On a morning this weekend, while hanging out at home with my coffee in my hand, I decided to play with Fusion 360. I had a part picked out that looked simple enough.
![](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiquLhL7XFxhBTBeGdTeilFFqPMO-i8NJeOd2L25rH5afk6GNhrK_VLLcYaBAEoN4tDUARoGoIYVModcwWkYedzgy1Hm12ALIXx0SKbY_gwv4lqgvJbt5OgmpC5yG-hqkgJumbPew/s400/Screen+Shot+3.png) |
The finished part. It looks simple, but it hides a suprise |
The part I chose looked to be a simple sheet metal part. It looked to be a simple enough part, but it did have a
joggle in it that complicates things a bit.
![](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjMdLQ1_OeDkns-AjZ40IVa1h0VK1NJ-efio4o9DXiZ5FMLYOwgUoQVvb3PgRx9TlyChk_JAilZB8tqH1lqJjFTwj-YhilnOeODAUvyMKqeGe0JGVn4TyWNSpkwJvcfoWXN49K6jg/s400/Joggle.png) |
The joggle that changed how this part was made |
Since it's got this joggle, it can't be easily modeled using sheet metal tools.
![](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiUAks2JsFdFze5jK99NEQe8z7gfejBRozFSFwOs3KdIX1UthDRYQRK3xeK6Mc-ionuOK5X3SdNVsynu3pcBAgP9jvAwz92gJbP0s2ABGL5rjvWSAmv1ItkbjHiJGEF9tLGHAZ1nw/s400/Sheet+metal+attempt.png) |
The sheet metal version wasn't quite what I was after. |
So I decided to model it using the "regular" modeling tools.
I also decided I'd document how I did it here, for both posterity's sake, and in the hopes that it might give another struggling user an idea. I won't go through every single step, but I will give an overview that hopefully encompasses the high points.
The first thing I did was model the envelope. I nothing more than an extruded rectangle. A "brick".
![](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhYdHsk_OJxSHBbUbeexreCNOcL3Dl9vTYE3blTgsGHeHtb8c0uBP2Q7JeLrjZTDZNzH57RD7pxeACs0Kf-qO3Sn1CY2I5QztkjwEp6mAHEuIFdENXTcjEORgLbj2CyZetvKFsArg/s400/Brick.png) |
The starting point. An extruded rectangle representing the parts outer dimensions. |
Next came the process of carving out the shape. I started with the joggle.
![](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEia7GzYtasvZleCOeyOTpsS9Ql7NrmfFTPq-WHX9Mcsjar8rTmYR4NBhE_QlOTQ0cR9RwwAS-vGCTyxzx-Q7n0G7JMj0qBuZDOr69DXvHmB5GUReF2aTG_LtKZ1mm704KzZnOuZCg/s400/Joggle+Sketch.png) |
The joggles cut into the part. I've turned one of the sketches on to make it more visible. |
Once the joggle was in, it was a matter of adding the remaining features, including the outside fillets that represent the outer bend radius. Notice that the part is still a brick. It's just a brick with some nice looking features!
![](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjpxTn6Y6UjGtTQnlgzblE9qWIwJbuhNVF5nTCyGhO9SSE0UIGr4jjqvBcg4vhbfvFLJoxAimYqmCxWbe7_vju50dANYk0E0CzcHfqacMEyFg6-puEwipYASILkmevUAYx9F9YO-g/s400/Nice+Brick.png) |
The brick has all the features of the sheet metal part now. |
This is where my original plan went wrong. My plan was to use the shell command to create the inner profile.
But for some reason, I couldn't select the surfaces I wanted. I always ended up selecting a surface I didn't want.
So it was time for plan "B". I switched to the surfacing workbench and used delete face to remove all the faces except those that represented the outer profile of the part.
![](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEh8jySvmM_94WXL7HqpnbwzslxrSS_aOuK3XIHYvB6hhFuVJEZaIbK72UjoQ0DZt5dbYL6ZYN_z1l9QeN_roFWLv1XomoOgHF7UGzQXHoGlE0rc3hVf8pHAQ8FIqvjM41ue1fJ-8g/s400/Surfaces.png) |
The part with all but the outer profile removed. |
Now that I had only this surface, I was able to return to the solid workbench and use the thicken tool to get the final shape I needed.
In Conclusion
So is this the only way to do it? I doubt it. But it did get the result I was after in a way I was happy with. I'm sure someone out there has a different way of doing it, they may prefer it. And maybe someone out there has a way that's truly better. I would be thrilled if they do and I hope they share it!
How would this part be made in real life?
This is one place that I'm not an absolute expert, so I encourage others to chime in. But I do have some experience making sheet metal this way.
In production, a blank would be placed in a die, possibly using two of the holes to locate the part. Then a press would push the two die halves together, forming the part in one operation.
Here's a pretty good video on this process used for the ribs on an aircraft wing.
If the part is made in low production, A form block can be used, made out of wood or metal. The blank is then formed using a hammer.
He's a video on that process. While this video shows the process being done for steel, aluminum would be done in a similar manner.
The part I modeled in Fusion 360 calls for 24ST aluminum, which is the equivalent of 2024-T3. I know that 2024-T3 can crack when formed around tight bends, so it's possible they would have used 2024-0 (dead soft) and heat treated to the -T3 condition afterward. But that's one place I'd have to defer to the sheet metal experts, feel free to chime in!
And that's it, I hope this video was informative!
A Final Addendum, Murphy's Law Strikes!
As I finished up this post, I tried the shell one more time. Guess what! It worked! It seems I was just not quite getting the picks and clicks right when I tried it earlier. But I decided to go ahead and share the post anyway because I still feel it's a viable alternative.
![](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjkXAq2uRQztDkoAOHa812tT5XDrsglisYAWrieQQwirFgYwX7ciG1tkpurgARvWpbjcywCRo3PABDkZUf6RCFyQEBL9-BF5m6YeEfCm3xLwTRKuKLGX0BshAZXVmmTuQymiIXT2A/s400/Shell+works.png) |
It figures! The shell does work! |