Sheetmetal flat pattern error

[Anonymous]

When folding sheet metal with overlaps that mate, it can be difficult to keep faces from merging. I can get around this by unfolding certain faces before creating others. Additionally, the "Create Flat Pattern" fails unless I manually unbend some bends. This happens because there are collisions if you do not unfold the part / fold the part in the correct order (I am 100% sure these parts are possible to make because I have made them, but inventor doesn't think so).

This makes it very confusing to make BoMs, drawings, and track revisions because I have to make two parts, one that unfolds and one that does not for any parent assemblies. Is there a better workaround?

Attached is an example part. Notice that if you "End" the part above the "Refold" the flat pattern works. I hope it makes this issue clear. This may seem like a very odd problem, but it comes up in many of my sheetmetal parts. 

Thank you,

Mateo

[Paul.Normand]

Hi,

In opened the example you sent, deleted the Unfold/Refold operations and saw the merge faces problem you described. 

I took a different approach to the problem and created an offset workplane with a very small gap to keep a separation. I then created a Face and connected it to the body with a Bend feature. It unfolds nicely.

I forgot to check which version of Inventor you have. Inventor 2016 Model is attached. This technique works fine with older versions too, so let me know if you need a Screencast video of the workflow.

-Paul

[Anonymous]

I have also used this method (create a very small gap). It works, but is not ideal. I got questions from suppliers like: "There is a gap in the file, is it ok if there is no gap?" In reality, there is no gap. I usually get these faces spot welded.

If there are no other responses here, I'll mark yours as the solution but ideally it is not.

[Paul.Normand · Accepted solution]

Will the ability to create a flange with a small tolerance value so that it does not merge with the body be an acceptable solution? This would bypass the need to create an offset workplane, face, and bend, If so, I will talk to development to see if we can get something like this added to the flange command,

Also, can you mark this as a solution since no other responses have been addded?

Thanks,

Paul

[Anonymous]

This sounds like a good way to bypass the problem. I have marked it as the solution, but it would be better if there was a 0 tolerance option (faces mate, but don't merge)

[arkelec]

Has this feature now been added?  Is it available for the version in Building Design Suite Ultimate 2015?

[JDMather]

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@Anonymous.elec wrote:

Has this feature now been added?  Is it available for the version in Building Design Suite Ultimate 2015?

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Can you attach your file here?

[arkelec]

To update, I received this reply from Autodesk:

I found that if I change the Inner flange radius to 90.01 this will create a flat pattern:



I will be sending this to our development staff for them to review.
Please do not have you customer try this in Inventor 2017.
Inventor 2017 exits to a CER while trying to create a flat pattern form this file.

This proved to be a suitable workaround for me.  I've downloaded 2017 Suite, but not installed yet.  

Panic over.

[Anonymous]

What is a CER? and will 2017 have a fix for this soon? I am about to download 2017 (currently have 2016)