Flat pattern problems with contour roll

[frugal]

I've been working for quite a few days now on one single corner detail in the sheet metal suite.

Mcgyvr just solved a forehead slap problem that had me stumped this morning but now I've run into another one...

At least I can now draw the detail I want:

This is a rolled flange, two contour flanges, a cut and then a rip. 

The problem with this one is that the flat pattern is incorrect. The "ears" of the mitered corner are wrong.

I also got close to a solution using a different approach:

This was more complicated and is not quite right because I can't get rid of the gaps between the contoured parts and the original flanges.

It would be good enough to give to the fabricator with a note, but it wont unfold.

Both IPTs attached.

Many thanks in advance. I don't know what I would do without the folks on this forum.

Thomas

[TheCADWhisperer]

---

@frugal wrote:

It would be good enough to give to the fabricator with a note, but it wont unfold. 

---

I think you better discuss with the fabricator how that corner will be manufactured.

[frugal]

Indeed yes, I would like to discuss it with them.

I know it is possible because I have seen an example - but I need a plausible set of drawings in order to begin the conversation!

[IgorMir]

Hi Thomas,

I would have addressed that design a bit differently. Here is what I can offer. Please see the attached file in IV2010 format.

It took 10 minutes to model, BTW. 🙂

Cheers,

Igor.

---

@frugal wrote:

I've been working for quite a few days now on one single corner detail in the sheet metal suite.

Mcgyvr just solved a forehead slap problem that had me stumped this morning but now I've run into another one...

At least I can now draw the detail I want:

This is a rolled flange, two contour flanges, a cut and then a rip. 

The problem with this one is that the flat pattern is incorrect. The "ears" of the mitered corner are wrong.

I also got close to a solution using a different approach:

This was more complicated and is not quite right because I can't get rid of the gaps between the contoured parts and the original flanges.

It would be good enough to give to the fabricator with a note, but it wont unfold.

Both IPTs attached.

Many thanks in advance. I don't know what I would do without the folks on this forum.

Thomas

[IgorMir]

Here are some small changes to a previously sent part.

Cheers,

Igor.

---

@IgorMir wrote:

Hi Thomas,

I would have addressed that design a bit differently. Here is what I can offer. Please see the attached file in IV2010 format.

It took 10 minutes to model, BTW. 🙂

Cheers,

Igor.

[frugal]

Hi Igor,

Thanks for taking the time to model that. However, the challenge here is that I really need to keep the rolled contour on the corner.

Your method exposes both edges and corners which I cannot do...

Many thanks again.

[IgorMir]

Hi Thomas,

Then you have to forget about getting a flat pattern from within the Inventor. That part would be for rolling, not for the break press.

As it was suggested earlier - talk to the manufacture and seek his advise.

Cheers,

Igor.

---

@frugal wrote:

Hi Igor,

Thanks for taking the time to model that. However, the challenge here is that I really need to keep the rolled contour on the corner.

Your method exposes both edges and corners which I cannot do...

Many thanks again.

[IgorMir]

On a second thought - here are two more models which deliver a flat pattern. Which one is to your liking, Thomas?

Cheers,

Igor.

---

@IgorMir wrote:

Hi Thomas,

Then you have to forget about getting a flat pattern from within the Inventor. That part would be for rolling, not for the break press.

As it was suggested earlier - talk to the manufacture and seek his advise.

Cheers,

Igor.

---

@frugal wrote:

Hi Igor,

Thanks for taking the time to model that. However, the challenge here is that I really need to keep the rolled contour on the corner.

Your method exposes both edges and corners which I cannot do...

Many thanks again.

---

[IgorMir]

After comparing flat patterns between Part2 and Parts3 & 4 - there is a certain inconsistency in it. I would have expected the flanges mitred edges been of the similar appearance in a Flat Pattern as they are in Part2. But they are not. Unfortunately -  beyond that observation I can not add anything else...

[frugal]

Hi Igor,

Interesting. Both of the flat patterns in Inv 2017 are similar.

Your Part 4 and Part 3 as flat patterns:

   

The first flat pattern is incorrect. I've marked one error in red. After I posted the photo I realised that there is a second error as the top edge of the rectangular cut out should be an arc. It looks like the algorithm is assuming that the flanges also be rolled.

I think that the flat pattern in the second may technically be correct (though it may or may not actually work) if the entire part were to be rolled.

My conclusion is that the correct flat pattern will have to be made by amalgamating two patterns together - one with a mitered corner and no rolled contour and another just to calculate the material required for just the contour on the corner itself.

The miter ears for the corner would look something like the flat pattern from Igor's Part2:

Many thanks - at least now I know how to work around the problem in order to make a drawing to discuss with the fabricator...

Best,

Thomas

[IgorMir]

Hi Thomas,

That's my conclusion as well... 

Cheers,

Igor.

---

@frugal wrote:

My conclusion is that the correct flat pattern will have to be made by amalgamating two patterns together - one with a mitered corner and no rolled contour and another just to calculate the material required for just the contour on the corner itself.

Many thanks - at least now I know how to work around the problem in order to make a drawing to discuss with the fabricator...

Best,

Thomas

---