![](https://i0.wp.com/www.paulotrentin.com.br/wp-content/uploads/2023/07/image-1.png?resize=740%2C414&ssl=1)
Hi, today I’ll share the differential I build using Fusion 360. This is an important piece for my retro excavator since it should be the hardest one to draw.
Here’s a general overview of the differential working:
Below you can see the video where I show the pieces and how I did them:
And Here are some photos:
![](https://i0.wp.com/www.paulotrentin.com.br/wp-content/uploads/2023/07/image.png?resize=760%2C427&ssl=1)
![](https://i0.wp.com/www.paulotrentin.com.br/wp-content/uploads/2022/06/bevel-gears-fusion-360-3d-printing-1.jpg?resize=760%2C442&ssl=1)
![](https://i0.wp.com/www.paulotrentin.com.br/wp-content/uploads/2022/06/image.png?resize=760%2C560&ssl=1)
![](https://i0.wp.com/www.paulotrentin.com.br/wp-content/uploads/2023/07/image-1.png?resize=760%2C427&ssl=1)
Some stress testing
I did a couple of stress testing to ensure my design was good enough for my backhoe project and learn a lot from those tests, for instance, I quickly realized the wall of the inner differential was very thin so I ended up reinforcing it:
![](https://i0.wp.com/www.paulotrentin.com.br/wp-content/uploads/2023/07/PXL_20230628_120728059.PORTRAIT.ORIGINAL.jpg?resize=760%2C1351&ssl=1)
![](https://i0.wp.com/www.paulotrentin.com.br/wp-content/uploads/2023/07/PXL_20230628_115746703.jpg?resize=760%2C428&ssl=1)
![](https://i0.wp.com/www.paulotrentin.com.br/wp-content/uploads/2023/07/PXL_20230630_010428501.PORTRAIT.jpg?resize=760%2C1351&ssl=1)
How I did do my stress tests?
Let’s say they are simple:
There’s a limit for PETG strength of course, and I also wanted to learn where the limit was, and this is the result :)
![](https://i0.wp.com/www.paulotrentin.com.br/wp-content/uploads/2023/07/PXL_20230704_004236169.PORTRAIT.jpg?resize=760%2C428&ssl=1)
Conclusion
This was by far my most complex drawing so far, a lot of learning and excitement. I’m super proud of the result and how much Fusion 360 helped me to achieve it. Now let’s move to the next phase: the front direction system of the retro excavator!