Introduction: [computational Fabrication] Generative Design in Fusion 360: 3D Printing a Chair

OVERVIEW

The goal of this project is to explore possibilities with generative design using Autodesk Fusion 360. The project is inspired by the Elbo chair (https://www.wired.com/2016/10/elbo-chair-autodesk-algorithm/).

This is the fifth project for a course I’m taking this quarter (Spring 2020) on computational fabrication taught by Prof. Jennifer Jacobs at the Media, Arts & Technology program at the University of California Santa Barbara. The idea behind the course is that digital fabrication can be combined with computational design to create complex and functional physical forms.

Tools I used for this work include

• Fusion360, CAD/CAM software by Autodesk
• Ultimaker CURA, an open source 3D printer slicing application
• Creality Ender 3D Pro, a commercially available 3D printer supplied by UCSB

Step 1: STEP ONE [Intro to Fusion 360]

I’ve never used Fusion 360 before so I wanted to complete a small tutorial to get more familiar with the tool. I followed the following tutorial by Product Design Online to create reusable 3d printable stamps:

Fusion 360 Tutorial for Absolute Beginners (2020) https://www.youtube.com/watch?v=qvrHuaHhqHI

I’ve attached an image of my outcomes. I used an old Aten inspired svg sketch. I’m not sure if I’ll print this but it was a great intro to Fusion 360.

The same creator has great resources on generative design. You can access them here:

https://productdesignonline.com/29

This video is a walkthrough of creating a chair with generative design:

The project is inspired by the beautiful Elbo chair that was created out of adjoined CNC milled parts. You can read more about it here:

https://www.wired.com/2016/10/elbo-chair-autodesk...

I’ll be using additive fabrication (3d printing) to print out a scaled down version of my result.

Step 3: STEP THREE [Generative Design for Chairs]

I created two starting geometries for chair designs after googling standard heights and seat sizes. Then I used the Edit Model option in the Generative Design section of each project to create obstacle geometry. I defined some simplified forces on the seat and back rests.

The first outcomes I generated used the default aluminum metal and plastic. I selected Additive manufacturing (since I would be 3d printing the result) and this gave me some weird outcomes that registered as converged but looked quite unfinished.

You can see some of the results that looked like dripped paint. I selected one to halve and mirror to create a symmetric outcome to create my first result (the Rorschach chair) for the patterning on the base.

I repeated the same process for my second geometry and also added CNC milling to the manufacturing style and two new materials stainless steel and cobalt chrome. I had some unfinished outcomes but some that also converged after around 50 iterations to a pleasing result. One observation was that I’d like to mix and match parts… for instance, I got a really cool base on one chair but liked the seat and back frame on another… however this would compromise the structural integrity of the design. It would be great to have a tool that allows for edits and visualizing the impact on how the object handles forces. Overall I think generative design is so powerful -- I can specify approximate forces and create structures that can handle those loads and constraints without needing to verify them myself. If I had time I'd like to use this to build ledges for birds nests (we have several on structures outside the house like protruding lamps).

I selected the final model to print.

Step 4: STEP FOUR [Printing the Chair]

Printing my final design was challenging! I used Cura to scale down the chair but it has complicated overhangs and also I had trouble figuring out bed adhesion. Even though I was using a raft the orientation of the chair was not quite flat and depended on these printed dots. The wood filament I was experimenting with also seemed to be exacerbating the issue so I switched to a transparent filament.

Eventually I added support but decreased the support density so that separating it from the chair would hopefully minimize damage to the final outcome. My print took around 8 hours to complete.

I’m so happy with the result! I think it’s the best looking chair I’ve ever seen. I’m looking forward to playing around with some forced perspective shots later.