Fusion 360 Topology (Shape) Optimized 3D Printed Bracket for Raspberry Pi Touch Screen

In this Instructable, I will use Fusion 360 (which is free to makers, students and educators) to design and topologically optimize a bracket which will mount my raspberry pi touch screen to a wall. Topology optimization is an algorithm that adds and removes material in a design space to create a strong and lightweight objects. Material is added where stress is high and removes material where stress is low. This creates a part that has a high strength to weight ratio. Additionally topology optimization is being to be used quite commonly in industry to design machine components that are Strong but light, for applications such as aerospace. While this process makes strong and lightweight parts, the designs can be very hard to manufacture due to complex geometry. However, 3D printing has the ability to produce almost any geometry has, add is a great option to produce topology optimized parts. In this instructable, I topology optimize a bracket to mount a raspberry pi touch screen, however this is more generally a guide to go from nothing to a 3D printed topology optimized part or bracket.

• Fusion 360 (free to students, educators, and makers/hobbyists)
• 3D printer (of you dont have a 3D printer, you could have your bracket printer by a company but that can be expensive)
• 8 - M3 bolts
• 4 - M3 nuts
• Raspberry pi official touch screen

The specific bracket I designed is for the Raspberry Pi touch screen so I got dimensions for the mounting points of the screen and decided where I wanted it to mount onto the wall. Based on these dimensions I designed the bracket, or the volume that would be the bracket design space. I'm not going to cover how to design a part in this tutorial as there are many good tutorials out there. This tutorial will cover how to set up, run and print a topology optimization study using Fusion 360. The part to be optimized, shown in the images, is a bracket to mount a raspberry pi touch screen to a wall.

With the part we want to topology optimize now designed, we can enter the simulation workspace of Fusion 360. You can enter the simulation workspace through the drop down menu on the upper left of Fusion 360. Once in the simulation workspace a menu should pop open to select the type of simulation to run. If the menu does not pop up select the new study option and it will pop open. From this window select the shape optimization study. The new simulation study will open and the part you want to optimize will be displayed in the workspace.

In the simulation work space you can now add Constraints, which are the points that are fixed to the wall in this case, and Loads, in this case the weight of the raspberry pi. If you are running a topology optimization for a different part you will want to think carefully about how the bracket will be used to set the these values.

Witht he loads and constraints we added in the previous step, the simulation is technically ready to run, however, to get the best possible results we will want to first preserver geometry of our model. In this case I have presevered an volume around the screw holes, this will make sure there is a goo hole of the screw and plenty of area to tighten the screw and nut against the wall and screen. Next, we want to reduce the size of the mesh we are running because the finer the mesh the better results we will get. However, a finer mesh also means the simulation will take longer to run, so if your simulation is taking longer then you want you could adjust the mesh.

With the simulation set up the way you want you can now go to solve the simulation. Once you click solve a new page will open that shows you studies that are ready to be solve, make sure your study is selected and click solve. now the simulation monitor screen will pop up and you will be able to monitor the progress of your simulation. Once the simulation is complete you can click results and look at your simulation results. On the right side of the screen there will be a slider bar where you can adjust the mass of your component. Adjust this bar until you are happy with the results.

Now that the Design is as you want it you will want to promote it to the design space (Result Tools>Promote). In the pop up menu, select "Design Workspace" for the "add mesh object to" option and hit OK. You will now be back in the design workspace, but now the optimized geometry will be there in addition to the original geometry. (click the eye next to body one on the left middle of the screen to hide the original geometry). Now, if you want to smooth the part as I did you need to remove Capture the Design history, as shown in the figure, this will make the mesh tab show up in the top menu. Go into the mesh>modify>smooth to smooth the part. While smoothing the part isn't needed I think it makes it look much better.

Now that you have the optimized geometry smoothed you are going to want to save it as an STL file and print it. To save the STL, right click on the mesh boy on the left side of the screen and click "save as STL". With the part saved as an STL you can take it to any slicing software and prepare it to print on your 3D printer. If you don't have a 3D printer, I bet you can find someone you now with one to print your bracket!

Now that you have designed and printed some super sweet brackets, hang them up for the world to see!! In this case if you are also working with a raspberry pi touchscreen the mounting threads are M3.

Thanks for looking, hope this is helpful!