DIGITAL DESIGN + FABRICATION SM1, 2017 M4 - A Confessional Space Danika
848706 Luca Lana, Group 2 Group Members : Yu chia Lim, Phoebe Goh, Pingrong Chen
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Table of Content 1.0 IDEATION Pg 6-13 2.0 DESIGN Pg 14-24 3.0 FABRICATION Pg 25- 47 4.0 REFLECTIONS Pg 48 5.0 APPENDIX Pg 49-50
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1.0 IDEATION It’s all started from the fan, its system (panel and fold) and the study of personal space to create the 2nd skin. Personal space and individual distance/ territorial behavior create different needs of personal space.Creating a personal space that is flexible is feasible. An aura of dominance can create personal space. The 2nd skin sketches in 1.0 all have a bit of views on the human form to make others recognize that the user is also a human, thus creating the feeling of distancing when get too close. 6
1.1 Object How the measured drawings are done mainly by tracing : 1. Photocopy the fan plan view in A3 size to fit the whole image & usng the tracing paper trace it out. 2. Use the Plan view drawings and draw the guiding lines to another A3 paper to determine the fan’s top view diagonals position. 3. For the bottom view, take picture in a straight position and print it out and trace it. Small stick dimension Plan Facing downwards
Facing upwards Elevation 0.5cm
0.3cm 2.2cm diagonal length : 4.4cm
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How the measured drawings are translated into 3D modelling: Measured drawing in CAD -> Extrude and make the panels -> Arraypolar for repetitions -> Orient panles accordingly -> add details, the pivot.
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1.2 Object + System Analysis The back of the fan they will stick the fan plane and the sticks
Paper shape follows the fan shape of a semicircle, not a rectangular paper.
This pivot is the main important thing
The holding sticks upper part is
When pivot is released, the whole thing can still be standalones, but nothing to hold it firmly (pivot) so it’s not really in place
The sticks without the paper planes with pivot 9
1.3 Volume
Playing with the flexibility of the fan sticks and creating spaces out of it by folding. Image on the left, top view. 10
Sketch Design #1 Different folding degree using sticks
SKETCH YOUR IDEA IN THIS SPACE USE PLAN, ELEVATION OR ISOMETRIC DRAWING TO HELP YOU EXPLAIN YOUR IDEA. REMEMBER: THERE IS NO BAD IDEA JUST POORLY EXECUTED ONES. YOU CAN INCLUDE ONE INSPIRATION IMAGE - THIS CAN BE YOUR PROTOTYPE/S OR CHOOSE FROM THE LIST OF PRECEDENT STUDIES ON THE LMS
How does this respond to your personal space? In this design, there are 3 levels of folding: 1. Folding in different folding degree = creating curves 2. Folding to the maximum = creates triangle 3. Totally folded and retractable. = expandable folds. By using this different folds & their spanable distance, I allocate it accordingly to the amount of personal space I need according to different spots.
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Sketch Design #2 Using the body as Pivot
SKETCH YOUR IDEA IN THIS SPACE USE PLAN, ELEVATION OR ISOMETRIC DRAWING TO HELP YOU EXPLAIN YOUR IDEA. REMEMBER: THERE IS NO BAD IDEA JUST POORLY EXECUTED ONES. YOU CAN INCLUDE ONE INSPIRATION IMAGE - THIS CAN BE YOUR PROTOTYPE/S OR CHOOSE FROM THE LIST OF PRECEDENT STUDIES ON THE LMS
How does this respond to your personal space? From the fan bottom view, the panels spread revolves around the pivot. Using that idea, I use the human body as the pivot, and panels will spread from the body. The longer area indicates the zone maximum and the whole thing can be folded totally or a bit to make it as a headgear personal space, protecting oneself from the weather. 12
Sketch Design #3 Distorted body to create distance
How does this respond to your personal space? This design explores on how the personal space can be created by distorting one figure, relying on people’s feeling of weirdness and disgust to the user for the user to create the space needed. In this design, recognizeable features of the head are distorted. Panels are used to create the shape.
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2.0 DESIGN Group members : Yu Chia Lim, Phoebe Goh, Pingrong Chen
“Shared joy is a double joy. Shared sorrow is half a sorrow” Swedish Proverb
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2.1 Design Development Intro We had 2 ideas. One that explores the personal space for one person and another one is for 2 person.
1 PERSON DESIGN IDEA Using Ping Rong’s idea of protecting a person sensitivity in key areas, we designed a device that protects the person especially in the crowded places. (More in 2nd skin proposed design V.1)
2 PERSON DESIGN IDEA By listening to everyone’s presentation and feedbacks, we realized that everyone is doing protecting oneself but not letting another person into his/ her personal zones. So we decided to explore on 2 person ideas and voronoi design from Yu Chia’s M1. (More in 2nd skin proposed design V.2)
In here, my M1 design is not taken,but the idea of distortion as privacy is taken. Later in M3, as we explored more on the idea of distortion, we use a different materials to achieve it compared to what I proposed in M1.
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2.2 Digitization + Design Proposal V1. 1 PERSON DESIGN IDEA Context: Crowded trams When in crowded train, people have no choice but to get close to each other. For someone who is ticklish and doesn’t like contact, this can be quite annoying. So this design proposal will tackle the issue of personal space in 3 different forms. Function of each forms: Form 1: For those wanting to save space but keeping out direct contacts. Form 2: For people who wants to block out undesirable views to a certain extent. Form 3: This form blocks out people to a certain radius. Few types of forms because different type of situation requires different kind of personal space. Form 1: Down
Form 2: Up
Form 3: Neutral
Predecent & Zonings
We chose this precedent as it had the flexibility that our group wanted to explore. However, when testing out the shape and folding method, we ran into some difficulty with cutting the material and bending it as it was too stiff. Not as successful as V2 design,
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2.3 Digitization + Design Proposal V2. 2 PERSON DESIGN IDEA Context: On the Streets
It’s an experimental idea, exploring on the idea of how letting another person into your personal space doesn’t have to be someone that is close or intimate to you. What if the user and the person going into the personal space are strangers bonded by something? In this case we use the idea of the confession room in churches. They are bonded by the sharing of personal experiences. Just like “Confession” Little conference room by Nick Ross concept of “an extremely space efficient meeting for 2 people something sought often in this modern open space”, ours is a portable meeting space between strangers to share personal experiences without interference.
Predecents 1. Sharing of Personal Space Concept
2. Looking into confession rooms & atmospheric qualities
“Confession” Little conference room by Nick
3. Looking into systems that gives that qualites
Interior of confession room
Modern confession rooms :
Traditional confession rooms:
- Minimalist. Screen in between, leaving the rest is open - Allowing someone to talk and someone to listen.
- Heavy in feeling for sense of security by using shadows - Lattice like design of screen to allow voice to pass through
Digital Weave Iwamoto Scott
By using this lattice system, we can combine the elements of both modern and traditional confession room. At certain angles the structure will appear solid, at another, it will appear light because you can see through the holes. It also gives a sense of anominity, just like in traditional confessional space.
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2.4 Further development of Design Proposal V2. Sketch development
Final Choosen Sketch
User
Stranger
Rhino development
Testing out sketch in Rhino
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Testing out same size panels
We decided to make the model more open at the back to allow easy access for the stranger and less constraining around the neck.
Idea behind the design 1. Amplifying the sound, covering listeners identity
3. Strategic positioning of user (listener) and stranger (speaker)
Using the concept of the horn or trumpet, it have a small opening for the air (in this case sound) that becomes bigger to make the sound louder. Enveloping the user inside the big opening will allow it to have personal zone and focus on listening, also protects identity.
User
Stranger
2. Covering the speaker’s mouth area The design covers the mouth area of the speaker so that other people can’t see the mouth movements.
It have been proven scientifically that the right ear will perceive speeches and information better that the left so we positioned the stranger opening and position to be on the right side of the user’s ear.
Study of System Li HongBao’s Paper Sculpture
Looking at how the paper lantern, pompoms and Li Hongbao’s paper statues to achieve curvature and flexibility. How the paper model are made in both cases:
Chinese lantern
pompoms
Paper 1: Apply gluesticks as shown in the image above
Paper 2: Alternate the gluestick application
Repeat process and stack the papers.
Put thicker materials at the bottom and the top to hold the structure.
Stretch it out
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2.5 Prototype V2. and Testing effects. We tried 2 method of testing based on how the lantern are made: Spherical and Rectangular. 1. Spherical method
We considered using this method for the mouth area as the curvature is smaller and it curves when spreads. Using the transparency paper compared to the solid paper creates a nice layers. Disadvantage is that it have a limited span compared to the rectangular method. 2. Rectangular method
It works, it helps to make it less weighing down.
We tried to flip it over & realized that the concertina folds works better when it’s been flipped upside down. Due to paper weight & no anchor points, the whole struc- The weight of the concertina fold at the top helps ture bends down. We decided to add the concertina to straighten out the strucutre while placing it below folds below the gaps. weighs it down.
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While testing it out, we realized that although the concertina fold works great, it limits the the potential of which the structure can expand to.
Trying out different material to test the whole body form, joints and creating space for effective conversation Rectangular method is more flexible than spherical so we decided to focus on it. One of the concerns is that this structure is most likely used outdoor. So we try out other materials that is water resistant. Paper is also not very durable so we look for other materials that are more durable. Holes are same sizes
Baking paper have the same properties as paper but more opaque, flimsier and water resistant.
Polypropene materials are more rigid but quite flexible and water resistant. We decided to use this material.
Testing out the joints Holes have diff sizes
Using Metal Brads :
Using Rivet :
-Easy to install the joints & flexibility -But if pulled too much the joints will come off. -Looks nicer than rivet
-Time consuming and requires much effort -Pulled too much it will come off too but better than metal brads. -Poking out more into the holes compared to metal brads.
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Looking into the Rhino modelling to make the prototype
We tried to send it to the laser cutter to cut so we can make a longer prototype but once we unroll it we realized that the panels are all not in the same shape, and it seems weird, as shown in the images above. So we decided to create the illusion of bending instead. There are 2 things we try to achieve this: 1. Trying out panels in different sizes by creating different width:
This works to a certain extent, and it creates interesting forms too.
2. Creating the panels and joints in different angles:
This method creates more degree of curving compared to the first one.
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Consideration on how to let the structure stays in its form Based on our prototyping, we realized that the form cannot withstand on its own unless its being pulled from both ends. So we decided to get inspiration from the parachute.
Using the concept of a parachute, we let the whole structure to be in open form by using a string and handles for the user to hold. The stranger would just have to come into the space and talk.
Strangers come inside
Bangles let it rest behind the stranger
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Reading Response M2 Developable surfaces are surfaces that can be built from paper. Paper have quite a lot of flexibility and possiblities to develop from a 2D to 3D. In our model, we made most of our prototyping from papers as it gives us a great insight on how the system might be able to work. Also because our predecents uses paper. Akward and inefficient solutions are often made due to designers trying to find a suitable material with a given design. The problem with abstraction is that it can create a realistic renderings but wrong physically. In Nurbs, although precise in terms of abstraction, it doesn’t show the real tension and so because it’s what you imagine the model will be and you input it in. Rhino model mostly does this, it shows abstractions. To really know what will happen in physical, it needs to be CAM and tested it out. Parametric modelling is a useful tool for us to use, especially when we have lots of the same module repeated throughout. Reduction in contrast with abstraction is to find the optimal way to transport information, rewriting the description without altering the contents. Grasshopper helps to normalize a model but then it can’t create some unnormal ones. Refactoring helps to clean up a model. In this case, during M1, before importing the CAD file into Rhino to be extruded out, I purged the file for any unnecessary layers or unused stuffs. By doing this, it helps to lessen the files and reduces the risk of slowing down or crashes in rhino files. In M1 this abstraction is done in our sketch designs, when we try to abstract the fan and its system, the panel and folding to create a 2nd skin for personal spacing. The problem with this abstracting is that most of the works looks like fashion design. Reduction can be seen in CAD drawings and the dissection of the fan to study its components and systems. The exploration of volumes kind of combines abstraction and reductions. As we are doing M2, we did a lot of prototyping. All these prototypes are to make sure we understood the systems so when we model it out into rhino, we have the background knowledge on how the system works and the possibility of the shape happening or not when we take a look at the panel tools fabrications. This allows us to have the right focus and appropriate level of abstraction to deliver meaningful results. All the prototyping also helps us to see any possible development directions.
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3.0 FABRICATION Group members : Yu Chia Lim, Phoebe Goh, Pingrong Chen Based on our personal space concept of having a moving confession room, the rhino model produced portrayed two person wearing a single designed piece but after the feedback from the M2 presentation we have decided to split the design into two so that the wearers will meet and connect to carry out the function intended. We were also concerned about the way the structure can be supported 3.0 FABRICATION on the body, as well as its flexibility, ability to maintain its shape and its
durability. There was also a need for anchor points on the body to ensure that the structure holds on its own and the feedback given is that the parachute idea won’t work.
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3.1 Design Development & Fabrication of Prototype V2.
These are sketches produced after the feedback, with major changes being the listener’s and speaker’s pieces being separate from each other and connected when desired. To increase the comfort of the wearer, more headroom is provided. Supports were also considered in this sketch as the design extends down to rest on the shoulders.
In our M2 module, we used the white polyproplene for system testing. In M3, we decided to use 0.38mm transparent polypropolene because it’s more flexible compared to black or white polyproplene. Due to its flexiblity and thinness of the material, it failed to produce the shape modelled in the rhino design as it lacked the stiffness for it to hold its shape. Another problem is that the laser cut produced obvious burnt marks on the transparent prolypropolene.
The rhino model is produced from refined design sketches after receiving feedback from M2, such as the separate head and mouth part, the increased headroom for the head piece and the anchoring of the structure on the body.
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3.2 Final Prototype development + Optimization Anomity (Visuals + Sound) Although transparent polypropolene have the flexibility we desired, it ‘s opaque so it didnt match with our idea of confession, which revolves around anomity. With anomity, the confessor will be able to comfortably express its feelings to the listener. Our attempt to anonimity is through visual effects to confuse onlookers.
We tested with holographic card and reflective foil card, and we though that the reflective foil card produced stronger visual effects to confuse onlookers. The reflection of light can be bedazzling especially if the wearer is in conditions which has bright lights. The foil also reflects the surroundings too like the image on the right. Other than visuals anomity we also tried to create sound proofing and fills the whole to create anomity. The feedbacks we got is that it’s not so effective and we should focus more on the visuals to create anomity.
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Joints (within panels - Digital)
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Our initial module that is repeated throughout the design was created by two curves curving inwards (image 1). After repeating the module (image 2) we then fabricate by dividing the module into strips in one direction from the rhino unrolling process. However, we modified the curves so that they face outwards (image 3) as this allows the place of holes onto the rhino model (image 5), which enables the fabrication process to be easier and faster as the location of the holes are marked. As the unrolled strips do not have holes at regular intervals due to the strips conforming to the planar surface, this enables us to know where the joints are located.
Joints (within panels - Fabrication)
One of the major concerns of this design is the connections between the various pieces. As shown in M2, rivets and metal brads have been tested for their strength, flexibility and buildability. We also tested on metal brads of different lengths. The best combination for our model are metal brads of 19mm and orientated to be perpendicular to the running strips. (as shown in the black polyproplene image) This reduces the resistance produced by the brads against the shape when it is connected in parallel to the pieces, as shown in the opaque polypropolene. By doing this, it makes the whole joints neater and the metal brads won’t cause resistance for the expansion of the structure.
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Joints (between mouth & head piece)
To connect the headpiece and the mouthpiece, we have tested on magnets on the polypropolene, but the magnets (above) were not strong enough to withstand the tension between the strips. Velcro was chosen instead due to its strength. We hid the velcro strip on the inside of the headpiece (right above) and create a loop using velcro on the mouthpiece (right centre). The loop is then attached to the velcro strip to create the connection of the mouthpiece and headpiece (right below).
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Reading Response Wk 6 Architecture in the Digital Age - Design + Manufacturing/ Branko Kolarevic, Spon Press, London c2003
Briefly outline the various digital fabrication processes. Explain how you use digital fabrication in your design? The types of design processes: 1. SUBTRACTIVE FABRICATION Removing specified volume from solids. (Laser Cutting, CNC Milling). Downside: limitation of 3 axial miling, limited range of form, burnt marks from machines. 2. ADDITIVE FABRICATION Adding materials in layers to create the shape. (Selective Laser Sintering, Stereolithography, 3D Printing, Laminated Object Manufacture, Fused Deposition Modelling, Multi -jet Manufacture). Downside: Limited size, costly equipment, lengthy production time. 3. FORMATIVE FABRICATION Create shapes through reshaping or deformatons such as heat or steam. Downside: School doesn’t have this. Our system is panel and fold. We need to cut out the panels and play with the folds so we decided to use the subtractive fabrication, laser cutting to help us cut out the panels in our models. We decided on laser cutting because we are more familiar with it and CNC milling is more expensive. We need to pay for the toolpathing and the cutting.
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Reading applied to design How does the fabrication process and strategy effect your second skin project? Potential effect as whole without so much 1:1 scale model prototypes “Reverse engineering” Seeing how it might looks like in the 3D model first for how it might work when human is involved and can change as much as we want until we are satisfied and make it out. Cutting out- “The fact that complex geometries are precisely described as NURBS curve and surfaces, and thus, computationally possible also means that theiir construction is attainable by means of CNC fabrication processes.” The use of this system helps us to cut weird and complex shape that we had unrolled from the our model. Shape are all weird and luckily the use of fabrication process will help us to cut the weird shapes accurately and nicely. Saving time and effort - “Digital fabrication can offers productive opportunities within schedule and budget frameworks” This is true as we experienced it in the production of the headpiece part. The aluminium foil can’t be laser cut because its made out of paper so we had to cut it manually for each panels. The problem with this is that it takes so much time, effort and human resource to do it. What can be done with laser cutting within approximately 1 day using machine took us 2 days to cut with 4 human. There’s also less mess generated.
Prototype module
Module tested out in human form
Weird shapes when unrolled, and many.
Neatly cleanly cut & less messy
Manual cut, not so clean & messy
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2nd Skin final design
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Fabrication Sequence (Digital) 1 2
3 4 5
6 The design in rhino is produced by first creating a surface (image 1, 2) and then a network surface grid (image 3)which can be tweaked and adjusted to modify the surface (image 4). After obtaining the desired shape, a bounding grid is created around the surface (5). These two grids allow the panelling tools to fit the modules onto the curves of the surface (6).
To optimise the laser cutting process and waste less material, we have arranged the unrolled strips of the rhino model in a way such that we can fit as many as possible within one piece of material.
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Reading Response Wk 7 Digital Fabrications: architectural + material techniques/Lisa Iwamoto. New York: Princeton Architectural Press c2009
Describe one aspect of the recent shift in the use of digital technology from design to fabrication? With the help of computer technology, forming tessellations of varying sizes and forms is much easier (pg 36). This is evident in our design process, as we used Rhino to form the desired effects. We started out with a plane, and created points in a grid format. Through these points, panelling tools were used to form a tessellation across the whole design. Rhino also enabled us to play around with varying thickness of the tessellation and from there, we could experiment with the different effects created. With the form, we are able to reverse engineer the design and create individual pieces to be laser cut. This is done through Unrolling. These individual pieces are then joined together with metal brads to create the final form.
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Reading applied to design Referencing from the lectures and readings, what is the implication of digital fabrication on your design ?
The digital fabrication processes allow designer a better and more efficient way of making models. By having parametric software such as Grasshopper we now can designer a more complex geometric form such as Federation Square. We no longer have to made the model from 2D drawing instead we can go on fabrication from 3D models straight.
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Fabrication Sequence (Model)
1. Pieces of laser-cut polypropolene were collected and labelled according the rhino model to enable assembly.
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2. For the headpiece which is covered in foil card, contact adhesive is sprayed on both sides of the polypropolene which will be sandwiched between the foil card
3. The glued strips are cut out by hand and relabelled. The holes are also punched through again through the foil card.
4. The metal brad is pierced through the slit at the joints of the strips
5. It is then pressed flat against the polypropolene, perpendicular to the length of the strips.
6. The brads are connecting the strips at alternating holes for each strip to create the openings.
For the mouthpiece, only steps 1, 4, 5 and 6 are carried out as it is not covered with the silver foil card.
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Assembly Drawing
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1. After collecting pieces from laser cut, arrange according to numbers labelled on rhino file. 2. Connect using brads at alternating points, e.g. holes 1, 3, 5, 7, 9 for the first strip, holes 2, 4, 6, 8, 10 for the second strip, and consecutively. (see enlarged diagram) 3. Repeat steps 1-2 for the mouthpiece. 4. Place velcro loop on mouthpiece and velcro strip on headpiece to enable connection between the two pieces.
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2nd Skin
A CONFESSIONAL SPACE
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We had decided to use the black polypropolene and not covering it with the aluminium foil because we thought it might be interesting to have two separate material to show the difference between the users and it doesn’t have the issue as with opaque polypropolene. It hold its shape and looks cool. However, during the feedback from M3, they would prefer it to make all using aluminium foil. So we decided to apply the same material throughout. Another feedbacks we got is to make the orientation of the head to follow our rhino model. We changed it at last minute because we ran into problems towards the end. So we decided to do as per the feedbacks before the catwalk. (Shown next page)
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4.0 Reflection By doing this DDF, I learnt that preparing laser cutting is not easy and the selection of materials can really affect the overall vibes of the model itself. Fabrication part is the most challenging one and time consuming because what you do in digital file is not the same when translated to the physical world. Gravity, weight, material properties, environments, all affects the overall look of the model itself. Reading and reading responses are hard too. In terms of design, I think about the sound part can be improved. Although now we block the reading of lips and the anominity, the travel of sound aspect can probably be better. This part is a bit lacking as the way we divide the job might be at fault. Next time, we need to also analyze the capabilities of the member and divide the job accordingly. While it’s true that digital process help to give us certainties, there is always something with crafting that can give the risk factor thus creating unique innovations. In this case, while we are modelling it in Rhino and fabricating it out, it’s accurate but the risk here is the material selection we choose. Throughout the whole time we never tried to apply material to our rhino model. We leave the materials selection to when we wander around the art shops and find materials that fit into the idea we wanted to achieve. It’s not really true that architect have long disconnect from crafts as they still do architectural model and do prototyping at a smaller scale. I met insistent tutors that ask us to do design developments using craft/prototype models, to break away from 3d modelling. I realized that while we do physical model, It gives some ideas along the way of making as the model itself we have a full control to it, not like digital ones where we don’t have certain controls. Things we have no control and can’t see like the gravity effects can be seen clearly in physical model compared to digital model. Utilizing the digital and the physical depending on their pro and cons will create good and unique designs.
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5.0 Credits
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6.0 Appendix Bernstein, P. (2008). Building the Future: Recasting Labor in Architecture. Peggy Deamer. Princeton Architectural Press. c2008. pp 38-42 Cheng, R. (2008). Inside Rhinoceros 4 / Ron K.C. Cheng. Clifton Park, NY : Thomson/Delmar Learning, c2008. Enric Miralles,Carme Pinos, “How to lay out a croissant� El Croquis 49/50 Enric Miralles, Carme Pinos 1988/1991, En Construccion pp. 240-241 e-sideblogadmin (2014) Green furniture award 2014. Viewed 1st June 2017. http://blog.e-side.co.uk/green-furniture-award-2014-the-finalists/ Freehugcampaign (2006) Sometimes, a hug is all we need, Viewed 1st June 2017. https://www.freehugscampaign.org/ Heath, A., Heath, D., & Jensen, A. (2000). 300 years of industrial design : function, form, technique, 1700-2000 / Adrian Heath, Ditte Heath, Aage Lund Jensen. New York : Watson-Guptill, 2000. Iwamoto, L. (2009) Digital Fabrications, Architectural and material techniques. Retrieved from Digital Fabrication LMS site. Kolarevic, B. (2003) Architecture in the Digital Age - Design and Manufacturing. Spon Press, London, c2003 Li Hongbao | Out of paper. March 18, 2013. Youtube video, Llyod,R. (2009) Most People Prefer Right Ear for Listening. Viewed 1st June 2017. http://www.livescience.com/9679-people-prefer-ear-listening.html. Scheurer, F. and Stehling, H. _2011_: Lost in Parameter Space? IAD: Architectural Design, Wiley, 81 _4_, July, pp. 70-79 Schoeni Art Gallery, Artist Workshop Series, The Making of Paper Art by Li Hongbo. March 7, 2013. Youtube Video. Sommer, R. (1969). Personal space : the behavioral basis of design / Robert Sommer. Englewood Cliffs, N.J. : Prentice-Hall, c1969. Studybodylanguage.com (2012) Personal distance divided by zones. Viewed 1st June 2017. http://www.study-body-language.com/Personal-distance.html. Surfaces that can be built from paper / In H.Pottmann,A.Asperl,M.Hofer, A.Kilian (eds) Architectural Geometry, p534-561, Bentley Institute Press, 2007. Teach Engineering (2017) Hands-on Activity: Design a Parachute. Viewed 1st June 2017. https://www.teachengineering.org/activities/view/design_a_parachute
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