Unroll eggshaped surface

Rhino
1

Hello!
I have made this weird eggshaped lampshade for a client. It was supposed to be 3d printed but now the client wants to try to make it from laser cut metal sheet.

Screenshot 2022-03-25 094516
Screenshot 2022-03-25 0945161504×1314 246 KB

So I wanted to know if there is a way to unroll this surface.
I am getting really weird results

Thank you

2

How are you envisioning going from a cut flat sheet to that shape? Like, what kind of metal forming process will be used?

3

Im not really sure but I think it will be hammered into this shape. The client has a lasercuter and a cnc machine and some other tools but he didn’t specify what process he will be using, he just wants a flat version of it.

4

I find it really dumb and defeats the purpose of the original design (playing with the translucency of the fillament) but what can I do? I´m really at a loss here

5

Hello
It is not a simple task. One strategy is to make a mesh of this object. Then suppress all intern points and just triangles. It could be flattened but you ll have to cut all loops that can’t be flattened
https://www.grasshopper3d.com/m/blogpost?id=2985220%3ABlogPost%3A1660067

As the shape in convex there is no overlapping.

1 Like
6

Thank you, this seems to be a promissing solution.
I will try this process and get back to you

7

Send me your file, I can have a look and test that with my tools.

8

lamp branches.3dm (16.0 MB)
Thank you very much for your help!

9

Uh…your client needs another idea. If that thing is only 400mm tall, trying to laser cut that from steel and ‘form’ it is…that’s nuts. It would need to be redesigned with a bigger pattern that’s broken into sections that are meant to be simply rolled together. Or cut by hand out of a formed steel egg. Or something…

2 Likes
10

I also think so, but this is supposed to be a table lamp, so I can’t make it much bigger than it already is. Lets see what my client comes up with.

11

It’s really nice - how did you achieve this trim?

12

Hello
here one first try that seems to work.

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I made a mesh without inner point. I hope it is true I didn’t carefully check. I first use the Rhino RenderMesh that I put in my own tool to suppress inner points.
For the flattening

  1. I tried IVY that is able to make a graph but it can’t flatten the mesh as it is too big, @nejur have you a tool that can flatten a big mesh ?
  2. I tried also Mesh Unroll from OpenNest without success.
  3. So I had to redo my own tool from scratch as there are loops in the mesh. It was quite difficult because little errors are hard to detect and I didn’t do such thing since some years. it was a good exercise for the brain.
    So you will see random cuts in the mesh.
    You will see overlapping, so you’ll have to cut the mesh is special parts in order to be able to not have missing part.
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eggLampFalttened.gh (8.1 MB)

I think it is doable for a good welder with some egg shape in order to bend the shape nicely. Please show us the result and don’t hesitate to ask other questions.

It could be possible to change the first flattened face, so it changes the shape.

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Another way of doing is laser cutting the egg like Greg Blanpied
https://www.instagram.com/p/CbLb7dGO1dK/

3 Likes
13

Thank you!
I used parakeet for the pattern then intereceted it with the eggshape and interpolated curves on the surface to create a clean cut on the surface! There are probably quicker ways but this was the only way I could think of.

14

Thank you so much!!
The laser cut verion also seems really clean and good

15

might also work with a rotary cnc

1 Like
16

intresting but doesnt seem to work with metal.

17

why not? i dont see any reason such a device could not also work on metal. metal would be even slower for the drill head, so that should not be an issue. but i am not a specialist just had this idea and looked for some matching video, maybe not that exact machine (but then again why not) so i am pretty sure that could work.

18

First of all the description of the video you sent me specifically states the following:
“- Use on hardwoods, softwoods, exotic woods and many synthetic materials such as acrylic, and ABS, foam, modelling wax, styrene and epoxy board.”

Usually you can’t use the same sort of drills for metal and wood.
I am also no expert, but usually this is how it goes - If a wood tool doesn’t say it will work with metal it probably won’t.

19

are you talking about the tool tip? the drill or however one would call it in english? no that of course will not be the same, but the machine can do that pretty sure, it does not need more force, rather less since it will drill slower. but whatever i am sure you will figure it out how to produce that fabergé :wink:

also as replied, that was just a random example i picked to show the idea, there are different machines of course.

20

To cut is one thing, the metal would naturally not want to bend. And the forming technique also requires material to change and elongate in multiple directions where 3D software cannot simulate or guess… CNC such shape can also be super challenging as of the size. 3D printing might be good way?