sheet metal flat pattern problem

[rasprojects]

Hello,
I have a problem resolving a sheet metal flat pattern situation.

Capture-2 shows the complete corner with on 2 sides a flange with radius from 20mm, and also the corner with a radius from 20mm.
The problem is within the corner with R=20

I modeled it as a solid box and made fillets on the 2 sides and the corner, then i used Shell and got the correct end product. Convert it into a sheet metal part, but its not possible to make a flat pattern from this.
To produce this you need 3 cuts in that corner, so you can make a flat pattern. (Capture-4: see my sketch how it must look like if it would be a flat pattern)
But I’m not able to make these cuts.

This is a problem that i have for more then 2 years and never found a solution.
Is anyone knowing how to solve this?

Best regards,
Richard

[CCarreiras]

Hi!

The cad file would help to find some answers.

[philip1009]

It's recommended to only use the sheet metal environment and tools to create the model to eliminate as many errors as possible, starting with a shell of an extrusion isn't the best starting point.  An example cad file or drawing would help with determining what can be done and to possibly provide you a good example.

[SBix26]

Adding on to @philip1009 's post, use the sheet metal tools.  Corner settings are highly configurable.  See picture below for an example, with 5 mm material, 20mm outside corner radius.

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Sam B
Inventor Pro 2020.1 | Windows 7 SP1
LinkedIn

[rasprojects]

Im sorry i forgot to include it.

I include it in this reply.

Best regards,

Richard

[rasprojects]

Thanks for your reply.

I know that its the best thing to do, to work only from the sheet metal environment, but i was not able to make the corner also with an R20mm.

That is how i ended up finding the solution to shell a solid, but its not really a solution for the production. It only shows the model correct but no flat pattern.

The IPT I included in my previous post, so hopefully it can help.

Best regards,

Richard

[rasprojects]

Thanks for your reply.

As your model shows 2 sides with an R20.

My model needs also the corner with an R20.

The problem is in that corner. (see jpg attached)

I  cant find out how to do this in the sheet metal environment.

I included the IPT in a previous reply so please see if you see an solution.

Best regards,

Richard

[SBix26]

How is this box going to be fabricated?  If it will be made from sheet metal, then the corner will be finished by welding and grinding, or caulking or some other process.  Inventor does not have the ability to show a sheet metal part with a proper flat pattern and a finished weld.

This could be done, however, in the weldment assembly environment, by placing the formed model in the assembly, then applying welds and machining processes.

You could also have both versions by using Derive from the finished model to another part file, then filling in the corners in that file (or, do both versions in the original file using pattern new solid, then derive both versions into separate files for flattening, etc.).

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Sam B
Inventor Pro 2020.1 | Windows 7 SP1
LinkedIn

[JDMather]

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@rasprojects wrote:

This is a problem that i have for more then 2 years and never found a solution.
Is anyone knowing how to solve this?

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Do you make these parts "in-house", or are they made by an external vendor?

Can you post an image of real world part showing that corner?

Are you aware that as you have designed the corner will require a deep-draw punch?

If you are aware of all of the above... 

you might be able to use the new Unwrap functionality.

[philip1009]

Here's an example of how that corner is formed and the resulting corner notch.

[johnsonshiue]

Hi! If I understood the request correctly, I don't believe there is a good solution to make a sheet metal part and create such flat pattern within one ipt file. You will need two files. One is the folded part and then you can derive it and to tweak it with deformation at corners so that the flat pattern can be made.

Many thanks!

[rasprojects]

Thank you for your reply.

The parts are produced at and external vendor.

After receiving, the corners will be formed manually by our craftsmen.

I include a picture off the part that we receive.

As you see its not produced with a punch tool. They made cuts in the sheet metal and bend the long sides. the left over material will be modeled by us manually. 

Thanks for the unwrap tip. I forget about this new option. Its a good option when it would be punched, but as you see on the picture its really made off a flat patter with cut-outs in the corner (see capture -4.jpg).

Its clear how they produce it, but i do not know how to included these cut-outs in the model and have a visible end product with all the bends and a flat pattern.

Best regards,

Richard

[rasprojects]

Thank you, but its without the corner.

This bending on the long sides is no problem, the problem is in the corner.

[rasprojects]

Thank you for your reply.

I see also a similar reply from SBix26 and think that there is no easy solution.

As you wrote: "You will need two files. One is the folded part and then you can derive it and to tweak it with deformation at corners so that the flat pattern can be made."

This sound complicate to me and I am not at that level that i know how to perform this.

Is there a tutor online were i can see that method, or are you able to send a sample?

Best regards,

Richard

[JDMather]

It would have been very helpful for you to include these two images in your original problem description.

I think this is a solvable issue, but it could be several weeks till I would have time to investigate

Hopefully now with these images - someone will take up the challenge....

….oops, I guess you realize this will require two different files.

[rasprojects]

Thank you JDMather,

There are many people on the forum with much experience, so  I hope somebody will take up the challenge, but if not, several weeks sound also not bad,  I am searching a long time for a solution so a few weeks more is no problem 🙂

 I understand that it requires 2 files but that would be no problem.

Is there a way for me to include the extra images into the first message I posted?

I looked if i can edit the original message but i was not able to find it.

Best regards,

Richard

[JDMather]

I will embed them here - not likely to be missed.

I think the solution will be pretty easy.

[SBix26]

I see now how the flat pattern is used to create the finished corners.  Inventor could almost do the job for you, but not quite.  The spherical corner section requires deformation of the material to fold the two small sections together.  Inventor cannot provide a flat pattern of this feature, even if it is ripped properly.

I tried adding small rips in the corners, and was surprised that Inventor actually produced a flat pattern, though with errors and with the spherical sections only partially flattened (attached file is Inventor 2020 format):

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Sam B
Inventor Pro 2020.1 | Windows 7 SP1
LinkedIn

[rasprojects]

Thank you SBix26,

This is the solution i think.

I do need to figure out how you did the revolution 1, but it works great.

I took your model and then unwrap it, made a sketch from it and made from the sketch a new solid.

Tomorrow i will continue to see if the flat pattern is in the correct dimensions.

But it seems that its solved.

I included the flat pattern in this message.

Tomorrow i will report back to you all.

Best regards,

Richard

[rasprojects]

Hi all,

Today i checked the (flat pattern) and it has some issues.

The horizontal and vertical lines were bended (like an arc). They were not straight any more. I think its because I used the unwrap function. The difference I measured between 0.2 and 0.4mm. I know its not so much for this item, but it would be good if its a 100% flat pattern.

The solution is so close so i leave the question unresolved.

For this moment i like to thank all for your thoughts and help.

Hopefully someone will come up with a 100% solution.

Best regards,

Richard