Sheet Metal - Rolled Cylinder with Folded Tabs at End Faces

[Anonymous]

Hi,

I am trying to use the sheet metal functionality to generate a flat pattern of insulation that is wrapped around a tank.  The insulation essentially consists of a rolled cylinder with tabs at the cylinder ends that are to be folded inward to cover the end plates.  I can't seem to find a way to make this happen as every time I am able to generate the tabs in the folded model they don't unfold into the flat pattern.

Any suggestions?

I am using Inventor 2010.

Thanks in advance.

[mrattray]

I think your problem is the fold feature being between the unfold and refold. How do you refold a fold?

Try modeling the "fingers" in the folded state.

[JDMather]

Contoured Flange

Cut Across Bend

Your "rip gap" in Sketch1 is not symmetrical and uninspectable/unmanufacturable angles.

 Unfold2, Mirror3 and Refold2 are not needed to Cut3 that feature.

[Anonymous]

@mrattray - I eliminated the unfold and refold and tried suggestions from JDMather.  See below.

@JDMather - I fixed the rip gap symmetry issue, and agree Unfold2 is unnecessary for Cut3.  In reality this thing is a cloth that will be wrapped around a tank and I am simply trying to get the blanket template made to avoid unnecessary rework at the installation phase.

I tried creating a Contour Flange; however, I cannot select the round "edges" of the cylinder.  I was able to insert a Contour Roll and also a simple revolution, but neither of those flatten out either.  A new version of the part is attached to illustrate what I have done. 

Any more suggestions or examples?

Thanks for your help.

[JDMather]

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@Anonymous wrote:

.. 

I tried creating a Contour Flange; however, I cannot select the round "edges" of the cylinder.  I was able to insert a Contour Roll ...

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Oops, that is what I meant - Contour Roll.

[JDMather]

Looks like this one is going to be a bit of trouble - I'm not sure there is a solution that will unfold (it should, but doesn't).

It will be a couple of days till I can take a close look.  Push the thread back to the top if someone doesn't post a solution.

[Curtis_Waguespack]

Hi joshiroc,

Please see attached (2010 file) for some ideas on how to proceed. I'm a bit short on time, but post back if you have any questions and I'm sure some one will be able to help.

I hope this helps.
Best of luck to you in all of your Inventor pursuits,
Curtis
http://inventortrenches.blogspot.com

[JDMather]

Curtis - now add the "crimp zone" on the side of the cylinder.

I could get flat pattern with one or the other - but not both - in my quick experiment.

[Curtis_Waguespack]

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@Anonymous wrote:

Curtis - now add the "crimp zone" on the side of the cylinder.

I could get flat pattern with one or the other - but not both - in my quick experiment.

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I just noticed that the flat pattern is not going to give the angled slits that are most likely needed to manufacture this, so I think my attempt won't work anyway.

Edit: looking back the original file it looks like his slits weren't near as tight as I was attempting to make them, so I suppose it would work. I'll try the "crimp zone" a little later if I get a chance just to check, but I'm sure there's not anything that I'd come up with that you didn't try.

[mrattray]

That's the same obstacle I just hit with my attempt. The flat doesn't actually correspond to the what's needed.

Note: I know my attempt here is pretty sloppy, but I didn't want to spend too much time on it until it worked, which it doesn't.

[JDMather]

I didn't really have time to look at this. 

[Anonymous]

The examples file was helpful.  I was able to get the folded tabs in the flat pattern.  In reality I don't want to cut wedges out of the blanket, but rather have the blanket overlap on the ends when the tabs are folded radially inward.  The flat pattern that is generated with the suggested approach works for my application.

That said, I now can't seem to get the axial channel that was in the original model added in to the contour rolled geometry.  Any suggestions or examples for getting it incorporated to the model?

Thanks.....

[JDMather]

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@Anonymous wrote:

That said, I now can't seem to get the axial channel that was in the original model added in to the contour rolled geometry. 

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Can you attach your current itteration here so that someone doesn't have to recreate those features.

[Anonymous]

Here is a file in rough form.  I cut back on the number of tabs simply to speed up modeling computation time.  I am purely focused on a method that will work and not so much on the correct geometry.

Sketch6 illustrates the general shape of the channel feature that needs to run axially along a part of the cylinder length, althgough I was unable to actually generate the desired flange.  The first file I uploaded in the original post contains the axial channel and correctly unfolds, although the end tabs don't.