Teaching Fellow: Dan Tish
SCI 6338 | Introduction to Computational Design | Final
Harvard Graduate School of Design | Fall 2019
ABSTRACT
This group’s work (including Sana Sharma and Katarina Richter-Lunn) was motived by the study of sound. Each member researched a different facet. In addition to working with sound, each group member found ways to manipulate the inputted sound. For this portion amplitude was used as a means to analysis un-paralleled layers in Fused Deposition Modeling. The original sound was printed by a LulzBot Mini 2 3D printer. The sounds it made while printing were then recorded. This information was processed into an additional 3D print to create the printer’s response to the inputted sound. 
WORKFLOW
The process began in P5.js (a Java Script library for coding) where the amplitude values of a MP3 (coding format for digital audio) file were recorded to a Tab Separated Value (TSV) file.  These sampled amplitudes were used to alter the Z heights of a series of planar circles in Grasshopper3D.
INITIAL DESIGN TESTS
The first 3D prints were generated from Perlin and Sine graphs. These prints were not only modified to have un-paralleled layers but in addition have a parabolic side profile. Difficulties with layer adhesion required that the curved profile be removed. The change limited the variables allowing for the focus to be on the extrusion settings as they related to the un-paralleled layers.
SINGLE EXTRUSION MULTIPLIER
These tests used a single extrusion multiplier ranging from 0.01 to 0.05. The initial prints used the 0.05 extrusion rate which resulted in clumping due to the excessive material deposited. This occurred as the compression on the layers increased due to the un-paralleled nature of the design. The 0.01 extrusion rate did not deposit sufficient material for the print to adhere to the build plate. In addition, an extrusion rate of 0.03 was tested. Although this remedied some of the prior issues, it was evident that this rate would need to be modified based on the distance between the layers.
VARIABLE EXTRUSION MULTIPLIER
A function was developed in C# that allows for the extrusion rate to vary depending on the distance of the next layer relative to each printed coordinate. As the layers are more compressed the extrusion multiplier is lowered the inverse is true for those layers that are less compressed. This is relative to the approximate height of each layer. The photos below denote the iterative tests of a range of extrusion multipliers utilizing the inputted polyline.
DESIGN ONE
Juice- Lizzo
Lizzo’s music has great variability in volume thus creating more dynamic amplitude data. Resulting in a more complex design.
For this test the sample rate was increased from 100 to 2500 values. At the scale and resolution, the fidelity of the print part is not comparable to the vector drawing. While the amplitude of the song juice was printed. The 3D printer was recorded. It would seem that the recorder needs to be closer to the printer so that the values are more evident. As a result of the less extreme values the fidelity of the print was improved.
Cry Baby- Lizzo
DESIGN TWO
Let It Be- The Beatles
To increase the number of people who could relate to the music The Beatles song, “Let It Be,” was chosen. In addition to its ubiquity, it has a slow tempo with minimal amplitude.
The printer’s accuracy and the small size of the print made denoting a songs entire amplitude as a single top layer not achievable with a great level of fidelity. As a result, the data was divided into five groups with approximately three-hundred twenty amplitude values. This divided the amplitudes into thirty second intervals. This was continued throughout the final two iterations.
The LulzBot Mini 2 demonstrate the correlation between the printer’s noise and the lack of variability in the amplitude.
VIDEO OF THE LULZBOT MINI 2 PRINTING LET IT BE BY THE BEATLES
SMELLS LIKE TEEN SPIRIT- NIRVANA
Further range was added to the prior genres by using the song “Smells Like Teen Spirit” by Nirvana. This song has a mid-range of amplitude variability. Starting off slow and ramping at the end of the song.​​​​​​​
The LulzBot Mini 2 demonstrate the correlation between the printer’s noise and the change of the amplitude.
VIDEO OF THE LULZBOT MINI 2 PRINTING SMELLS LIKE TEEN SPIRIT BY NIRVANA
ROLLING IN THE DEEP- ADELE
Adele’s “Rolling in the Deep” was chosen for its consistent variability as it progresses through the song. Her ability to crescendo and decrescendo regularly throughout the song creates a dynamic pattern for the toolpath. 
The variability from the 3D print was reflected in the LulzBot Mini 2’s interpretation.
VIDEO OF THE LULZBOT MINI 2 PRINTING ROLLING IN THE DEEP BY ADELE
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