Problem in getting a flat pattern from a countour roll - Sheet Metal

[Simon_Bi]

Hello,

I've been trying to modelise the attached piece for a while and it seems that I almost got here.

This piece will be riveted to the side of a cylinder.

I cannot get the flat pattern from it.

The flat pattern would come ok only if the part remains unfolded.

And once the flat pattern is created, I cannot manage to refold the part.

Do you have any clues of what I'm doing wrong?

Thank you.

I'm using Inventor 2014

[CCarreiras · Accepted solution]

Hi!

In Sheet Metal, bend zones are very important and sensitive places to able the flat pattern.

Somehow, when you refold the part, the bend radius break in two faces (as you can see in the pic), and due this, inventor can't calculate the compensation in this bend, therefore, it can compute all flat pattern.

If you change a little the flange definitions, we can achieve the bends without the breaking issue... so, no bend issue no FP problem,  we finally have the flat pattern!!

Check the file attached.

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[JDMather]

Is there any reason you can't do all of the other features before the Unfold/Cut/Refold?

It seems to me more logical to do the flanges in the folded state anyhow?

[CCarreiras]

Hi!

The reason is, Inventor doesn't let do it.... add flanges in a curved "face".

personally, I also created this plate by another process, but he decided to go this way, so... i gave my best solution for that case.

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[Simon_Bi]

@Carlos: Thanks Carlos!
That's was a tricky one.

I just played around a bit with the definitions, changing randomly the features and it worked.
I did not fully understand why, but as you said, bends are sensitive...

You mentionned another process to create such a piece, can you give more details?

@JD: It seems more logical to me too, but when using the flange tool, the edges of a rolled part won't be selectable at all. Even after unfolding.

I had to change the unroll method of the Contour Flange from kFactor to Centroid Cylinder to be able to add flanges.

But with a single segment profile, I could not change it, that's why I use a L-shape on the first sketch.

=> do you have any suggestions to add more easily flanges, hem or bend on a rolled face?

Thank you both

Simon