Refold Stationary Surface problem

[0x3FA5]

Hi,

I ran into a bizarre refolding issue.

On a simple SM part, when selecting "Unfold", it flattens the part as expected:

But after a few manipulations, in particular adding a Fillet, when trying to "Refold" the part is randomly rotated:

Even though the "Refold" Feature was selected directly from the parent "Unfold" menu:

I tried to create a few "Refold" features, refolding each set of bends individually, did not help.

Would highly appreciate your help.

Thank you.

[joseph.hoermann]

@0x3FA5 Thank you so much for attaching the part. Unfortunately I was not able to recreate the same issue on my end. Do you mind making a screencast of the steps you are taking in order to produce the unexpected behavior? Thank you so much!

[SBix26]

(Note: always tell us what version of Inventor you're using in the first post...).

I opened your file in Inventor 2018 and found the same problem that you did, but only when I applied a Corner Round (Fillet) to the corners circled in red below:

---

Sam B
Inventor Pro 2020.0 | Windows 7 SP1
LinkedIn

[0x3FA5]

Thank you for your replay.

Yes, that's what I don't understand, the fillets twisting the stationary surface?

[0x3FA5]

I will have to install it first, thank you for your reply.

[JDMather]

My first thought is to not even use Unfold/Refold.

Start a New Sketch on the Face of the part.

Use the Project Flat Pattern (rather than Project Geometry) and select the flange to unfold.

Sketch in the profiles for the cut (including the fillet arcs).

Cut Across Bend.

I will post example later tonight when I get to a machine with 2018.

[Sergio.D.Suárez · Accepted solution]

Hi, look at the video, the problem as described above is generated when making a fillet on a fold edge, something not recommended, note how irregularly the fold edge after the fillet. One way you could use would be to make the fillet in the cut sketch, as you will see the crease edge will not be affected. Greetings.

[johnsonshiue]

Hi! Indeed, this is related to the bend zone. When you add the corner round in unfolded mode, the round alters the bend in the way it is no longer recognized as a bend. You can turn on edge display to see the wacky bend zone.

The workaround in this case is to create the fillet in the Extrusion sketch instead. Then Refold will work correctly.

Many thanks!

[JDMather]

@0x3FA5 

You didn't indicate the desired Fillet size.

Is something like the Attached what you are after?

[IgorMir]

Hi Johnson;

In such a case - the model would fail with even one corner round present. But no, with just one corner round it works as expected. It is when both corner rounds are applied - that's when the refold jumps into arbitrary direction.

Cheers,

Igor.

---

@johnsonshiue wrote:

Hi! Indeed, this is related to the bend zone. When you add the corner round in unfolded mode, the round alters the bend in the way it is no longer recognized as a bend. You can turn on edge display to see the wacky bend zone.

The workaround in this case is to create the fillet in the Extrusion sketch instead. Then Refold will work correctly.

Many thanks!

---

[0x3FA5]

Hi,

Thank you for the reply! I will definitely explore the project Flat Pattern.

This seems to be interesting:

>My first thought is to not even use Unfold/Refold.

Is this option going to be discarded in the future versions of Inventor?

It's just very strange that such a basic option would perform that badly and require a workaround...

[JDMather]

I meant only to not use Unfold/Refold in this particular case.

Unfold/Refold is appropriate in other cases.  I doubt it will ever be removed from the toolset.

[IgorMir]

Hi;

I personally don't see anything inappropriate with using Unfold/Refold way of modeling in your file. Here is your slightly modified model. 

Cheers,

Igor.

---

@0x3FA5 wrote:

Hi,

Thank you for the reply! I will definitely explore the project Flat Pattern.

This seems to be interesting:

>My first thought is to not even use Unfold/Refold.

Is this option going to be discarded in the future versions of Inventor?

It's just very strange that such a basic option would perform that badly and require a workaround...

---

[joseph.hoermann]

@IgorMir Do you still need help with this issue? If not do you mind marking a response that you see as a potential solution. If not do you mind clarifying further?

[johnsonshiue]

Hi Guys,

This is a bug and a limitation. The bug here is that the Refold should be able to stay put. The limitation here is the corner round command cannot properly handle the bend zone. Regardless, there is room for improvement. The reason why one side corner round works is because the bend zone is not completely changed. The reference to the original bend zone remains available. But, when both sides have the corner rounds, the bend zone is cut off confusing Refold command.

Many thanks!

[IgorMir]

Hi, Joseph;

Me? Do I needed a help with this issue? I afraid - you have got yourself confused. 🙂

Cheers,

Igor.

---

@joseph.hoermann wrote:

@IgorMir Do you still need help with this issue? If not do you mind marking a response that you see as a potential solution. If not do you mind clarifying further?

---

[IgorMir]

Thanks, Johnson!

Cheers,

Igor.

[joseph.hoermann]

@IgorMir Yes, my mistake! I apologize. Thank you anyway.