Hikari: SunShade Book

HIKARI

Carnegie Mellon University School of Architecture 2014 Independent Study Hikari: SUNSHADE http://hikari-sunshade.tumblr.com/

Cover art by Bun Bu Ichi bunbuichi.wordpress.com

Advised by Stephen Lee Designed by Samuel Sanders and Yuriy Sountsov

Text © 2014 by S. Sanders and Y. Sountsov Photographs by S. Sanders and Y. Sountsov © 2014 by Lulu Press, Inc. Illustrations © by Samuel Sanders and Yuriy Sountsov All rights reserved.

Printed in the United States of America Lulu Enterprises, Inc., 3101 Hillsborough Street, Raleigh, NC 27607 e-mail: lulu@email.lulu.com

All copyrighted materials are the property of their respective owners. All final construction documents are suggestive in nature and should be verified by a licensed architect / engineer for certification. Neither designer is responsible for any damage or injury that may stem from improper or unadvised use of product.

TABLE OF CONTENTS

PROPOSAL PACKAGE ENVIRONMENTAL ITERATIONS COST ANALYSIS FINAL DESIGNS

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PROPOSAL PACKAGE

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SolShade is a project that has been long in development and is one that the upper year studio in CFA 200 has long needed.

Over the past three years of working in the

main architectural studio of the College of Fine Arts building one of the major grievances and more popular complaints voiced by the student body at large and various professors (so much so that group meetings near summer months often move outside of the studio) is the blindly offensive amount of solar infiltration and glare that the elaborate Hornbostel windows permit.

Without an effective shading system, students

and faculty attempting to work in the space on sunny afternoons are greatly hindered by direct sunlight and glare.

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1

Studio CFA 200 Often in a vein, students, attempting to work unhindered within the space, devise off-the-cuff solutions to create shade for themselves and others. Some are more conservative - students pin or tape up old plots and chipboard to the window, whilst others are more creative in their approach - taping chipboard to their heads as a pseudo-visor. Even though moderately functional and readily practical, these solutions are often temporary as the sun angle continues to move and, more often than not, are visually off-putting and far from aesthetically appealing.

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R e l a t i v e

Intolerable level

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Due to the unique and creative design of the full span central pivot windows of the studio, conventional blinds and drapery would either not be a sufficient solution or limit functionality of the windows. The window system is currently a four part system: two parts fixed window panes on either side of a one part central pivoting window pane and atop, one part clerestory ventilation window. Any applied system would have to respect each part’s limitations and functions in order to not inhibit said part.

Tolerable level

S u n l i g h t

Aft er

Time of day

1 Much in the same manner as the shades that were added to the east windows of Margaret Morrison, SolShade, conceptually, would not block sunlight from coming into the space, but more reduce the harshness of the sunlight at its most intense points. Within the course of development of this project, systems like those in place in the Intelligent Workplace, where direct sunlight is reflected onto ceiling surfaces to be utilized as indirect illumination, can be employed not only to reduce solar exposure and computer glare but also to reduce the need for artificial lighting and ultimately reduce energy costs.

Experience, knowledge, and craftsmanship will be the driving factors of this endeavor. Along with a desire to benefit and improve the working conditions and productivity of the SoArch students, the preservation of the aesthetic quality and integrity of the studio are the focuses of this Spring 2014 Independent Study course.

Bringing a wealth of past experience to the table, each student within the course has taken, completed, and excelled in both Materials and Assembly (48-215) and Issues of Practice (48-550), as well as a number of craft working, digital fabrication, and hand joinery elective courses. All students within the course are currently on track to continue their respective theses from the Fall semester into the Spring semester. That being said, each student’s thesis advisors have, in some form or fashion, experience and/or expertise within a variety of fields and departments that cover the complexities of this project. These advisors can contribute as acting advisors for the project through its duration, whilst not effecting or taking away from their primary duties with the students’ individual theses.

This project will not only be a test module which can be built upon and mass implemented, but it will also stand to expand each student’s knowledge base of designing successful retrofits utilizing unconventional building techniques and methods.

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ENVIRONMENTAL

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The environmental studies mainly focused on the nature and the quality of the sunlight in the studio space. A detailed digital model was created in Rhinoceros to simulate accurate lighting conditions in the studio at any time of the year. The digital model included an accurate study of the Hornbostel windows themselves, the lighting, wiring, and piping immediately around the windows, work tables and two types of chairs, computer tables and computers, and the rolling panels. The north end alcove was modeled and mirrored for the south alcove. The exterior was also modeled to some extent to capture any reflect light that might contribute to the conditions in studio.

This model allowed for accurate renders and timelapses to be generated for any point in the year to support the empirical notion that the studio windows require a shading system. The studies are split in two: the space as a whole and a grouping of studio tables.

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1

Exposure and Incident Light On the left is an insolation analysis for the studio space from an average sunrise hour of 6:14 AM to an average sunset hour of 6:26 PM and on the right is an insolation analysis for the studio space for studio hours, 12:30 PM to 4:20 PM. A very clear difference is visible between the two analyses in the distribution and intensity of average sunlight. In the sunrise/sunset analysis the majority of the space is lit about 42% of the time with more intense coverage near the east windows, likely due to longer morning hours on average. During only studio hours, about half of the studio gets only about 8% of the light with very intense spots near the west windows where the exposure rises to about 80%. The dark area in each analysis in the southwest is the building shading itself. This overall data means that the shading system would not need to be used during all hours that the sun is up and may actually need a variation on the east side of the studio.

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These charts graph radiation levels one week after the start of the school year, on August 30th, left, and one week before it ends, on May 10th, right. Around 11 AM the radiation is nearly 20% larger at the beginning of the year, but diffuse sunlight is about half as strong. In the beginning of the year the sunlight stays strong for longer too, dipping only 20% in six hours. While the end-of-year graph shows meteorological interference, it is less intense. From this data, the shade will have to be able to operate for several hours at a time when the sun is intense and still be available when the sky is cloudy.

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Shadow Range

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These analyses show the shadow range from sunrise to sunset at the beginning of the year on the left and the end of the year on the right. The paths of the window openings shift from favoring north-wise arcs at the beginning of the year to south-wise arcs at the end of the year. Also at the end of the year, the sun lingers at the start of the day a bit more, resulting in temporally concentrated light on the east side of studio. These diagrams could aid the managers of the space in organizing the layout of the tables and work areas within the space. Ideally with a perfect shading system the exposure of the sun should not matter, but if it was a issue the tables could be arranged to avoid direct sunlight most of the time on the east side of studio and some of the time on the west end. Also, if shading systems are used for both sides of studio, a stronger system would need to be implemented on the east side as it gets more lingering light.

These analyses show the shadow range for studio hours at the beginning of the year on the left and the end of the year on the right. Here there is also a shift in temporal intensity, with the end-of-year light lingering more closer to the west windows than the start-of-year light, which is spread out more and sometimes nearly reaches the center axis of the studio space. The sun even has a small amount of eastern exposure at the beginning of the year. Also, during the beginning of the year the sun actually casts light on the north wall, which may adversely reflect light in a way that does not happen at the end of the year. Without a shading system, to fully avoid sunlight during studio hours the space would have to be arranged so as to avoid the northwest regions revealed by these analyses. As these regions are nearly 40% of the space, that would be highly inefficient space planning and, if student habits are anything to go by, the regions would soon be occupied anyway.

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1

Renders These two renders are generated at the peak solar exposure times one week after the start of the year, left, and one week before the end of the year, right. Clearly the solar conditions are very similar. There is no direct light into studio because the sun is nearly vertical - since all the windows are vertically oriented no rays penetrate into the space. On warm days the windows would be opened to let a breeze in. Any shading system would have to allow for the windows to be able to open. Also, since there is nearly no direct light the shading system cannot be too dark - it should still feel like day in the space.

Three quarters into studio hours, also one week after the start of the year and one week before the end of the year, conditions change.

Now during both times there is strong sunlight penetrating into the space. The end-of-year lighting is nearly perpendicular to the axis of the space, casting large rectangles of blinding light onto work spaces. At the start of the year the lighting is less unbearable but still very intense.

These conditions would be the worst case scenario for a shading system. When the harsh light begins students should be able to easily roll down the shades as needed.

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Work Area Layout

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On the right is a schematic layout of studio in section and in plan.

Sectionally, more than half of the space is unused for work or habitation. The building continues for two floors above and below.

In plan, almost the entirety of the space is the studio, with two alcoves on the north and south reserved for critiques. Groups of work tables are shown in red.

Following are analyses of a pair of such groups.

On the left is an insolation analysis for two typical six-table arrangements on the west side of studio (west is down) from an average sunrise hour of 6:14 AM to an average sunset hour of 6:26 PM and on the right is the same for studio hours, 12:30 PM to 4:20 PM. One set of tables is slightly to the right of a window, the other is slightly to the left. Comparing the two, the left analysis indicates that very little light is added beyond studio hours, meaning that most of the light that comes in on such a table arrangement is during studio hours. However, on average 30% less light is concentrated over the entire sunlight period compared to the studio hours period. In both cases, the light is strongest nearest the windows, with the gap between windows casting a shadow on part of the left set of tables. Otherwise, the inner tables get 30%50% exposure. This consistent intense light is paramount for a shading system to fix; the shade also has to cover the entirety of such table arrangements.

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2

Work Area Shadow Range These analyses show the shadow range from sunrise to sunset at the beginning of the year on the left and the end of the year on the right for two typical sixtable arrangements. The conditions during both times are nearly the same, with the end-of-year lighting being slightly stronger. Note in both analyses that the strongest overlapping light is not on the tables but on the floor between the tables, near where a student would be sitting when working at one of the end tables. Also, in this double arrangement the left set of tables gets nearly no light compared to the right set. This kind of daily imbalance could generate irritation between students attempting to work in a uniform environment throughout the day. If it were not for light’s propensity to bounce around, the left set would get next to no light while the right set would get significant light and the floor would be blinding. The shade should address all of these issues by homogenizing the light.

These analyses show the shadow range for studio hours at the beginning of the year on the left and the end of the year on the right for two typical six-table arrangements. Both analyses still display a significant solar exposure on the tables. While the exposure is not as great as it is for sunrise to sunset, which means that the sun reaches the tables for some amount outside of the studio period, it is still enough to cause discomfort and disrupt performance levels for any students within the exposed areas. Note how, if the table groups were to be split into their individual six tables, only one table, in the lower left, would be without any direct solar exposure and only two tables, in the upper right, would receive partial solar exposure for both periods. In the later analysis the tables in the upper left receive a little less light comparatively.

The lower left table of the group on the right would be completely unusable during studio hours for either period.

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Work Area Renders

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On the left and on the right are renders of a typical arrangement of two sixtable groups on the west side of the studio space. These renders are taken at the peak direct solar exposure one week after the start of the year on the left, at around 11:00 AM, and the same time one week before the end of the year on the right. Note that both renders do not show significant solar exposure on this area. That is because the peak solar exposure is determined globally and at both of these times the sun is shining overhead, at an angle that does not reach studio. That does not mean it is not an issue, however. These renders do not show it, but solar exposure visible outside, on the roof above the Great Hall, would produce significant glare. This glare would make it uncomfortable for anybody looking outside or having that view in a part of their vision.

Also, indirect solar rays would heat the space and cause temperatures within discomfort levels.

On the left and on the right are renders of a typical arrangement of two six-table groups on the west side of the studio space. These renders are taken at the point the sun is most invasive in studio one week after the start of the year on the left, at around 5:00 PM, and the same condition, at around 5:17 PM, one week before the end of the year on the right. These conditions are significantly different than the renders above. Both have massive amounts of solar exposure. At the earlier point in the year, more than four tables are completely unusable and regions near two of the desks would be uncomfortable to stand in. At the later point in the year, the exposure radically increases, nearly nullifying the lower group of tables. The sharp regions on all of the exposed tables would greatly interfere with paper work, with laptops and monitors, with overall glare from the relatively bright surfaces, and may even bleach any work left on the tables.

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Solar Area On the right is a solar area diagram, showing the region of the sky when the sun first enters the studio space until it reaches halfway through the space for every month that students are in studio. When the sun is at any point in this region, it is shining into studio and impeding upon the students there. This kind of analysis shows that, closer to the summer months the sun is longest in the sky and rises highest. That means that it reaches studio at a steeper angle and transitions to a shallow angle slower, compared to months closer to winter. In December the sun’s path is shortest, and in May the path is longest (but only a bit longer than in August). Throughout the year, the sun reaches past the halfway point in studio at about the same angle. That means that after a certain point, assuming the day is not cloudy, HIKARI would have to be used at any time of the year.

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Time-lapses

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On the left and on the right are QR codes linking to videos on the project website which are time-lapses of the temporal sunlight and shading condition in studio one week after classes start from sunrise to sunset. On the left is a video looking across studio and on the right is a video looking down studio. The video on the left shows that the morning light in studio is also somewhat oppressive, perhaps indicating that a shading system would be useful on the east side of studio as well. It is not as pressing as a system on the west side, however, because students generally are not working between sunrise and noon. Later on in the video can be clearly seen solar exposure on the computer monitors. Glare like that makes the monitors nearly unusable, as any image on the monitors is washed out. Also note how, towards the end of the video, the sun even shines on the far wall. The right video shows similar issues, except for the entirety of studio.

On the left and on the right are QR codes linking to videos on the project website which are time-lapses of the temporal sunlight and shading condition in studio one week after classes start during studio hours. On the left is a video looking at a computer bank in the northwest corner and on the right is a video looking down studio. From the video on th left it is clear that over the course of studio hours the light from the windows passes across the monitors of several computer stations. From the video on the right, between 3:00 PM and 4:30 PM the solar exposure reaches nearly every work table and greatly impedes anyone who would be working in the spaces between the work tables. That period of time is more than a third of studio time and anyone attempting to work during those hours, or have a desk critique, may find doing so very difficult. In this kind of scenario a student or several students would have taken steps to block the sun from their work area.

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ITERATIONS

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Following is documentation of the design iterations that led to the final product design. Initially there were two ideas on how to tackle Hikari - either the system could be a fixed semicircle that went around the window and moved up and down, or it could be a flexible system that collapsed into the space of the window. Both systems appeared to have pros and cons - the first was rigid and strong, but stuck out whenever the window was not open. The second was compact, but its rigidity and strength were questionable. For both versions the questions of material and operability remained relevant. Ultimately, the second system was chosen as reducing Hikari’s impact on the physical space of the students in studio was more important than the reliable function of the system itself. The flexible system became known as BunG because it relied on the mechanics of a bungee cord - a fairly rigid entity that stretched to accommodate.

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1

BunG 1 BunG 1 was the first attempt at creating a mechanism. It was a scale model of the window, simplifying it to a rectangular frame. Since the most important aspect of the window was the rotating element, that was also modeled in scale.

The modeled mechanism itself did not bother taking scale into consideration as this version was more of an exploration of the overarching mechanism behind the BunG concept. This was more of a test of whether a bungee cord running across the window, while the window was able to operate, would flex and stretch to accommodate.

The strings and wheels were also out of scale.

The mechanism itself consisted of two bungee cords, each attached at the top and bottom of separate strips of paper that were supposed to fold, and the bottom bungee cord was attached by strings around wheels that fed into a single cord. This mechanism established the basics of the Hikari design - bungee cords keeping it taut, strings running over wheels to connect to a control at the bottom, a material that overlaps and that folds into itself, and semi-permanent attachment.

One key aspect of the design that we learned was that relying solely on the laser cutter

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1 to fabricate all of the elements was unreliable. For this version all of the components had to be glued several times so they would stick together, but even when glued they were flimsy.

The folding material was also unreliable, as it did not fold well and folded in unpredictable ways. It’s inflexibility was not critical however - it was more important to determine a system that would work with the geometry of the window first, and then we could develop the material separately.

The strings, however, worked fairly well. The material of them in this version was a plastic twine that would get undone easily, though it worked well enough as a string until we switched to fishing line. Attachment was always by knot, though attempts were made to melt it together which were not always successful. The bungee cord itself was actually too strong for this scale and was one of the things which contributed to us switching from the scale model to a full size working environment. At this scale it was difficult to operate the model window without tearing at the paper or the strings.

The QR code on the right links to a video of the mechanism working to some extent. Due to the unique nature of the studio window the operation of the system over time was an important factor, and nearly every version of BunG was videotaped to see how it worked with the window.

In retrospect, it is also interesting to see how the design went full circle, with BunG 9 using some of the basic principles established in this version - attachment at the edges, a folding material, connecting the material at intervals, and naturally the pulley wheel system.

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2

BunG 2 and BunG 3 BunG 2 was a conceptual stage version only. It expanded on the ideas of BunG 1 but was still at a scale. Therefore it was decided to abandon it while it was in the sketching phase and continue to BunG 3, which was at full scale and used systems and materials that would work at full scale, like plywood for the frame and the actual bungee cord.

BunG 3 was approached from two directions. One direction was to actually purchase a commercial blind and take it apart to see how it worked. The idea was that instead of developing a folding pattern from scratch we would use one that has been proven to work and modify it. We discovered some key elements from that approach - the way the slats are strung uses two types of string - ladder tape to hold them parallel, and guide strings running through to pull them in sequence. Since we wanted a continuous material, we lasercut some vellum to fit the strings in the commercial blind. This was a laborious process but bore fruit, as the system functioned even with the replaced material. One downside was that, due to the flexibility of vellum, there were tails on either side once the material moves past the guide strings. The vellum by itself, from some testing with real sunlight, was too opaque so we made a Grasshopper script to generate perforations. Different spacings and sized were tested - it was determined that even very small perforations let sharp sunlight in, so moving forward we decided to drop a perforated system.

The second approach was to create fixed frames from which the blind system would hang that were mounted on a single bungee cord. This system was made on a small scale, ignoring for that moment the scale of the window, to test the properties of the bungee cord.

It was rapidly discovered that the bungee cord was still fairly flexible even when taut, but it was thought that could be remedied with even greater tension in a future iteration. A rudimentary wheel system was made that fed the guide strings of one set of blinds through the plywood frame.

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BunG 4 and BunG 5

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BunG 4 took the structure of the commercial blind and reproduced it in plywood. BunG 4 was the first iteration to take into account the full scale of the window, establishing a method of clamping onto the elevated horizontal frame that lasted for most of the future iterations. This time two long bungee cords ran through the system in an attempt to keep it in tension - it was still important to develop a system that was flexible in relation to the motion of the window over any other function. For BunG 4 we purchased pulleys, establishing that manufactured wheels trumped ones made by lasercutter.

The idea was an extension of the design of BunG 1 - guide strings would run from each of five separate blinds to a corner wheel, where they would run down to a winch. The winch itself was also prototyped, though it was not connected to the whole system. The material that was tested this time was a silver solar film.

Overall, however, BunG 4 failed. The bungee cord would not hold itself in any manner, the pulleys were difficult to attach, and the material was too weak against the sun. It was only successful in that a good clamping system was developed and it was established that we would get the majority of our raw parts by ordering online. The QR code on the right shows the failure.

BunG 5 was a last ditch effort to squeeze functionality out of a system that relied on the bungee cord for support and was nearly double in complexity compared to BunG 4. However, in working on the design of BunG 5, we realized that, with all of the support plywood in close proximity to itself, there may have been a way in which the plywood itself became the primary system and the bungee cord only provided reflex tension.

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4

BunG 6 BunG 6 was a major shift in the design and was the first iteration that promised success. The revolutionary change was the development of interlocking plywood segments, each sliding into the next or sliding out as the window pushed the system. A bungee cord was meant to run across, hitting each segment and thus giving the whole system tension. This design eliminated the reliance on the bungee cord as a support system without eliminating its tensile usefulness and provided a nearly horizontal framework from which a material could hang. The clamping frame was also expanded, now featuring a horizontal bar that kept the whole thing connected. Wheels were purchased and installed that would hold the guide strings for each blind. Also, it was decided to go from five segments to four as it was more efficient and, as at the time we still considered cutting the material on the laser cutter, made the blinds about two feet in width. This time the winch mechanism was fully made and installed, connecting to the top elements.

This was the first time the entire Hikari Sunshade was made, not including the material. The design of the winch allowed it to crank in one direction but stop in the other via the use of a little hammer. The hammer could be lifted separately to release the system. The winch had a handle that allowed operation.

For a test, one single horizontal piece of plywood was strung through the system and to the winch, to simulate a blind. It worked, but due to the winch wheel being fairly small took many turns to move up.

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4 Meanwhile material development continued.

Since the silver solar film was not strong enough, we went up two ranks of darkness to one that was nearly black in dim light but fairly translucent in sunlight. The image on the right shows the comparison - the orange patch on the left is sunlight through the material and the bright patch on the right is pure sunlight.

Despite the visual oddity this material was a very good choice - it worked, it was flexible but not flimsy, and it matched the size of the blinds we were making. It was fairly expensive however, so we were hesitant to buy a lot. Another issue of the material that we tested was its behavior in regards to wind. For this test we strung up the rest of the horizontal pieces, incidentally testing how well the winch worked, and attached paper towel strips to the strings to serve as unrolled material. Even these small pieces were enough to be affected by wind out of the window. A solution that we proposed and later implemented was to simply add a flexible piece of string between each bottom piece of each blind, and attach the end points of the end blinds to the inner frame of the window on special guide cords. This would limit the amount the window would fly out due to wind without impeding its retracting function.

The QR code on the right shows the operation of BunG 6. One can compare the significantly reduced sag compared to BunG 4. For this iteration the system had to be manually retracted because we had not installed a bungee cord - we were at first only testing the new mechanism.

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5

BunG 7 BunG 7 was an enhancement of BunG 6 as it closely tackled issues of sagging in the main mechanism, weak joints in the support mechanism, standardizing the parts, adding support at the ends, and beefing up the winch in general. From here on the major systems were decided upon and only small tweaks were made.

With the sagging partly solved a bungee cord could be run through, allowing us the first real test of a working bungee system. It worked well enough, though it took several bungees working together to provide enough tension. This was fully a function of the size and strength of the cord we had.

The way the bungee cord was strung initially was that it was attached at one end of the frame and then wound once around each far tip of each segment where there was a protruding bolt. Once it went through three protrusions it was attached and stretched at the other end of the frame. The window made contact with the plywood segments, ensuring a smooth, continuous, and rigid pressure against the system. When the window was opened, the bungee was stretched, when the window was closed, the bungee relaxed, pulling the system together.

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5 With this iteration we made a slight shift in the way the material was handled. Up until this point we thought the material should have folded, but when a large piece of the solar film arrived in a roll (that we ordered), we got the idea that the material should roll. This eliminated the possibly tedious task of threading ladder tape and guide strings through four sets of the material. Also, it would look a lot cleaner, with less distortion along the plane of the material.

This change required two modifications: creating a mechanism that rolled as it moved up and finding a type of string that could grip and release the bottom dowel (as it became) as it was pulled up. The solution was in a ball chain and gear system, where a slightly toothed gear on the bottom dowel would grip a ball chain, a metal string with tiny balls equally spaced, and turn as one end of the chain was pulled up. Each segment only needed the ball chain setup on one side; the other side could be just a string, which we decided should be fishing line due to its thin size and its strength.

The initial test of the ball chain system used basswood gears and wheels and worked well enough, though it was quickly determined that they had to be made out of acrylic since the ball chain and fishing line on either end were slipping between the gears and wheels (each set was made of two gears or two wheels) and collapsing on the bolt within, causing a failure.

Overall, BunG 7 was a success and many of the elements established during this iteration were carried over into future versions.

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6

BunG 8 BunG 8 was a further refinement of the systems of BunG 7. It was a concentrated effort to eliminate the sag, to finalize the wheels and fishing line setup, to determine the optimal shape of the segments, further test the ball chain system, and refine the material.

The sag was deemed inevitable to some extent due to the plywood elements bending, no matter how well each segment was glued or pressure fit. Therefore the only way the sag could be counteracted was by adding more bungee cords.

This is where two innovations occurred. The first was a more efficient method of stringing the bungee cord - due to the way the segments slide into each other, it was possible to attach the bungee cord directly to each of the joints, bypassing a connection to the far end of the main frame completely. The other was creating a new bungee cord that ran from points on the main frame to the center joint, taking advantage of the fact that, relative to those points, the center joint almost moved on a cylindrical surface (with the points forming its axis). This secondary bungee directly counteracted the sag and, combined with the stronger bungee setup across the segments, nearly eliminated it.

For the wheels, it was decided that each segment would have its own track of wheels to reduce congestion. As a new set of fishing line/ball chain strings were added, a new wheel was

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6 there to accommodate them. This meant that, by the end, there were four separate sets of strings that were to go down to the winch at which point they were to become one. This worked for the most part, though the shape and angle of each set of wheels still needed tweaking so that the strings did not slip between the wheels.

The shape of the segments was streamlined for this iteration. The reality was that they were made of plywood, and plywood is dense, so they added considerable weight to the whole system, and that combined with the fact that it would be flying almost two feet into the air any time the window was opened meant that we had to reduce the overall weight as much as possible. This was done generally by slimming the shape, cutting out mass, and optimizing the distance between elements.

The ball chain system was tested this time with acrylic wheels and gears. It worked well enough, though due to a quirk of geometry produced sag in the material every time it was rolled. The problem was as such: for every angle of rotation, the gear moved more distance up the ball chain than the core dowel moved along the material, due to the gear having a larger radius than the dowel. That means for every distance X that the gear rotates along the ball chain, and the material moves Y, there will be a sag of X - Y. This was later remedied by making the gear smaller.

Lastly, we experimented with a new, more popular material, shade cloth. On the right is a slightly unfair comparison between the black solar film and beige shade cloth. The reason for the unfairness is that the black film has a white opaque backing on behind it that hides the actual translucency of the solar film. Otherwise, the shade cloth was deemed superior - while it was slightly worse at solar transmission, it had a better texture, was not so oppressive or mistaken for a trash bag and it was significantly cheaper - we bought all we needed and would later need in one purchase, while we strongly hesitated to even buy half of what we needed of the solar film. It also rolled much better - the solar film had to be extremely carefully cut and attached to the dowel and on top of that it stuck to itself.

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7

BunG 9 BunG 9 was the last iteration that was physically made and was supposed to be the version before the final. Despite that, it was still host to a few changes and innovations. The entire process for cutting the shade cloth, stapling it on the dowels, and rolling it up was developed as we worked on this iteration.

Since the shade cloth is made of plastic bag, we opted to use a hot wire cutter and carefully pass it through for the entire length of each segment. The top left image on the left shows a comparison between a wire cut edge, left, and a knife cut edge, right. Once each piece was cut, it was stapled with a pneumatic staple gun into each dowel. This was done very carefully by clamping one end and pulling the other taut, then taping the cloth to the dowel temporarily, then stapling it. Once the material segments were done, they were attached to the rest of the system.

Everything was updated to reflect changes from BunG 8, and when everything went up, before the strings were attached, the system was basically functional.

It was at that point that another change was made in the design of the material and string mechanism - the gear, wheel, and ball chain

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7 system was attempted but the gears gripped the ball chain too well and, since time was short, it was decided that it would take too long to develop new gears and a new system was thought of.

The new system consisted of evenly spaced loops along each segment of material that, as the bottom dowel was pulled up (without rolling), would get caught and cause the material to fold. This had the added advantage of adding stability and rigidity to the material segments. The only downside was that, since the material no longer rolled up, it needed a lot of space at the top.

BunG 9 was the first time we tested the string connectors at the bottom of each dowel, and thankfully that system worked without any issues.

Also, we used industrial strength Velcro to attach the winch to the window and planned to do the same for the top frame, though a miscalculation in the model prevented us from doing so.

Overall the system worked well. There was some tampering with the winch which caused it to fail, and since the new string system was untested it also had some issues. The shade could move in and out with the window, and could be operated to go up and down. When the sun shone it reduced glare, light, and heat, creating a superior working environment that was comfortable and relaxing.

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COST ANALYSIS

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The cost analysis section goes over material and financial costs throughout the development of Hikari Sunshade. From the beginning it was evident that the process would involve many iterations and definitely full scale modeling after some point. We had access to the School’s dFAB lab facility and the studio computers had design software that we could use, so on the computer and automation side we were set.

On the raw material side, we had to manage

purchases ourselves. The initial iterations used mostly plastic and wood items, which we could purchase through the School from dFAB and from Wood Shop.

The later iterations more and more involved using parts that we found either on Amazon, McMasterCarr, or other individual retailers. Throughout,

we

tried to purchase only what we needed since we could not rely on the School for funding.

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1

Large Raw Materials Purchases from Wood Shop: $23.68 Misc. plywood purchases $16.74 Misc. plywood purchases $91.95 Misc. plywood purchases $63.94 Misc. plywood purchases $196.31 Total These costs were accumulated over the semester as we bought various types of plywood from Wood Shop. The types and sizes of plywood we purchased varied: we bought baltic birch, phillipine mahogany, 1/4”, 1/2”, 3/4” and any size from 2’ x 2’ to 5’ x 5’. We also purchased large scraps. Most of the plywood was used for CNC milling.

Purchase from Ben Meadows: $40.25 12’ x 12’ Shade cloth $12.69 S&H $52.94 Total The purchase of shade cloth from Ben Meadows was the only other source of large raw materials, as everything else was much smaller in scale and shipping size (if ordered). While we did use acrylic scraps, and if purchased at full size would have been listed as large raw materials, they were free and are not listed.

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Small Parts Purchases from Lowe’s: $9.78 18” x 24” Acrylic $2.30 Fender washers

$1.18 Acorn nuts $0.80 5/16” Bolts

Purchases from Amazon: $3.09 Pulleys

$1.44 1/4” Bolts

$8.74 Seal

$1.18 Acorn nuts

$0.66 1/4” Bolts

$17.90 Bungee cords

$1.76 Lag bolts

$2.46 3/8” Bolts

$31.09 36” x 9’ Privacy film

$0.98 Plastic twine

$0.44 3/8” Nuts

$2.54 Mounting tape

$3.97 Bungee cords

$0.44 Washers

$20.42 Tax and S&H

$18.98 1/2” Pneumatic staples

$0.70 Washers

$83.78 Total

$5.98 Paste wax

$8.97 Industrial velcro

$2.30 Fender washers

$1.00 Steel rollers

$2.74 Washers

$1.57 1/4” Nuts

$4.28 Hanging adhesive $1.18 Eye hooks $8.94 48” 3/4” Dowels $1.28 1/4” Bolts

2

Purchases from McMasterCarr: $1.41 Aluminum rod

$16.97 Black window film

$2.80 Aluminum rod

$8.94 Bungee cords

$15.30 Pulley wheels

$4.76 Pulleys

$9.80 Large washers

$21.97 Platinum window film

$8.50 Pulley wheels

$0.40 1/4” Bolts

$9.91 Tax

$14.70 S&H

$0.44 1/4” Bolts

$149.18 Total

$52.51 Total

$0.48 1/4” Bolts

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2

Small Parts Purchase from Ball Chain Manufacturing: $11.82 Ball chain spool $8.00 Shipping $19.82 Total Purchase from Target: $2.36 Mini blind $0.17 Tax $2.53 Total Purchases from the CMU art store: $3.95 Recycled plastic $3.45 Fishing line $0.52 Tax $7.92 Total Many of these items were reused for each BunG iteration. There were some items which were used only once, if they were an idea that was not working or was dropped, and some items which were not used at all since they were more for inspiration

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or material testing rather than implementation.

The fastening parts were determined early on and future BunG iterations were made with their sizes in mind. Not all items were fully used - for example much of the ball chain remains on the spool. Overall, however, our purchases were fairly efficient.

3

Cost Summary $149.18 Lowe’s

Mc

$83.78 Amazon $52.51 McMaster-Carr

$7.92 CMU art store $563.99 Total

azon

CMU art store

Ca rr

’s e w o L

Am

Wo o

dS

s dow Mea Ben

$19.82 Ball Chain Manufacturing $2.53 Target

Ma ste r-

Target

g n Mf Chai

$52.94 Ben Meadows

Ball

Total cost: $196.31 Wood Shop

ho

p

The total cost from all of the sources we used to develop Hikari Sunshade came out to over half a thousand dollars. The most significant contributor was Wood Shop, which made sense as most of each BunG was made of plywood of various thicknesses. The next significant contributor was Lowe’s which provided fasteners, adhesives, and some raw material. Then, Amazon contributed what could not be found in Lowe’s. Ben Meadows provided the shade cloth, which was a fortunate purchase as we only needed to buy it once. McMaster-Carr also complemented Lowe’s with miscellaneous purchases. We also used it to do material cost and quality research. Ball Chain Manufacturing provided the ball chain, which we did not end up using, and lastly the CMU art store and Target provided some miscellaneous small things.

On average, each BunG cost $62.67, but a complete BunG from scratch would probably be about double that. That kind of calculation would have been done for a final version.

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FINAL DESIGNS

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The final design is a conceptual extension of BunG 9.

There was also considered a radical reimagining taking into account existing large scale shades, but that was never developed fully.

The conclusion of our work resulted in a working,

but flawed, design. We achieved a system that provided shade, that opened and closed with the window, and that was operable so that it could be retracted when not needed. However, there were major issues with BunG 9. The winch was broken, the fishing line could jump the wheels, the material was poorly cut, and the clamping system needed enhancement and adhesion.

BunG X was a concept that we would have

proceeded with but instead decided to offer it to the School as a tentative proposal.

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1

BunG X The final design features a number of enhancements that would have fixed all of the issues with BunG 9. Overall the design would have stayed the same.

The first enhancement would have been the frame. BunG 9’s frame was almost entirely correct except for a small gap that was not accounted for in the model. This gap would have been corrected by placing a 1/4� piece of plywood at each end of the frame, gluing those pieces to the large frame pieces, and then applying Velcro to both the window and the thin plywood. This would have complemented the clamping on either end.

The second would have been the pulley system. This would have involved refining the way the wheels are mounted to prevent the strings from jumping tracks. Also, we would have had to optimize the way the strings are ultimately attached to each other to ensure it enters the winch box smoothly.

Third would have been the loops attaching the material to the fishing line. With BunG 9 they were too short and were fairly hairy. For BunG X we would have done additional research to find something like plastic or metal clasp rings for this purpose. Also, we would have inserted wire

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1 gauge (looking at 18 gauge) at the same spacing as the loops to give the material some rigidity.

Fourth, the winch would have been designed to its full specification, this time using super glue and more precise milling and stapling. Also, the inner wheel would have been redesigned to hold the fishing line better.

Fifth, we would have added guards around the wheels at the ends of the dowels (also probably changing the dowels to either metal or plastic extrusions) so that the fishing line could not slip off. We would have also changed the simple fishing line connections between each segment to a continuous thin bungee cord or elastic running through each segment as the means of keeping them together when down.

Lastly we would have compiled construction documents to help the School in making more Hikari Sunshades if they so chose. The construction documents would have involved detailed explanations of where to source the materials, how to cut them, how to prepare them for assembly, how to assemble them, and finally how to mount the entire system. It would have been a lasting contribution to the School.

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