topic Re: Sheet Metal takes forever to fold back a sheet... in Fusion Support Forum

Sheet Metal takes forever to fold back a sheet...

petrara — Tue, 05 Mar 2019 21:22:53 GMT

I used a modified rule for a sheet metal (thickness 12mm, K-factor=1), to make a plywood element. I extruded the sheet from a profile sketch.
Second, I unfolded the sheet and edited the surface by adding several cuts, to simulate kerf bending (they were quite a lot: 56 cuts in total)... The issue is that Fusion is calculating for over half an hour already and didn't manage to bend it back.

Mentions:

- I used Rectangular Pattern to multiply the kerf cuts. If I disable the pattern, it will bend.

- I drew all kerf cuts on one of the bends on a sketch and performed the cut, this bent almost instantaneously... but the sketch became very heavy.

Observations:

- CPU was only 13% load (quad core w/ hyperthreading, so this is indication of single core use). Not sure if the sheet metal process can be optimized to use multicore... Autodesk dev team should answer
- Texture UV-mapping was NOT preserved on the unfolded sheet. As a suggestion, Autodesk might want to implement a feature of planar mapping on the unfolded sheet, which would then preserve the layout when folded back. Would be a neat way to apply visual information sheet-metal parts.
- (Rectangular) Pattern seems to have a problem being computed by Sheet Metal Folding feature

!Edit: - Instead of selecting "feature" for pattern, I selected the faces of the cut operation and the sheet was bent. Unfortunately, there was slight misalignment in how cuts were distributed...

- Why Fusion 360 doesn't actually have a Kerf Bending feature anyway?? If you'll look at the attached image, you can see the kerf cuts have their shape preserved, and the material BETWEEN cuts has been compressed. While this won't prevent me from making the model, is not the way a kerf bending works... and I am sure F360 CAN compute that (read as: Autodesk devs are smart enough to implement it).

Reasons why I did this (as seems quite unnecessary step of work):

- university project (F360 is in our programme, so we use it for uni projects)

- visualization (to present the project)

- to be able to assess the amount of material needed

Question(s):

- Any suggestion on how I could improve the calculation, so I can actually have a bent profile, without crashing Fusion?
- Any suggestion whether I should have done it differently for a better result?

- Will Autodesk consider the suggestion of implementing some woodworking features (like kerf bending in sheet metal workspace)?

Re: Sheet Metal takes forever to fold back a sheet...

karina.harper — Tue, 05 Mar 2019 22:19:51 GMT

Hi @petrara

I'm going to do my best to answer your questions - there's a lot here so I'm going to try and go through one by one. Also - if you could add your file here, I will be able to answer some of these better.

Observations:
- CPU was only 13% load (quad core w/ hyperthreading, so this is indication of single core use). Not sure if the sheet metal process can be optimized to use multicore... Autodesk dev team should answer

- Texture UV-mapping was NOT preserved on the unfolded sheet. As a suggestion, Autodesk might want to implement a feature of planar mapping on the unfolded sheet, which would then preserve the layout when folded back. Would be a neat way to apply visual information sheet-metal parts.

Fusion almost always uses single core. Multicore is utilized in CAM, but for now most operations are single core only. You might add this suggestion as well as the Texture UV mapping to the Idea Station as I don't see them there yet.

- (Rectangular) Pattern seems to have a problem being computed by Sheet Metal Folding feature
!Edit: - Instead of selecting "feature" for pattern, I selected the faces of the cut operation and the sheet was bent. Unfortunately, there was slight misalignment in how cuts were distributed...

I'll need to see the file in order to completely understand what you're talking about or give a recommendation for how to better accomplish this.

- Why Fusion 360 doesn't actually have a Kerf Bending feature anyway?? If you'll look at the attached image, you can see the kerf cuts have their shape preserved, and the material BETWEEN cuts has been compressed. While this won't prevent me from making the model, is not the way a kerf bending works... and I am sure F360 CAN compute that (read as: Autodesk devs are smart enough to implement it).

Well, because Fusion is a growing program. Personally, I also would love to see kerf bending implemented in Fusion, but the reality is that you are using a sheet metal functionality to try and mimic the physical properties of a totally different manufacturing method.

Question(s):

- Any suggestion on how I could improve the calculation, so I can actually have a bent profile, without crashing Fusion?

I don't see any crashes from your account except for one in the sculpt environment. We can only diagnose why you're crashing if you send in your crash reports (with notes is best). Something that was pointed out in this thread is that you may simply want to add your cuts after it's unfolded.

- Any suggestion whether I should have done it differently for a better result?

Well, assuming you are designing this for CNC, my recommendation for working with kerf/dukta would be as follows:

1. Create your design by building individual components for each piece and design it fully assembled.

2. Duplicate your file and create a version that is flattened/laid out as you would cut it.

3. In this manufacturing file, add your dukta/kerf/cut pattern that would apply best for your purposes. Sizing and pattern has been widely discussed, but in my opinion you have to test it on your stock as it totally depends on thickness/temperature/materials.

- Will Autodesk consider the suggestion of implementing some woodworking features (like kerf bending in sheet metal workspace)?

The Idea Station is again going to be the place to go here. Like I said, this would be super cool! Fusion is growing in many ways and we love feedback from our users. I will give a note though - it will likely be best received if you request a feature with kindness and a tone of mutual growth. I understand that working with software can be frustrating, but we are all in this together and your ideas and thoughts are valued.

I hope that helps answer some of your questions, and please let me know if I can elaborate on any of these points.

Karina

Re: Sheet Metal takes forever to fold back a sheet...

TrippyLighting — Tue, 05 Mar 2019 23:16:13 GMT

@karina.harper wrote:

Observations:
- CPU was only 13% load (quad core w/ hyperthreading, so this is indication of single core use). Not sure if the sheet metal process can be optimized to use multicore... Autodesk dev team should answer

- Texture UV-mapping was NOT preserved on the unfolded sheet. As a suggestion, Autodesk might want to implement a feature of planar mapping on the unfolded sheet, which would then preserve the layout when folded back. Would be a neat way to apply visual information sheet-metal parts.

Fusion almost always uses single core. Multicore is utilized in CAM, but for now most operations are single core only. You might add this suggestion as well as the Texture UV mapping to the Idea Station as I don't see them there yet.

Most CAD software I've ever worked with does that. The reason is that the math involved in creating NURBS geometry is simply hard to parallelize.

Re: Sheet Metal takes forever to fold back a sheet...

petrara — Wed, 06 Mar 2019 11:46:41 GMT

@karina.harper if you could give me an email address, I'd be happy to send you the link for the model along with some explanations of what is not working...

Thank you.

Re: Sheet Metal takes forever to fold back a sheet...

karina.harper — Wed, 06 Mar 2019 16:48:06 GMT

Hi @petrara

Thanks for the reply! You're more than welcome to private message me the file, but I will reply on the forum with answers in case others have the same question. If you prefer, I can leave out images of what you're working on.

Does that work?

Karina

Re: Sheet Metal takes forever to fold back a sheet...

karina.harper — Wed, 06 Mar 2019 21:21:45 GMT

Hey @petrara

Thanks for sending over your files.

What we're seeing:

When a sheet metal part is unfolded and kerf cuts are added and re-folded, the file either produces a very incorrect or glitchy result or Fusion hangs indefinitely.

I've logged this with our development team so they can have a look as FUS-47806 (internal reference #).

As for a workaround, what I would recommend is creating a projection off the face of the silhouette and then extruding. From there you can add the kerf cuts in the corners. That would work for visualization and rendering purposes. Then for the actual CNC portion it wouldn't be too hard to recreate what you have as a flat pattern and be able to test the bend radii of the kerf from there.

I hope that helps!

Karina