Sheet Metal part won't unfold

[d.m.polsky]

I'm having the hardest time mastering sheet metal. On the project I'm currently working on I drew the outline of the parts, and then drew in the bend lines and just used the fold command. That seemed to work pretty well for the most part. I'm now on another part, and I kept getting errors when I was doing it that way, so this time I tried starting with a face and just adding flanges all over it. It seemed to create the part okay, however it won't unfold.

Maybe I'm doing this all wrong anyways.

Thanks,
Daniel

End.zip

[JD Mather]

Your part is modeled incorrectly.

I would (almost) never use the Fold command.
Model the part in finished form (which makes your Sketch1 wayyyyyyyyyy too much work).

Drag the End of Folded Marker to just below Hole1 in the browser.
Click Flat Pattern. This feature does not look correct to me. I would expect a Cut Across Bend.

Go back to the Folded Model.
Drag the End of Folded to just below the Flange5 feature.
Notice that it interferes with Flang3 and you get an error message.

I would start over with Flange4 as my very first feature (and it would be Face1 feature).
When modeling a sheet metal part you should not care one iota about the flat pattern during the modeling stage.
The customer pays for the finished form. The finished form performs the function. You know the dimensions of the finished form as it fits into your assembly. Avoid any calculations.
Model as finished and let Inventor figure out the flat pattern for you.

[d.m.polsky]

Thanks for the advice, that must be my problem, making the transition from AutoCAD to Inventor, all of our drawings in AutoCAD were flat patterns. We never developed 3d models, we designed our parts knowing what happens to the flat pattern when folded up.

Thanks,
Daniel

[JD Mather]

... all of our drawings in AutoCAD were flat patterns. Thanks,
Daniel

The problem with this method is that it takes all kinds of calculations to get the desired finished part. When we make calculations we tend to make mistakes (not to even cost the time of making these calculations).

But we usually know what the finished dimensions are - so it is relatively easy to model in finished form and then let the software calculate the flat pattern.

And also, when we bend a sheet metal panel the metal compresses on the inside of the bend and stretches on the outside of the bend. We might not have to worry too much about this stretching as most sheet metal isn't particularly close tolerance, but if the tolerances are close - Inventor calculates this Bend Allowance for us when creating the flat pattern.