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| Index: First Grid Test
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21_04_06 I've done some testing on an initial test rig. Some of the effects from this rig are posted on the home page (Click the current work title bar at the top to get there). Below are some quick renders of part of the grid. Each hole through the grid has a slightly different orientation to let sunlight through at a different time. This acts as a shading device, allowing a small amount of direct sunlight through a specific part of the grid.
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| Photo to show the shading effect of the grid. | First test rig | ||||
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| The light effect through the grid onto water. | The light effect through the grid onto a fine mist. |
| 25_04_06 I started drawing up the grid. The grid is a 23 by 23 array of holes or 'combes' (as in honeycombe) each one orientated to a specific sun angle. In order to create the angles for the grid I split the year into 24 from the winter solstice on the 22nd December to the summer solstice on the 22nd of June. The sunlight hours of each day was then split evenly into 24. I am working from a sunrise at 10° altitude to a sunset at 10° altitude because of the difficulty in angling a grid to 0°. The spreadsheets showing the exact dates and times of each section of the grid are posted on the right (click the images for the pdfs). I'm now in the process of turning this data into the grid. A screen-shot from is posted here. |
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Arraging the
sunpath angles into the grid array. |
Spreadsheet showing
working for the grid. |
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Begining to arrange
the sun angles to form the grid. |
Spreadsheet of
individual times for each of the 24 dates. |
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Finished sunpath
drawing from the data in the spreadsheets above right. |
Translation of
the data above into a sunpath drawing. |
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I have finished modelling the grid in CAD. The slots just need to be made before it can be laser cut. I'm planning on runing a test at 1:10 scale before embarking on the final version. A pdf of the cut-outs is on the right along with a virtual model of the grid and two animations. [The animations may need to be downloaded to your hard disk and opened from there to work properly.] Each section of the grid needed to be modelled as a surface and aligned with the sun path data before being laid flat using an unfolding alogorithm. The Prism Array The prism array disperses this light into its constituent colours, each sunangle will produce a very slightly different spectrum as the sunlight changes colour. Essentially the spectra through the prisms are a representation of the time of day and year, each spectrum created by the prism array differs very slightly in colour spread and angle. The idea is that this heightens the observers experience of the ever changing sun angle and the character of the light at different times of the day and year. |
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| Cut-outs of the grid laid out for laser cutting (pdf). | A view of sun through the grid at 1300hrs on the 8th of August, London. | ||
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| Animation of the sun moving over the grid. (The moving black patch is the shadow cast by the grid shading the sun). [right click 'save target as'] | Animation to show the changing view through the grid. [right click 'save target as'] | ||
| 02_05_06 Some sample nozzles arrived from Sprays today for me to test. Two types arrived one which works at mains water pressure (black) and the other at 100psi (white). The main pressure nozzles sprays at 3 gallons/hr and the high pressure at 1 gallon an hour. Tests to come. |
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Sprays
supplied nozzles for testing |
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| 02_05_06 Designing the Prism array in GC The prism array was draw using Generative Components (GC) a piece of software developed by the SmartGeometry group and Bentley systems. The software is a 3d parametric CAD system which uses a scripting language. It is in pre-beta stage so it is not commercially available yet. The license was provided as part of a workshop organised by Sean Hanna Images of the software environment and the output are on the right. |
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| Generative components screen shot | The output from Generative Components | |
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| Another screen shot of the output from Generative Components | ||
| 06_05_06 I've just finished a prototype of the grid. It's at 1 to 3.73 scale because of the plastic I had available. The actual grid will be 667mm square at the base, fanning out to over a metre. I am waiting on some polypropylene samples from GCIP to test on the laser cutter before deciding what material to use for the final grid |
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| A photo taken part of the way through assembliing the grid. | Polypropylene allows enough flexibility to put the grid together and allow for the curvature of the elements once assembled. | |
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| Sunlight through the grid. The effect is very similar to the animations from 28_04_06 | A view through the top of the grid | |
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| Another view through the top of the grid | The shading effect | |
| 09_05_06 After testing the polypropylene samples on the laser cutter I've decided not to use it as the fumes where too noxious. The material was also too rigid and had a shiney finish which didn't tone down well when it was sand blasted. I've opted for aircraft ply, 0.8mm thick. This material, though more expensive is better environmentally, bends effectively and has a wonderful finish. I've begun to test the making of the prism array. Images of the prism holder and prisms are on the right. The prism holder is designed to hold each prism at the correct orientation to the grid above. (The working for this orientation can be found in the research section 'making'.) The holder is created by taking two sections through each row of the aligned prisms and laser cutting the inverse of the section in sheet materal. The prisms are held between these two 'inverse sections'. A screen-shot of the prism holder is the top left image on the right. Making the prisms First the prism shapes are cut from 20mm thick clear acrlic on the band-saw. The shapes are then sanded to a smooth finish before being polished on the buffing wheel. Each prism takes approximately twelve minutes from start to finsh. I want to create 529 prisms, so thats 106 hours. |
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| Screen shot of the prism holder | Photo of the prism holder test | |
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| Photo of the prism holder test | Photo of the prism holder test | |
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| Gratuitous photo of the prisms | Another gratuitous photo of the prisms | |
| 12_05_06 The process of making the prisms continues. I've begun cutting the final version of the grid in 0.8mm aeroply.
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| Guides for cutting the prisms in 20mm acrylic | 0.8mm Aeroply | |
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| Cutting the prisms | The full size, laser-cut grid panels | |
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| 110 prisms | Some dispersion through the prisms | |
| 17_05_06 The grid is almost finished with just some tweaking to do. The first row of the prism array has been assembled.
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| A row of the prism array for the 22nd December. | A row of the prism array for the 22nd December. | |
