Convert to Sheet Metal Flat Patterm Failure

[fergusm7JV8G]

Hello I have a bunch of files (.igs) from a factory that I need to convert to sheet metal to get the flat patterns for.

However after importing into inventor and converting, the flat pattern fails (does not flatten). I assume it has somehting to do with the bend lines not being radii. Is there any work arounds or solutions to this?

Thanks in advance 🙂

[YannickEnrico]

Inventor has trouble unfolding stuff that isn't a uniform thickness. Sometimes it has success unfolding corners that don't have the appropriate radii, but to make sure, you can introduce fillets in all bends - At least the outside one = Thickness. That'll introduce uniform thickness.

Otherwise I usually run with inside = Thickness and outside = Thickess*2

[s_ciocca]

Ciao, hai la possibilità di condividere un file?

Che tipo di Inventor utilizzi?

Se hai una versione superiore alla 2023 però non riesco a visualizzarlo...

Grazie

Stefano

[SBix26]

If you could post an example and let us know what version of Inventor you're using, someone here can show you how to do it.  In general, I think I would do the following (referring to the image you posted):

1. Set the active sheet metal style to the correct thickness (plus other style parameters that matter)
2. Use Delete Face to remove one face and all the edge faces, leaving you with a set of surfaces defining one side of your part
3. Use the Fillet tool to add the proper inside (BendRadius) and outside (BendRadius + Thickness) radii
4. Use the Thicken tool to turn that set of surfaces back into a solid body (Thickness)

Now it should flatten as expected.

Some of this is pretty tedious, depending on the contours of the part, but window selection can be very helpful.

Hope you can figure it out, but if not, please post back.

---

Sam B

Inventor Pro 2025.2.1 | Windows 11 Home 24H2

[pcrawley · Accepted solution]

I agree with all the previous posts!  It can be a bit tedious, and non-uniform thickness can be a real headache - but the tips above will get you round that issue.  If you are lucky though, many of the steps should be a little less painful:

When you click "Convert to Sheet Metal" Inventor asks you to "Select base face" - and this automatically measures (and sets) the SM material thickness:

After that, whatever your SM Style is set to takes over, and you can simply add a "Bend" feature to the sharp edges:

[fergusm7JV8G]

Thank you Peter this worked!! I tried applying fillets with no success but clicking through and allocating the bends worked wonders and is definitely the quickest option. 

Cheers everyone for the help.

[pcrawley]

Glad it worked for this instance.

The workflow from @SBix26 would be my normal "go to" because it resolves the non-uniform thickness problem.  As mentioned in point 2 - you need to delete all faces except the finished surface - and then point 3 - add the fillets.  The fillets will be either inside or outside radii - and getting those correct is the key to the final thickening step to work.