five separate pieces. In addition, an interest in bending wood brings an exploration in kerfing techniques. These involve the use of a series of deep dado cuts to remove material and to allow the wood to bend in a segmented form. Plywood, specifically baltic birch, is the chosen material and tool for exploring the design concepts mentioned before. So, the stacked layers of perpendicular grains of wood allow for the possibility of pushing the kerfing without the constraint of easily breaking the wood. In addition, exposing the zebra pattern of the plywood turns into an additional design tool. The moments where the pattern is exposed or changed reveal moments of interlocking between the pieces. Ergonomics, while secondary in the design concept, is studied in the various iterations of the chair. An angled seat and tilted back accommodates to the personâ&#x20AC;&#x2122;s relaxed body position.

ASSEMBLY OF THE HIDDEN JOINT

I THE SEAT IS COMPOSED OF TWO PIECES WHICH MUST INTERLOCK SIMULTANEOUSLY. THE STEAMING OF THE BENT PIECE IS IMMEDIATELY FOLLOWED BY THE INTERLOCKING OF PIECES IN ORDER TO PREVENT BREAKAGE OF THE WOOD FIBERS.

KERFING

r = 6” r = 6”

The mathematical equation did not apply to the back piece of the chair;12 kerfs would produce a smaller radius than desired. So, the number of kerfs was decreased to 7.

Mathematical Equation | Arc length @ 90 degrees = Circumference / 4 Minimum number of kerfs @ 1/8 thickness = arc length / 12

Direction of grain

II THE TWO FRONT LEGS SLIDE INTO THEIR JOINTS. THESE TWO JOINTS ARE HIDDEN SO AS TO GIVE THE IMPRESSION THAT THE SEAT AND THE FRONT LEGS ARE ONE GESTURE.

III THE TWO BACK LEGS LOCK THE OTHER PIECES TOGETHER.

IV THE HORIZONTAL FRONT PIECE PROVIDES LATERAL STABILITY.

KERFING TESTS

MINIMUM NUMBER OF KERFS OF 1/8” WIDTH NEEDED TO PRODUCE A SPECIFIC RADIUS.

Tilting the bent back piece becomes an important element in terms of ergonomics in order to accommodate to the person’s body position. After various tests, the solution is create a form that will essentially hold two overlapping angled cylinders. This requires the shifting of two of the same radii at the top and bottom of the piece.

OVER CALCULATING NEEDED NUMBER OF KERFS TO PREVENT SEGMENTATION. DIMINISHES STRENGTH.

18”

18.4”

TESTS TO CREATE A SLIGHT ANGLE FOR THE BACK PIECE LEFT | RADIAL KERFS PRODUCE AN ANGLED BEND USING TWO DIFFERENT RADII AT TOP AND BOTTOM. RIGHT | KERFS OF THE SAME RADIUS AT THE TOP AND BOTTOM SEGMENTS OF THE PIECE, ALONG WITH THE FORM OF THE PIECE, GENERATE A BENT BACK., ESSENTIALLY ENCLOSING AN ANGLED CYLINDER.

OVERALL DIMENSIONS + ELEVATION STUDIES

KIT OF PARTS To produce the kit of parts, the CNC mill is used to generate most of the cuts in the pieces as some of the finishing cuts are made at the woodshop. To aid in the bending of the birch plywood, steaming and soaking techniques are used to prevent the wood from breaking. In addition, a veneer is used as a structural component for the stability of the back piece.

17”

29.2”

18” 16”

TEST 01

TEST 02

TEST 03

The three iterations are a careful study on the proportions of the individual pieces in relation to the whole as well as a study on the joints and the strength they have. Mockup one has good lateral stability and can support the body, but it does not have a systematic way of using the kerfing and has two different languages [bending + crossing] that do not work well together. Mockup two shows the change in the design, which removes the interlocking of the legs at the center and repositions it on the top corner of all legs, thus generating an intricate joint at that point. It also uses kerfs in a more systematic way by repeating the technique in the seat. This mockup is very in its lateral stability and cannot hold a person, mainly because the horizontal piece in the underside of the seat at the front is removed. The back piece in this version is somewhat out of proportion, as it goes back too far. Mockup three is the final built version. It readjusts some of the joints, changes the proportion of the back piece, and reintroduces the horizontal piece in the underside of the seat at the front for added lateral stability.

Bent Back Piece

Interlocking Seat

Interlocking + Bent Seat Piece

Horizontal Front Piece

Interlocking Legs

Profiling Toolpath Inner 1/4” Flat End 150 ipm 0.125” stepdown 1.25 MINS

engraving Toolpath 1/8” Flat End 50 ipm 0.10” stepdown 48.67 MINS

pOCKETING Toolpath 3/8” Flat End 400 ipm 0.05” stepdowN 4.88 MINS

HORIZONTAL ROUGHING Toolpath 3/8” BALL End 300 ipm 0.125” stepDOWN 2.13 MINS

pARALLEL FINISH Toolpath 1/4” BALL End 300 ipm 0.125” stepOVER 13.77 MINS

pROFILING Toolpath 3/8” Flat End 400 ipm 0.70” stepdown 7.51 MINS

While the bowframe lounge did materialize as a specific piece, it was envisioned as the basis for a modular, adaptable seating system. By relying on a structurally sound frame which can be easily assembled from pre-fabricated elements, the seating surface can be changed out according to various aesthetic and functional demands. The length, width, and materiality of each element can also be adjusted, allowing for example, the bowframe aesthetic to adjust to the demands of dining seating, foldable seating, etc. The realized example utilized oak and stainless steel, both of which are relatively scarce, expensive materials. These materials do perform at a high level, and can be expected to withstand considerable abuse and exposure to the elements. However, by experimenting with various finishes on cheaper materials, the price-point of the chair could be substantially reduced. That being said, the materials used totalled only $75 when purchased from consumer outlets. The same materials could likely be purchased directly from manufacturers (and/or in bulk) for a considerable savings.

SHIPS FLAT The chair can be broken down into it’s component parts and shipped cost-effectively. Upon arrival, assembly of the frame requires only a drill with a #3 philips bit. End-users could quickly assemble the frame themselves, or retail outlets could assemble large shipments upon arrival. The savings afforded by efficient shipping would allow the chair to be priced more competitively, and units would be less likely to be damaged en-route. While the frame, as designed, could easily be shipped flat and assembled at it’s final destination, the feasibility of shipping the seat flat depends entirely on the type of seat desired. A kerfed, rubber filled plywood seat panel could easily ship flat, while molded sheet metal, bent plywood, etc. Could not, under any circumstances. Further concerns arise in trusting users or retailers to correctly assemble the entire piece at it’s final destination; joints and alignments should be detailed according to the anticipated skill level of assemblers, with special consideration given to the tools likely to be available.

SHEET METAL

FLUSH JOINTED COMPONENTS In order to facilitate efficient assembly (and disassembly, as the case may be), the joints between the Oak bows and stainless steel cross bracing was designed to be as simple as possible while remaining highly resistant to moment forces and downward compression. This flush joint transfers forces from one member to another over a very broad area, reducing the likelihood of failure, and the more insidious prospect of slowly wearing down the surfaces where components meet. The minimal movement at these points, and the broad area over which it occurs makes splintering or splitting at these points far less likely. Additionally, the flush mounting of the stainless steel bracing reduces concern over the finish quality of the back side of the stainless braces. This allowed the steel rod and plate to be welded without any concerns for tidiness, and only a quick grinding to remove spatter and allow the plate to site flush against the oak.

MOLDED PLYWOOD

MATERIAL PREP/MOLD MAKING/WOOD BENDING

OAK LAMINATE CUTTING This was a HIGHLY inefficient process! While cutting laminates on a table saw produced very accurate cuts, and oak strips with very high dimensional stability along their length, the thickness of the blade made for a great deal of waste. producing one 1/16” strip consumed 5/32” of oak off the edge of the board. In the end, each bow required ~twenty strips of oak, each 6’ long, and 3/4” wide. These layers made up a bow 1-3/4” wide. Inevitable variation in thickness of the oak strips, often up to 1/8” in thickness rather than 1/16”, as well as the addition of almost 12 oz. of wood glue per bow accounts for the increased width over the expected width of 1-1/4” (1/16” x 20 = 1-1/4”). Scaling production of bent wood products would likely require a laser cutter, band saw or some other cutting device with a thinner cut so as to waste less material.

Transfer of digitally modelled mold to MDF via full scale print. Pattern was cut from MDF with jig saw. This method proved both speedy and effective, though a laser cut or CNC milled mold would have been more accurate, if only slightly.

BENDING AND FINISHING

LAID UP IN MOLD WITH TITE-BOND III

SPLINTS USED FOR EXTRA COMPRESSION

OVER-RUN PIECES LOPPED OFF

REMOVAL FROM FINISH AFTER EXTENSIVE SANDING MOLD FINAL PASS AT 220 GRIT.

B-SIDES

GONE BUT NOT FORGOTTEN Abandoned for various reasons, in whole or in part, these chairs played an indispensable role in the design and fabrication of the realized Bowframe Lounge. The techniques, joints, materials and ergonomic proportions explored and refined therein informed the final design from top to bottom. The welding required for a steel frame, for instance was first explored in the chair pictured in the top row, while the tectonics and proportions of the Bowframe lounge were refined greatly through construction of the sheet-metal bowframe pictured below. The chair to the right, 3rd row, was stainless steel sheet metal, which was abandoned due to crimping. The chairs pictured in the second row were early digital explorations, and experiments with the aesthetics of certain material palettes.

READY MADE COMPONENTS FOR EASY ASSEMBLY The bowframe can be assembled very quickly and easily, using only a torque wrench and a #3 philips bit. The attachment details between frame and seat will vary ary based on the seat chosen; the details for the realizzed chair and the sheet metal mockups were simple yet effective, and could easily be understood and carried out by a typical end-user.

SEAT -1 pc. clip on

FRAME -10 ss bolts 1/4”-20 -2 oak bows -3 ss braces

ASSEMBLY TIME -15 minutes

Stainless steel fabrication

HARDWARE SELECTION

DRILLED AND TAPPED STAINLESS STEEL PLATE

CONCEALED JOINT BETWEEN STAINLESS PLATE AND ROD

Stainless steel pan-head 1/4”-20 bolts were used in order to ensure good compression between the plate and the oak. The pan-head allows pressure to be distributed as widely as possible across the oak bow without requiring a washer or another steel plate opposite the existing plate.

in order to minimize the number of required parts and the complexity of assembly, the stainless plate was drilled and tapped at the required 1/4”20 thread. The bolts sourced were approx. 3/8” longer than necessary - it may make sense to cut them flush, or source bolts of the proper length.

Plate is drilled through (1/2” dia), and rod is passed through the opening. Welded inside red dotted line, and ground down to a flat surface using an angle grinder with flap-disc.

FLEXIBLE & RESPONSIVE

MEFLECTO’ KERF

The oak bows flex considerably, responding to the weight and bearing of the user, effectively softening the seating surface and back. The seat and back also respond to user movement, though this responsiveness wouldn’t necessarily be seen in more rigid seats. Inspired by the rubber inlays featured on Persol sunglasses, known as the ‘Meflecto’ the kerf cuts in the seat component were inlaid with natural gum rubber, reinforcing the otherwise weakened curves, while allowing the seat to fold flat for shipment. This flexibility afforded by this composite also provides a ‘soft’ responsive seating surface, with the angle between seat and back changing according to the users weight distribution.

EXCEPT: © PROFESSOR CRAIG SMITH AND STUDENTS IN COURSES PGY 4156C & PGY 3820C PG 11, PG 17, PG19, PG 23, PG 25 PG 43, PG 45, PG 46, PG 49 PG 52, PG 57 PG 61, PG 62, PG 66 PG 71, PG 76, PG 77, PG 81

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G|SoA

Graduate School of Architecture University of Florida