Module 3

Fabrication

Virtual Environments

Robert Williams

Weeks 6-7 Journal

Prototype FabricationFrom reviewing Module 2 it was felt that I had fulfilled the requirements but had lost a much better form in the process. Since I wasn’t happy with what I had produced in the module, I went back to my earlier form (right) made up of the individ-ual geometric rings.For this prototype I unrolled each ring and printed it onto 80 gsm white paper and cut out each section by hand. Working out the best size to work with was tricky because of the limitations of a A4 Printer so my first attempt was a little small. The next print out I worked out where the tabs went along the edges of the surfaces, deciding that 4mm wide was the best size for the tabs. Each ring was identical so I repeated the same process until I had made enough components to create the form. This prototype was also used to work out how to connect therings together. I looked at connecting them using the same sides (far left) but this method didn’t allow a dra-matic curve. But by similar triangles I was able to better replicate the spi-ral at the bottom of the form.

Prototype Fabrication Continued

I continued making the components and connecting them in sections using sticky tape. The paper that I used however was not very strong and could not support the weight of the branches at the angle that they protruded. The components under stress would buckle and become crushed by the other components. There was a point where the form could be balanced but was not very stable (shown by the series of photos below).

The prototype portrayed the concept of growth up and outward well from the front, however the profile veiw was very flat and didn’t convey this concept at all. This ‘flatness’ will be developed so the whole form from either view point is inkeep-ing with the concept of growth.Positive characteristics though are the geometric feel of the form overall, with the many triangular faces and pentagon openings in each component. The spiral at the bottom of the form is also an attractive part, with the spiral configuration be-ginning just in front of the hand; ‘growing’ from this point. The other curves within that make up the form are also aesthetically pleasing because of the interaction between the rigid outlines of the components to create a curving outline.

Reflecting on the Physical Properties of the PrototypeAfter completing the intial protoype I looked at how the light was going to travel through each compnent to reach the ends of each ‘branch’. In the physical model I had used similar sized trianlges on the components to at-tach them to each other, however when cutting these unneeded panels out the triangles would not always line up, with gaps forming which would allow the light to escape (shown below). From this result I went back to the Rhino model and adjusted the components so the surfaces joined to each other right around the egde. This allowed me to remove the internal walls as a means for light to travel throughout the whole form.Through the process of joining the components in this way I was able to make a hand grip in a similar position to where I held the paper prototype. This involved closing up one side of the of the components to protect the hand from possible heat but mainly to provide a strong section in the lantern to carry it by.

Original unjoined components, some intersecting with each other

Joined components

Hand grip incorporated into the lantern formComponents joined using similar triangles. The weren’t all the same size and so left gaps be-tween the connections (red ring).

Addressing the Form of the LanternAs mentioned earlier, after making the paper prototype I noted that the profile view was very flat and did not portray the idea of growth very well. To change this I added extra ‘branches’ coming off the form, bending outward. The prototype also had problems in balancing and by having the extra branches ‘growing’ in the opposite direction it will help to balance the form when being held (shown right).

Revisiting the Lighting Effects

I still wanted to have a mixture of direct and layered lighting effects and so went back to my earlier modules. The sketch of the shad-ows (far left) depicts a different form but the idea of the cuts helping to depict growth through the concentration of the light is something I would like to retain. In Module 2 I came up with a scaling cuts system through separating the form into sections and panel-ling in accordance to the section (left). The lowest would have no or very few small cuts, the middle would have medium sized cuts and the top section would have the largest to produce the most light.In transferring these ideas to the compo-nents I looked at totally enclosing the bottom rings, so there were no holes for the light to escape. In this exploration I tried to simplify the geometry and levels of triangles (go-ing left to right) however I prefer the first ar-rangment because of the complexity of the shape but feel the hole in the centre helps to emphasise this comlpex arrangement of the triangles. I decided then that the cuts would be on the triangles that create the hole and would change the frequency and size of the cuts depending on the components position within the form.

Arrangement of shadows from Module 1 Scaling cuts system from Module 2

Experimenting with the complexity of the triangles in closing up the ring

Creating the Cut PanelsUsing the ‘Dupboarder’ and ‘Offset Boarder’ functions as before, I created cuts in the triangles that made up the holes in each component. I made the decision not to cut into the trianlges that made up the width of the components so as to avoid too much complexity. If I were to apply cuts to these triangles as well, I feel that it it would make the form to busy and confronting to the viewer. Another factor was the strength of the material and allow it to be self supporting. By having these spaces in-tact, it increases the strength of each component. I made a prototype component using the offset boarder technique (bottom centre). It works well in letting light out but the thinness of the struts is a concern. The paper started to bend and did not hold it’s shape if knocked. This may also be the strength of the paper, however in future I will trial thicker, sturdier card and increase the width of the struts (which were only 2mm). Another issue was the tabs being slightly to big and pertruding past the width the of the struts themselves. In the next trial I will make sure the tabs are better positioned and of the same width as the struts.To convey the concept of growth I applied these cuts to the whole form, starting with none at the beginning of the spiral and as the it comes to the hand grip small cuts appear (bottom section), with their frequency and size increasing as the form grows. When it reaches the point when the compo-nents are branching off, the cuts become larger in size (medium section). As the branches continue out the cuts become more frequent and larger. This growth continues towards the end component until the last ones are reached, where the struts are 4mm thick and create the largest openings with every triangle cut into. The overall effect of these cuts is impressive and through the complexity of these openings, their frequency and concentration portrays the growth up and outwards of the form of the lantern (left).

Fully panelled form

Individual components showing the change in cut sizes Prototype component Scaled cuts showing direction of growth

Response to the Assigned ReadingsDesign and Manufacturing2D Fabrication or CNC (Computer Numerically Controlled) Cutting consists of a moving head (2 axis motion along X & Y) or moving bed which the mate-rial is attached or both working together. It uses three different cutting methods,A Plasma Arc- An electric arc passes through a compressed gas jet in the cutting nozzle, heating the gas into plasma; which converts back to gas as it passes the heat to the cutting zone.Water Jet- A highly pressurized water jet is mixed with solid abrasive particle and directed through a tiny nozzle to create a focussed stream. This creates rapid erosion of the material, providing clean accurate cuts. This method can cut almost any material.Laser- High intensity infared lights combined with pressurized gas is used to melt or burn the material. This method however is used only to cut materials that absorb light energy.Subtractive Fabrication is the removal of a specified volume of material using electro, chemically or mechanically reductive processes (multi-axis mill-ing processes). The milling can be axially, surface or volume constrained. Lathes are an example of a axially constrained method. Surface constrained is identical to a cutting machine. 2D Subtractive Fabrication consists of a 2 axis milling router, using a rotating drill bit following the X & Y axis’. The 3D method is an extension with the Z axis added. These methods are limited with the 4 & 5 axis millers able to create a larger range of forms.Additive Fabrication involves incremental forming by adding material layer by layer. The model is sliced into 2D layers and this info is transferred to the processing head. There are a range of processes that fall under this method catergory:Selective Laser Sintering uses a laser to melt a metal powder layer by layer to create solid objectsLaminated Object Manufacturing is a method of laser cutting sheets of material (paper or plastic) that have been laminated together into the required shape.Fused Deposition Modelling consisits of each cross-section being produced by melting plastic fillament that solidfys when cooled.Multi-jet Manufacture uses a modified printing head to deposit melted thermoplastic was material in very thin layers.These methods however require costly equipment and have long production times, resulting in little application in building design.Countour Crafting is a recent development using a fulling automated method which combines extrusion of the shell and a filling process by pouring or injecting material to form the shape. Computer controlled trowels then shape the ouside edges of the object.Formative Fabrication utilises mechanical forces, restricting forms, heat or steam to transform material into the desired shape. The constraints of the CNC Card Cutter and Laser Cutter are the size and scale that a model is able to be produced, however this is already ad-dressed in the brief. The machines are unable to cut curved shapes to represent a curved form accurately. Triangulation or tessalation of the form are possible solutions. The positives of using the machinery are their accuracy in cutting; much higher than by hand, the process is non-labour intensive and much faster than manual operations.

Digital Fabrications“Digital Technology streamlines production effectively by blending upstream and downstream processes that are typically compartmentalised.”This technology allows us to continuosly alter and develop designs with little effort, rather than making the prototype to be able visual the form and then changing it. 3D modelling provides an accurate description in the virtual world, satisfying the need for lots of intermediate models throughout the design process. Physical representations are still practical means of communicating ideas, however this new technology has broadened what we can design and the communication of these ideas.For the fabrication of my lantern I am using the 2D Fabrication methods of the card and laser cutters. Because these machines only operate on a X & Y axis, there is no depth to the model being created and so the form needs to be unrolled. Because of the restriction of the 2 axis’ ability to create curves in the form through depth, there is the requirement for the form to be flat when unrolled. To create these flat surfaces that can be reassembled into curved 3D forms, I have used triangular configurations to provide the curvature in my lantern.