Projecting a 3d helix flat

Rhino
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to forum.3dm (193.9 KB)
would like to take object and flatten, while maintaining 3-d properties , dimensions, hole angles. Can anyone help?

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You want to unroll the part so it can be laser cut?

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I didn’t have time to post a possible procedure yesterday. In the attached, I did the following:

  • Extracted a copy of the top surface of your twisted object
  • Used UnrollSrf to unroll it.
  • Used FlowAlongSrf to flow the 3D object from the extracted top surface (in place) to the unrolled surface

The outline looks OK, the holes don’t match completely 100%, but maybe it’s useful. Of course, the holes aren’t vertical in the unrolled part, because they aren’t perpendicular to the surface normals in the original. I don’t know how you cut those when it is flat.

Unrolled.3dm (2.0 MB)

1 Like
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Hi @bob5
Attached is the flattened solid made with a custom tool. However, if you want to bend that object from metal or so, then I would extend the ends with some “handles”, bend it and cut the holes afterwards. That way the material is more homogenous. But that’s just guessing… :wink:
Jess

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Helvetosaur, I apologize but could you save as rhino 6 and resend your file, thx bob

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Jess, I apologize but could you save as rhino 6 and resend your file, thx bob

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Hi Martin, yes want to make the part out of metal, so I want to water jet the flattened pattern and then heat in a form and create the helix. Probably do the holes after the helix is created with 5 axis waterjet. also I’m running rhino 6 thx bob

1 Like
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Nice, post some pictures if you do it this way…

How are you going to align the part after it is bent?

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Hi @bob5
Attached is a V6 version of Mitch’ approach based on the “mean” or neutral surface. I think it is more accurate than my tool, which was actually designed for something different.
FlattenSolid_jM.3dm (3.4 MB)

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after its bent, it will weld to adjacent parts created in model

1 Like
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Hi Jess, looks good, how did you extract the mid surface( group 3) ? And you used group 3 as target surface for flow along?

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ExtractWireframe then EdgeSrf the isocurves of the vertical helix surface.
I rebuild the surface before unrolling, which is not needed if the curves are good.

How many parts you want to fabricate?
The reason I ask is that a form for “warm” deformation will be pretty challenging.
A good blacksmith may do this rational for hundreds of pieces with sufficient precision for welding.
The holes could be drilled manually or milled on a 3 axis CNC machine.
Good luck, Jess

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got it, thank you. I have just one of this part and 10 similar but all different. Also have a expert blacksmith / metal worker. The holes are challenging but I think I will have them cut with 5 axis waterjet after metal is formed into helix