topic Re: sheet metal: Converting flat pattern to complex curved shape in Inventor Forum

sheet metal: Converting flat pattern to complex curved shape

SPK009 — Mon, 17 Mar 2025 13:46:18 GMT

So, I have been struggling with this for weeks now.

I have 2D patterns cut and pasted from AutoCAD into Inventor to create a CAD model of a skin sheet for a rounded structure (think of an Airstream or an aircraft body - included in the screenshot). I have included the dwf of the panel and the profile it needs to bend to. To make matters worse, I need to be able to adjust the location of the pattern with respect to the curves (as finer details from the original project were lost - how the patterns were made in the first place and now I have to recreate them).

As you can see from the image provided, I have managed to do the panels on the top and bottom, because they were easy curves with only one radius... not the case with the sides. I have followed every tutorial and guide (successfully making the tops and bottoms), importing the shape, doing a contour flange, and then unfolding and its always an error - I've also just experimented with extruding them first, THEN converting to sheet metal - still only errors. I'm lost.

Any help would be appreciated.

Re: sheet metal: Converting flat pattern to complex curved shape

johnsonshiue — Mon, 17 Mar 2025 23:57:38 GMT

Hi! Inventor Sheet Metal workflows were designed to build the folded model first. Then the Flat Pattern will be created as a result.

Though there are workflows allowing you to bend a flattened Sheet Metal part, it kind of defeats the purpose of building the folded model.

Please share what you have right now. The forum experts can help take a look and suggest a good workflow.

Many thanks!

Re: sheet metal: Converting flat pattern to complex curved shape

SPK009 — Tue, 18 Mar 2025 09:44:27 GMT

I have included my "not working" version, which I have managed to create the "unfold" and put the cut pattern on, but now wont refold.

Thanks so much.

Re: sheet metal: Converting flat pattern to complex curved shape

johnsonshiue — Tue, 18 Mar 2025 19:27:04 GMT

Hi! Many thanks for sharing the part! I believe this has something to do with lacking of planar unfold reference. The Refold already has trouble going back to the proper orientation. To fix the issue, simply add two tangent lines at both ends in the sketch consumed by the Contour Flange. After that, the Unfold/Refold will work correctly. Please take a look at the attached part.

Thanks again!