Unable to convert body to sheet metal

[manzanitacycles]

I've made an elliptical tube in an attempt to turn it into a sheet metal part to print it as a notching template following this YouTube video: https://youtu.be/2w9Kez5U_QU. When I try to convert the body to sheet metal I get the error: "Can't calculate body thickness..."

I've tried making the elliptical tube in a couple of different ways but get the same error. Any idea how to solve this?

[g-andresen]

Hi,

Please share the file.

File > export > save as f3d on local drive  > attach it to the next post.

günther

[manzanitacycles]

The file was attached to the original post.

[jhackney1972]

You have gotten off to a bad start.  Your model seems to have been imported as a dumb solid and cannot be edit effectively.  In the Screencast I show you how to create a quick elliptical sheet metal tube and unfold it.  The 5 degree gap can be decreased once the model has been finished.  The key to unfolding is the small extrusion join to give you a flat area to unfold from.  The model I used in the Screencast is attached.

[manzanitacycles]

Thanks John.

I started the new document by opening a STEP file. The STEP file contains a commercially available oddly shaped conical tube. I need to refer to this cone in order to print out the coping template.

I then created the elliptical tube to approach the cone at a specific angle and location. I then combined the two bodies with the cut command to create the proper cope on the end of the elliptical tube where it intersects with the face of the cone. In the file I included, you can see that one end of the tube has a contoured profile. I then added the split in the tube to get it ready to become sheet metal. When I try to convert it to sheet metal, it throws the "can't calculate body thickness error".

When I do the same steps using the pipe command to create a round tube, it works no problem. In this case though I'm working with an elliptical tube.

Not sure why Fusion can't calculate the body thickness in this case.

[jhackney1972]

As you can see in the Screencast, you must have a very small straight section in order to convert the body to sheet metal.  Yours converts just fine but you cannot unfold it due to the way it has been created.  

[manzanitacycles]

Thanks John. I appreciate your time. I added the straight section and attempted to convert it to sheet metal but I get the same error.

The method in your video doesn't take into account that I have to create the coped profile of the mating tube before flattening the ellipse.

My method works for round tubes just fine. It has something to do with the ellipse that Fusion isn't happy with. Hmmm.

[jhackney1972 · Accepted solution]

You can use the same method I used to create the elliptical tube and cope it to another body.  Model is attached.  You can move the timeline back and forth between the Unfold and Refold. 

[manzanitacycles]

After a bunch of trial and error, I got it to work following John's advice. But the steps involved are much more complicated than if I were just trying to do the same thing with a circular tube. Not sure why Fusion is fussier with ellipses than circles.

[Gruntc1]

So what exactly would that be? I have very nicely coped tubes, and one with a slightly straight section works always on the very ends but messing with a slot for un folding it doesn’t seem to help much