topic Re: Issue with shell function in Fusion Support Forum

Issue with shell function

uminskitj — Wed, 22 Oct 2025 16:58:12 GMT

Hello, I am trying to make a pipe that is oval on one end and round on the other with a 45 degree bend in it. The round end needs to be 4.25" ID, and the oval needs to be 5.5"x4.125" ID. The pipe should have a wall thickness of .23". I have built my ends, and drew the path and connected it with the loft function. Then I shell out the inside, but I can never get it to achieve the correct dimensions. I have even tried adjusting the sketches to be bigger and shelling on the inside, but that still doesn't give me the correct dimensions. Is there a better way to make a pipe like this? What am I doing wrong?

Re: Issue with shell function

TheCADWhisperer — Wed, 22 Oct 2025 17:20:10 GMT

@uminskitj

Your work plane is not at the end of the line (Proportional =1) I doubt that is what you intended.

Re: Issue with shell function

uminskitj — Wed, 22 Oct 2025 17:27:55 GMT

Thank you for pointing that out. I have corrected it, but it doesn't help the issue I am having. Or maybe it does, but I don't know enough for it to be apparent to me.

Re: Issue with shell function

TheCADWhisperer — Wed, 22 Oct 2025 17:29:41 GMT

@uminskitj wrote:
The round end needs to be 4.25" ID,

This doesn't make logical sense.

Your circle is 4.25 and you Shelled towards the inside.

Are you sure you didn't mean to write OD rather than ID, or did you Shell towards the wrong direction?

Re: Issue with shell function

TheCADWhisperer — Wed, 22 Oct 2025 17:33:44 GMT

@uminskitj wrote:
and the oval needs to be 5.5"x4.125" ID.

Did you intend to Shell towards the outside?

That would return the ID dimensions that you specified in your problem description.

Re: Issue with shell function

TheCADWhisperer — Wed, 22 Oct 2025 17:37:14 GMT

@uminskitj

See my step-by-step analysis.

I have to wonder if you want any portion of the ends to be extruded rather than continuous Loft along length.

For example, a portion of the round end to be cylindrical for connection to a pipe.

Re: Issue with shell function

uminskitj — Wed, 22 Oct 2025 17:44:42 GMT

Yes, I intended to shell towards the outside because I started with my desired ID's. Whether I shell inside or outside, I get the same inner dimension. Every time I try to go to the outside, I get an equal out of thickness formed on the inside too. I have attached a screenshot. My command is to shell to the outside by .23". The white line is my original sketch (4.25") and the highlighted blue are is the amount it grows it on the ID.

Re: Issue with shell function

TheCADWhisperer — Wed, 22 Oct 2025 17:51:31 GMT

@uminskitj

You did not Attach the new file?

Change the Shell type to Sharp

I also noticed that this circle was is not constrained to the center line.

Blue curves should keep you awake at night.

Re: Issue with shell function

uminskitj — Wed, 22 Oct 2025 17:59:46 GMT

That worked, thank you for the help!