Trying to make sheet metal rules work for paper product prototyping

[mark57KWB]

Hello Fusion Experts,

I'm a new Fusion 360 user trying to prototype food packaging products such as a cereal box.  The sheet metal rules system seems to be the only one that allows for folds and bends and it's almost exactly what I need.  But the self-intersection constraints and error checking are strict and prevent making the type of folds I can make with cardstock, Kraft paper, and the like. 

I'm wondering if there is any way to disable some of these checks or otherwise allow the behavior of a material besides metal to apply.  I am not looking to avoid best practices and I've taken steps such as notching the corners and offsetting conflicting bends but it ends up looking unrealistic.

This is a simple example of something I'm trying to model in Fusion 360:

If I try to bend this line at all, it fails with errors cited above.

I have added offsets like below and tried every Bend / Relief / Corner Override I can find.

I followed a tutorial that used flanges to accomplish these types of bends and it does work but it ends up with unnecessary gaps and not very representative of the material and shape to be manufactured.

I'll attach the Fusion file I've been working with in case anyone has any ideas or tips.  

Appreciated,

Mark

This was the first 

[TheCADWhisperer]

Bumping this back to the top.

I would model in finished folded form rather than Fold from flat.

Fusion will return the Flat Pattern.

Might require some hybrid modeling techniques.

@mark57KWB 

How much interest do you have in achieving workable “solution”?  The reason I ask is because I have spent time trying to help several people lately who abandoned any effort on their part.

[mark57KWB]

Thanks for your reply.   My goal is to understand what design tools are used by paper product manufacturers.  

I expect organizations such Coca Cola, UPS and Amazon design their packaging with precision using CAD tools.  It would interesting to learn if they accomplish this with Fusion 360?  If so, are there configurations, rules, or best practices they utilize for industrial paper product manufacturing, that I can use too?  I was wondering if this type of design work is already being done and if the community had suggestions on how to configure the environment to support paper manufacturing design.  

I found one example of a designer that created an additional sheet metal rule based on the specifics of cardboard.  It's included in the attached file.  I created an additional sheet metal rule to reduce the thickness of the material from .067" (cardboard) to .38mm (cardstock).  These updates help but I'm unsure if these or even sheet metal in general is the best method.  Another suggestion I learned was to use the surface workflow with the ruled surface feature, which is not constrained by the bend limitations.

In summary, I'm hoping to hear any community opinions, suggestions or experience withFusion 360 used for paper manufacturing.

Appreciated,

Mark

[mark57KWB · Accepted solution]

In case anyone encounters a similar problem, this is how I (with help from an experienced colleague) resolved the problem(s). 

My workflow had been:

1. Create sheet metal component
2. Create sketch to design the flat base of the part
3. Extrude that body to cardstock thickness
4. Convert to sheet metal (unsure why this was needed) 
5. Create sketch with bend lines defined
6. Create bends, generate errors

Functioning workflow:

1. Create a sheet metal component
2. Create sketch to design the entire part, including bend lines
3. Use the flange feature to thicken/extrude the face to cardstock thickness (.38mm)
4. Use the bend feature to bend the hinges up off the surface plane.
5. Create sketches on the new bent short edges
6. Use the bend feature to bend inward the 2 short edge triangles.
7. No errors. Unsure why this works and the previous fails.

 

A few other items that may help others:

1. The physical material I used to represent cardboard and kraft cardstock is bamboo. There are some wood materials that are close also.
2. I still needed to create a small offset at the corner as described in the original post, figure 2.
3. You'll probably want to create and save the width of the paper product as a new sheet metal rule to your library so you'll  have it available for other projects:

I think this gets me most of what I need to design for paper manufacturing.  I'd still be interested to learn what the professionals use in the food packaging and shipping industries to design boxes, in case anyone knows.   I should have posted this in the Fusion 360 Design, Validate & Document forum or perhaps the Fusion 360 Manufacture forum since this is more of a usage question than a bug report.

[miantonio]

One option you might consider is using the Direct Edit tools in Fusion 360 to manually shape your packaging design. This will allow you to create folds and bends without the strict self-intersection constraints. You can also use the Push Pull tool to add thickness to the design if desired. Alternatively, you could create your design in a 3D modelling software like Blender and then import it into Fusion 360 for rendering and analysis. This will give you more freedom to create the exact product prototype & design you want, but you may need to sacrifice some of the accuracies of the analysis tools compared to what you could do in Fusion 360.

[TheCADWhisperer]

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@miantonio wrote:

Alternatively, you could create your design in a 3D modelling software like Blender and then import it into Fusion 360 

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@miantonio 

Can you Attach an example?

[rfCY4KH]

Hi, Mark -

I am attempting the same thing you are but am getting hopelessly stuck, even when I sketch new bend lines on my tabs -- self-intersecting, etc.

My question is: once you have bent your tabs inward, how far away from the original bend line do you sketch the new bend lines? Nothing seems to be working for me.

If only there were a way to set the bend so that it automatically placed the tabs side by side. There may well be, but I can't seem to find what or where.