How do I created a rolled, sheet metal cone with an overlapped joint?

[thecivilnassar]

I want to make a sheet metal cone with a small overlap so that it can be glued together. I don't have any screenshots or reference photos, so I'll try to explain. 

Let's say that I want to make a sheet metal cone in the sheet metal environment that is open on either side. The top is 25 mm across and the bottom is 50 mm across. The metal continues in a smooth curve from beginning to end, so the joint is not raised before overlapping. Almost like a spiral. This joint would overlap the beginning by 3mm. Then a flat pattern can be made.  

[barry9UDQ6]

I think that in order to do this you would need a lofted flange between 2 splines. Unfortunately something Fusion is not capable of doing in the SM environment.

This is a feature I personally have a need for, hopefully 1 day..

[TheCADWhisperer]

Can you File>Export your *.f3d file to your local drive and then Attach it here to a Reply?

[barry9UDQ6]

If this sort of geometry could be unfolded in Fusion, my workflow would be so much simpler.

[thecivilnassar]

I have no file because I have no idea where to even start with this!

[barry9UDQ6]

No worries, I did it for you!

Pretty quickly but it's there. The only problem is that Fusion can't flat pattern it.

I included another lofted flange in the model as well, as another example of what Fusion can't flat pattern (although Inventor can)

See my post above yours for the model.

[etfrench]

You left out the height of your (truncated cone) 😀  There are quite a few online calculators for creating a pattern for a truncated cone, but the height is required.

Here's what it should look like in Fusion 360:

[thecivilnassar]

Thanks for making that for me. I understand now. So, I would be able to make the flat pattern in Inventor? My intended purpose is to make this as a Cricut cut file.

[thecivilnassar]

That's exactly the kind of pattern I want to make. I wanted to make it as a 3D model first in order to take into consideration the thickness of the material and the base dimensions. This is definitely helpful though, so thank you!

[KristianLaholm]

There is a possibility to approximate the cone with 2 arcs and a short line, the short line is needed for sheet metal.
The body is created using 2 Surface Extrude with taper angle, the angle is calculated with parameters.
Changing dimension of the cone needs to be done from "Change Parameters" dialog box.

The k-factor in Sheet Metal rules is set to 1, this maintains the dimensions from 3D-model to flat pattern like the materials is stiff and has no flex/give.

[etfrench]

Make the 3d model first using the revolve command, then use the dimensions to create the flat pattern.

[meisterpumpernickel]

Hi Kristian,

thank you for your post. It helped me a lot. 

But i am still having trouble when I flatten. 

Do you or anybody else have an idea what the problem is?

[KristianLaholm]

Your first sketch is not fully defined (Constrains and Dimensions) and have a warning "Sketch Plane lost".

You need to start over with that sketch.

What is the design intent? A cone with radius 290mm and and angle of 47,7deg?

[meisterpumpernickel]

The design intend is to have a cone with the bigger radius being 290mm and the smaller radius being 235mm with an height of 50 mm. I think that equals a 47,7deg.

Im quite new to fusion. So im not sure how to fully define the Constrains and Dimensions. But ill try again.

Thank you!

[Ex_Machina_Engineering]

Take a look at this. If you don't know how to take it from here, let me know and I can help you a bit. Dimensions are arbitrary. Use this as a methodology guide, not your actual model.

[meisterpumpernickel]

Thank you so much. I think i get it now how the dimension setting works. I will play around. 🙂

[TheCADWhisperer]

@meisterpumpernickel 

Do as surface body and then Unwrap in MeshMixer.

[meisterpumpernickel]

Thank you! That is a great tip. Is there a possibility that I could look into the file, you made the screenshot of? I think i could learn from the constrains you set. (especially how you defined the angle of the overlap)

[TheCADWhisperer]

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@meisterpumpernickel wrote:
 Is there a possibility that I could look into the file...

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@meisterpumpernickel 

I simply used the dimensions that you provided in previous reply along with the file that you attached to try to decipher the Design Intent (see Attached *.f3d file).

I used 1.6 offset rather than the Thickness value of 1.5 so that the faces would not merge if this surface was Thickened.  All dimensions should be editable within logical limits and update.

[mohdsalman1]