Design informatics | Fleximolding acoustically optimized backstage

Technical Narrative Technoledge Design Informatics Ammar Taher 4745639 MSc Building Technology Faculty of Architecture and Built Environment TU Delft

• Introduction • Scriptting

Just start!

Production script approving

CONTENT

• Fabrication

Technique

get to know... developing

fleximolding

Materials

What do we have?

Casting process

Testing the material

• Conclusion

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While the new digital fabrication technologies are finding its way to the architecture profession, the knowledge about these technologies is not anymore enough. Application and hands on to get the utmost of these techniques - to help develop and optimize our designs as architects - was my main goal during technoledge design informatics course. For ten weeks we went through the process of “from design to reality�. Learning how we can use computational tools like Grasshopper, Rhino, and their plugins to help us in our design process as well as materializing into reality.

INTRODUCTION

Designing an acoustically optimized stage was the main design problem for the course, through which we explored the fabrication process. Fiberglass and honeycomb as materials, and fleximolding as a production technique, these were the main constraints for the process within a certain scale of the stage.

First two weeks were small groups of two conceptualizing the stage and presenting each week to the rest of the class in a feedback helpful environment. in parallel grasshopper workshops were tutored by the teachers to help refresh the scripting skills.

After choosing the concept that the class will go on to develop and build we were divided in bigger but sub-group with a different task for each. Management, form, acoustics, structure, assembly, and materials, these were the groups that cooperated together. Being part of the materials group I had the opportunity to get hands on the materials assigned, while also maintaining the grasshopper scripting for the molding process.

On our agenda as a group, we had 3 main tasks to explore, scripting for the fleximolding process while also approving the script used for the building weeks. Secondly, materials casting process practicing while also performing some tests on the material that might help other groups. Lastly the fleximold as a process and as a technique how it is used and how we could improve it.

These three main agenda tasks are what is gonna be more detailed in the next pages with some diagrams that help document the process that we went through and helped me develop a more in-depth perspective about the digital fabrication process.

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SCRIPTING

JUST START!

Starting by scripting we had two main tasks to achieve. Firstly, assuring that the panels made by the form group are producible on the fleximold, we had to work on curvature check definition. The final script was used by the form group defines for each panel if it has more curvature value than the actual fleximold matt.

Secondly, producing the pins height for each panel. we started from where our colleagues ended up in the home assignments and developed many times.

Considering the inputs for the script as full shell panels we were confused and complicated the definitions at the beginning. which we further developed after.

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The following diagram shows the definition main points which are applied to each panel individually.

PRODUCTION SCRIPT

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• We developed a script that also sorts all the panels in a list according to their required pins heights adjustment, which reduces the time needed during the building week. this might be further developed if it could be integrated after developing the final definition of a single panel into multiple panels.

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4 1 inputs/ parameters

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2 orientation 3 pins heights 4 labelling into text 5 XY coordinates of corners

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6 resin & hardener amount 7 curvature check

APPROVING

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To ensure that the script is working properly we 3d printed the shells in 1:20 scale model. Also created a mini fleximold to test each panel before production. This approved the script finally after several trials.

TECHNIQUE Fleximold is a table molding technique which allows the production of a double curved surface. the fleximold is a 1 * 1 m table held on 4 legs, 49 steel rods in a square grid of 7 * 7 cells. the pins hold a plastic matt that is CNCed in a 50*50 squares grid which represents the molding surface. the pins heights are produced in grasshopper script that produce the heights for each different panel.

Adjusting the pins heights represents points on the molded surface adjusts the shape of the matt after stretching it using ropes. The ropes are hooked and tightend enough to keep the shape of the surface so that the process of the molding can start.

GET TO KNOW....

As the group didn’t have any previous experience with the fleximold we had to discover how it works. We wanted to make sure that the design the form group is working on is feasible enough to be produced in a one week time in Poland. Main points we were looking for during our practice on the mold in BK TU Delft before we go to Poland are: • Timing the process starting from pins heights adjusting, and getting to figure out how its related to the script measurement. We decided that it should be from the bottom of the table. We got to know also some errors in the script regarding this measurment method.

• Matt shaping using ropes, and the curvature check and matching between the script curvature value and the actual value of the matt.

• Mold borders fixing on the matt and decided to use tapping on the plastic rolls as an easy fast solution during the production week.

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While we were exploring the fleximold technique we also had a brainstorming session for some development ideas to ease the process. We decided to use a ruler system that defines the coordinates of each panel to be oriented on the fleximold. We made a prototype of the ruler at BK of which we managed to send the drawings to prepare two it in Poland before we go.

Inspired by the fleximold in Civil engineering faculty at TU Delft we also suggest using magnets instead of the ropes to make it easier to adjust the flexi for each panel and save time. After trying by some magnets we found out it requires really strong magnets which will be costly for two fleximolds with 49 pin each.

DEVELOPMENT • Another idea of using stepper motors and Arduino board to control the pins was proposed but due to the time constraints we couldn’t investigate it more but it would be a recommendation for further development. • During building weeks the hooks used were not strong enough which required some improvising to change into a different type of screws and fixing rope. Rope type and material affect the quality of shaping the matt and controlling it. While also choosing the right rope ensures longer lifespan due to multiple tighten and untighten times.

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FLEXIMOLDING

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The following diagram shows the process of fleximolding. it also mentions some tips realized while working on the process at BK and Poland.

MATERIAL Fiberglass was the main material that we explored. We were able to find a proper ratio of the resin amount used for each panel in relation to the surface area. 0.75 of the area should be in liters the resin amount to cast a panel with 3 layers of fiberglass. The hardener for resin ratio is 2-3 % for polyester resin.

Dealing with dangerous materials in respect of inhaling and skin contact we had to put some safety tips to be used by the other teams who didn’t experience the material before building weeks.

WHAT DO WE HAVE?

Honeycomb had to be investigated later after knowing how to cast the resin and fibers. We continued over the research the smaller groups did during the first two weeks about the visual and acoustical possibilities the honeycomb could be integrated with.

• Using bio-resin was tested and the resin to area ratio is 50%. Bio-resin has many potentials as sustainability, less harmful material to skin and inhaling. While unfortunately its also more costly and the curing time was much longer which didn’t fit with the building week schedule.

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MATERIAL CASTING

The following diagram shows the casting process. it also mentions some tips realized while working on the process at BK and Poland. • mentioned timing and ratio are for the Polyster resin which differes for Bio-resin.

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MATERIAL TESTING

We performed compression strength test which the structure group used its result as a reference for their design. a test for cubic samples of different layers and composites with honeycomb or only resin.

Other samples of smooth and rough surfaces with different layers were used by the acoustics team to know more about the acoustical performance of the material.

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Mentioned in this narrative report a quick shot about what I have learned in a digital fabrication process within my team. each aspect mentioned is an agenda task that we investigated in detail which the words were not enough to mention but the diagrams might help to conclude the process mentioned as well.

The collaboration between different aspects and groups working together in a computational environment highlighted the importance of open source platforms. as the scripts we did in our group wouldn’t have been without the use of others scripts during homework assignments, and the whole scripts in all the groups wouldn’t have been without the open source plugins for Grasshopper online.

CONCLUSION

If I had the chance to do the course again I would integrate more with the groups working in-depth into their work results and tools, for example exploring more how the assembly group nested the borders in the minimum amount of boards as possible, or what the results of the acoustic test represented and how its conducted. even more, I would let myself discover the material further than the constrained materials in the course as this might inspire more solutions for the whole team.

I would also ask for more feedback from the tutors for details regarding scripting especially and their insights on that, as different approaches to work help create the optimal solution at the end.

Finally, the digital fabrication process might have enabled us as architects and designer to create and imagine more freely as it eased the production techniques. while on the other hand, it requires a lot of management for the interaction among different groups. behind screens, also the production on site affects the process and the precision of the execution might completely change the result if not well controlled and designed.

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