How to unfold a model?

[daverio.jonas]

I am trying to "unfold" a surface to have a 2D pattern to work with.

What I have basically is prism extruded from an airfoil and I want to have a 2D version of it to make it out of paper.

It is a really simple unfold to perform (no deformations) because all faces are flat and every fold is straight.

Here is it :

[g-andresen]

Hi,

I don't think there's anything to unfold.
You determine the stretched length of the profile and the lenght of the Wing, that‘s all.

günther

[daverio.jonas]

The problem is that the faces are not rectangular and that there are holes
in them.

I saw the program ExactFlat but it is very expensive. Maybe I can do it on
a different program. Or I might unfold manually every face.

How would you do it?

[davebYYPCU]

Fusion will do it, with some preparation.

Fold and unfold is limited to sheetmetal Components.

Fold and unfold must be cone or cylinders, or parts thereof.

So trace the airfoil with arcs that are tangent with no loop connection.

You can then add the length of the arc / lines together to draw @g-andresen ‘s Solution, or 

making sure there is one flat surface unfold the flange.

Might help....

[daverio.jonas]

I'm not sure to understand what you are saying.

To be sure that we understand each other, my airfoil profile is a simple
polygon, and the sheet (which is a model and not a sheet) is a prism with a
negligeable and uninteresting thickness. I then made cuts in it from other
bodies, and I want to know precisely where they are going to end up.

In addition, the edge is not at 90°, which shall result in a wiggly and
somehow hard to predict 2D shape.

[davebYYPCU]

Your description does not match the picture.  I did not see a polygon in that airfoil.

I described how to make a flat pattern with Fusion tools, that represented that pictured wing.

So think we are both confused.

Fusion flat pattern will do faceted plates even easier, than the curved version.

[daverio.jonas]

This is how the airfoil profile looks like :

It is a simple polygon with straight edges. I then outset it (you see, by 0.1mm) and I extruded the outside to represent the sheet. I could also have done it in patch mode to have a just a surface. But I don't see any option to unfold it or to 2D pattern it as you mentioned.

I have to make cut in it from other bodies and to see where those cuts end up at the end.

[davebYYPCU]

Ok, it's a (complicated) polygon.

Take your airfoil to Sheetmetal.

Then Flange for each line will give you the model, Flat pattern will do what you need.

Might help....

[daverio.jonas]

What do you mean by "take your airfoil to sheetmetal"?

[davebYYPCU]

I have done a top half for the demo, 

1.  Your sketch exists in the file.

1A. Change to Sheetmetal.

2 Create a new Component and activate it, 

3. Create a Sketch and copy / paste or project the airfoil lines into this sketch.

4  Create a Flange on each line.  I did the four big ones, one is blue to show it is a separate face.  When all are done.

5. Cut the bodies with your cutting bodies, 

I tested the Flat pattern as listed in the Browser.

Might help....

[daverio.jonas]

Ok, now I get your point. I tried it, but I don't know how you could create a flat pattern out of several bodies. I could only if I made my sheet in one body, by selecting all line at once, but I couldn't select them all because it was causing some errors. If I made several bodies, the flat pattern would concern only one body.

[g-andresen]

Hi,

You need to „join“ every new body to the previous ones.

günther

[TheCADWhisperer]

File>Export and then Attach your *.f3d file here.

[g-andresen]

Hi,

here´s a model with cut outs.

regards

günther

[daverio.jonas]

There is no option to join a flange on my version:

[TheCADWhisperer]

Can you File Export and then Attach your *.f3d file here?

[daverio.jonas]

I just posted a long message explaining what went wrong and everything was deleted. I hope this will work this time.

Here is the archive. As you can see, I had to do several ugly things.

First, I had to redraw the profile with a fit point spline because Fusion wouldn't flange if the angle between to line is less than 1° (WTF).

Then, I had to flange it long enough so that it could intersect the planes "ProfilMilieuGauche/Droite" ("Left/RightMiddleProfile"). I could then do a split and remove the part on the sides. I find it very ugly and it would have been much more convenient if there was the same "To Object" extent option as for the normal extrude.

One more ugly thing I had to do was to add a point very close to the point at the tip at the back of the profile, so that I could make the spline line not closed, because otherwise, it would do a very ugly bend at that point, and it wouldn't have fit precisely enough the profile:

One more downside of the fit point spline is that the flange doesn't fit the profile well enough anymore, causing the cut I had to make not precise enough:

As you can see, there are two different faces, distant by about 1 micron. The tool body touch the sheet where it shouldn't, it should be perfectly tangent to it. That cause a big performance issue as it crashed everytime where I performed a flat pattern. It didn't crash before I made the cut.

Strangely, it worked with the other body:

As you can see, the face remained connected (not simply connected because of the hole) and the hole circled in red was at the right place.

[daverio.jonas]

I totally abandon Fusion on that point. I solved my problem that way:

I extruded the profil in patch mode. I exported the body in STL and I imported it on Blender. There is a pre-installed plugin called "Export Paper Model" that does exactly what I want. If someone is interested, there is a tutorial here.

Thank you all for your support, and if you find a solution in Fusion, please let me know.