Vacuum Formed Masks Methodology Report

UNIVERSITY CO-OP

Materials Lab p

Vacuum Formed Mask Workshop

Vacuum Formed Mask Workshop Introduction 3D Scanning

3D Software CNC Routing Vacuum Forming Conclusions

Introduction

Reseachers: Jody Broccoli-Hickey and Kara Holekamp Course: Materials Lab Research Instructor: Jen Wong Semester: Fall 2016

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Objective: The Vacuum Formed Mask Workshop put on by the Materials Lab was meant to introduce students to an underutilized piece of equipment at The University of Texas School of Architecture. Students were able to participate in the workshop and gain hands on experience with the vacuum former, using a 3D mask form provided by the Materials Lab and a sheet of plastic.

The mask forms were fabricated using the 3D scanner to capture faculty member’s faces. The 3D scanner produced a digital model that was then sent to the CNC router to be cut out of MDF boards.

There were many variables in this process, from the creation of the 3D digital files to the materials used for the vacuum former. This report documents those variables for future students interested in a similar process.

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3D Scanning

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3D Scanning

Equipment The UTSOA has a Konica Minolta Vivid 910 3D non-contact digitizing system. This scanner is located in the digital fabrication section of the technology lab in Sutton Hall 1.102 and is free for use by all students in the School of Architecture.

The Vivid 910 system is capable of scanning over 300,000 data points with very high accuracy in under one minute. The unit is also equipped with an automated rotary stage for 360 degree captures and will overlay captured geometry with textures captured from the camera lens of the unit.

Instructions 1. Turn on the Konica Minolta Vivid 910 3D scanner on before the computer.

2. Launch Geomagic Studio 2012.

3. When the program opens, select new “Scan”.

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3D Scanning 4. The Minolta Vivid camera should show up at the top of the screen. If it doesn’t you can find it under the Hardware tab.

5. Click the camera button.

6. There are three different types of scans: Single - Takes a single scan from one angle.

Continuous – After the first scan, which will require confirmation, the scanner will automatically continue scanning, rotating the object by the number of degrees specified in the Step box between each scan.

Multishot – Like Continuous mode, but requires you to click ‘Scan’ after each step.

7. ‘Live Image Display’ allows you to see what the camera will capture. Turn off streaming if the program is running slow. Click ‘update’ to take a snapshot. You will hear the camera take a quick scan and then display what is in the viewport.

8. Under ‘Scanning Options’, click ‘Scan’ to capture image. This produces the 3D surface, that you can then edit within the Geomagic software.

For information about additional steps needed to take continuous or multishot scans, please consult the UTSOA wiki page. https://wikis.utexas.edu/display/SOAdigitech/3D+Scanning+Guide 6

3D Scanning

Capture Image For this workshop, we were able to create a 3D surface mesh of faculty member’s faces with a single photo scan. The resulting 3D surface can then be edited to prepare for the CNC router file.

Edit 3D Surface The software associated with the 3D scanner, GeoMagic, allows you to edit the 3D surface and save as multiple file types.

Export .stl File Once an .stl file version of the 3D mesh has been exported this can further be prepped for CNC routing with Rhino and PartWorks 3D applications.

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3D Software

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3D Software Finding the Right Software When attempting to make a 3D surface for the workshop, we explored several softwares that have different approaches to creating 3D forms. Some softwares require the object to be present, while others can stitch together existing photos.

Below are a list of some of the programs we investigated and a short description of their capabilities.

Software

Description

Agisoft

Generates 3D files from photos Photogrammetric process of digital images to generate 3D spatial data

Smoothie 3D

Draw 3D form over photo

Online program, trace over image to produce simple 3D form

123D catch

Scan 3D object

Phone app, requires at least 8 images from different angles

Z-Brush

Digital sculpting

Program used for 3D animation, like an analog clay sculpting process

MudBox

Digital sculpting

Create 3D geometry and textures with digital sculpting

Comments

Similar to 123D catch, but with full desktop support and more options

Autodesk ReMake Scan 3D object

Software Exploration For our workshop, we wanted to create a 3D model of a famous architect using images that we gathered online. This proved to be difficult, since most of the programs required several photos from multiple angles to create a spatial data.

We had the most success using Mudbox to sculpt a likeness of a famous architect, as seen below. We also explored the 123D catch app, using both images we took on our phones, and also submitted multiple images of a famous architect to see if it could stitch the images together.

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3D Software 123D Catch Below are two of the outputs from 123D Catch, using multiple photos that we took on our phone. The image on the left was created with about 20 photos, while the image on the right had about 50 photos. We had no success submitting online photos of a famous architect.

MudBox In an attempt to produce masks of individuals that are not part of the UTSOA or available for 3D scanning, we turned to a digital form of analog sculpting made possible by Autodesk’s MudBox application. As compared to the 3D scanning technique, this process required a large amount of time for completion due to its nature of re-creation by hand. The sculpting shown below of architect Rem KoolHaas required roughly 6 hours of time, but also resulted in a 3D mesh with high levels of detail and freedom for manipulation.

Once completed, the model could be exported as a .obj for CNC prepping in both Rhino and PartWorks 3D.

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CNC Routing

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CNC Routing Choosing a Bit and Producing CNC File After confirming the use of a 1/4” wood bit, we prepared the prepped Rhino file with PartWorks 3D. This final process readies the model into a file type specific to the CNC machine’s software, with values and dimensions specific to your material thickness, the size/type of cutting bit used, and amount of time allowed for the routing process.

Prepping for CNC Routing The completed models, both from 3D scanning and our digital sculpting were compiled into a single model in Rhino in which we could confirm dimensions and necessary slicing that will occur depending on material thickness.

We chose to laminate MDF into 2” thick panels, which then required our masks (at 3 - 3.5” in height) to be composed of two slices. These slices, once routed, would then be glued together to form the final wooden-face form.

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Vacuum Forming

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Vacuum Forming

Material Choices and Process After completed research on potential plastic types, testing was completed on received samples. Each plastic was tested to determine its potential utility for mask making. Some of these characteristics included amount of time to heat the plastic, its strength when formed over the wooden faces, and the quality of detail resulting from the vacuum forming process. After this testing, a select group of plastics were decided upon and are now on hand for the mask-making workshop.

Materials

Description

ABS Extruded Acrylic Cast Acrylic PETG HIPS HDPE LDPE Polycarbonate PVC Polypropylene Styrene

Hard, glossy, tough Softer, more uniform thickness/quality Harder, durable, higher temperature resistance Lightweight, recyclable, strong, transparent Tough, low cost, easy to fabricate High impact and tensile strength, low moisture absorption Flexible, lower density, lower tensile strength High strength, slippery surface Rigid, high strength Lower strength, high impact and tensile strength Low density, low melting temperature 14

Vacuum Forming Results from Vacuum Tests Below are comparisons of each plastic type after different durations of heating in the vacuum former. For each plastic, the first test was a length of two minutes and the second test was either for a shorter or longer amount of time, depending on material response.

For our workshop, we used white styrene, black ABS, and LDPE.

white styrene - 1 minute

white styrene - 2 minutes

black ABS - 2 minutes

black ABS - 3 minutes

LDPE - 1 minute

LDPE - 2 minutes

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Vacuum Forming

cast acrylic - 2 minutes

cast acrylic - 3 minutes

clear PETG - 2 minutes

clear PETG - 3 minutes

clear polycarbonate - 2 minutes

clear polycarbonate - 3 minutes

HDPE - 2 minutes

HDPE - 4 minutes

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Vacuum Forming

white polypropylene - 2 minutes

white polypropylene - 3 minutes

grey PVC - 1 minute

grey PVC - 2 minutes

white acrylic - 2 minutes

white acrylic - 3 minutes

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Conclusion This workshop allowed us to explore several new programs, equipment, and materials in order to produce a final product. As a summary, we want to include some of our personal experience with these tools for future students who may be interested in utilizing a similar process.

UTSOA 3D Scanner and Software: We found this to be the most effective tool for getting real-life human faces into digital form. The tool required no more than five to ten minutes for each individual face, and produced mostly accurate 3D meshes. For improvement, it’s advised to attempt the “multi-shot” option with software. This incorporates multiple images to produce a 3D mesh, and could possibly improve the quality of our models that were completed using the “single scan” option.

3D Software: As an alternative to the 3D scanning hardware and software provided by the UTSOA, Adobe’s 123D Catch was our next best option for capturing 3D meshes from existing objects or people. BUT, it is drastically inferior to the 3D scanning tool used for the majority of our faces. Utilizing a cell phone camera, each facial scan completed with 123D Catch did yield a recognizable mesh, but with obvious deformations that rendered them unusable.

The next best option was a digital sculpting tool. Adobe’s Mudbox allowed us to literally sculpt a human face from reference images. This could produce highly detailed meshes, but required a skilfull and time-intensive process.

In the end, Mudbox may be a better tool for adding detail after using the UTSOA’s 3D scanning hardware and software. It should also be noted that the model detail may not be fully realized depending on the decided physical output.

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Conclusion CNC Routing: CNC routing was effective, but the use of wood was time intensive and adds a level of complexity to preparing the CNC files. Perhaps in the future using foam, as opposed to wood, one could improve both time and detail output. One could produce a negative 3D face shape in foam with high detail, then pour Rockite into the form. This would also reduce the necessity to slice our model and glue the pieces together in the end. The goal here would be to produce a higher amount of detail in each mask, while still reducing fabrication time.

Overall Summary: Despite the workshop’s light and playful nature, it stands as an opportunity to introduce students to less utilized digital fabrication tools and software within the UTSOA. The hope for this is to increase student participation and consideration of unique forms of production in the UTSOA and perhaps to continue to spur innovation in future design thinkers.

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