Final Development¶

Workflow¶

Now I'll go step by step as I got clarity about how my workflow has to be to be able to develop my first prototype that I made in TPU and also the final result in Balena Filaflex.

3D Scan¶

This as my first step, I talked to one of the interns, she super sweetly offered to be one of my models so she was the first person that I scanned, some tips to scan properly:

Start at the front and then go to the sides
Go super slow
If the breasts are large, take two scans: one with their favorite bra on, and one without a bra
Be especially careful around the breast area, as it has a double-curvature shape
Don't forget about the back as it helps with the straps size

I don't have any pictures or videos of the procedure in order to protect the intimacy of the models and help them feel more comfortable

But here you can see the results:

Clo 3D¶

This as my second step, It was very important to me to get a previsualization of what the bra should be and how it'd look like with the auxetic pattern and also get the pieces of the traditional sewing pattern for it to be my guide in Rhinoceros as the next step.

Below you can find my CLO 3D file. I must say I wasn't expecting to do this animation and such a nice preview of my project but thanks to my local mentor Petra who helped me and taught me how to do it, she pushed me to do this and I must say the outcome is very nice, and also thanks to her I get to share a digital version of the bra.

📦 Download CLO 3D file Click Here

Grasshopper File¶

After trying the python code (shown in the second stage prototyping) I decided that all the corrections that needed to be would takke too long and as I was in a rush to finally get my first complete prototype I decided to go another and more simple way. I dedicated a whole week to define my grasshopper script to get some clarity around which parameter I'd be able to control so below you can see and download my script:

Remember you can click in the pictures to zoom in

Here I take you step by step pf my GH script and show you what each part does, at the bottom you'll find the downloadable files⬇⬇⬇

This first part is the scrip for the cup part

This part is for the straps lenght and size scaling

Rhino & Grasshopper Results¶

Auxetic Pattern Research¶

Research Papers Auxetics

Auxetic materials behave in a counterintuitive way: when stretched, they become thicker perpendicular to the applied force. This unique property is due to their internal geometry, not their material composition. Inspired by this phenomenon, I explored 2D auxetic patterns that could later conform to 3D anatomical surfaces through the force applied by breast's weeight and shape.

Pattern Design & Geometry

The core pattern I chose is based on rotating units, specifically diamonds and triangles, which can open or close when stretched. This gives flexibility and directional expansion.

I used Grasshopper in Rhino 8 to develop parametric patterns, defining:

Theta (θ): the rotation angle of units

t: the thickness of the connecting material

At first it was quiet hard to understand this concept but after watching this video twice I finally understood the basics of auxetics!!!

LINES THICKNESS

This parameter defines how thick I want the lines of the auxetics to be which had to be increased to the maximun because when 3d printing a thin line doesn't print properly.

MOTION

This is only for previsualization purposes, how the pattern would look fully deployed.

SHAPE

The shape can be modified to make it more or less stretchy.

CREDITS

Before continuing with the design process I wanted to be sure that the auxetic pattern works, so I ran a first test of three different patterns and you can see how happy I was when I saw it working 😊

Connections¶

Profiles for 3D Printing with Balena¶

The printer I used was an Elegoo Neptune 4 Max

Bed plate: 420 x 420 mm
Nozzle Size: 0.6 mm

Here You can check all the profiles I used in Ultimaker Cura to 3D Print with Balena

Some tips here:

Max speed of 15mm/s
Clean the nozzle after every print
Bigger nozzle size, less probability of nozzle clogging but at the same time less amount of details
No retraction
Release the gear tension almost completely

It works!!!