Folding paper or cardboard into a rounded shape

macdony_denis

Hi all,

Usually I fold cardboard using the rotate feature with each extrusion.

This is the easiest way I have found when the folds are straight.
https://cad.onshape.com/documents/9868b15118620477878e9ba8/w/6b182f1d99f44145e27058e2/e/17bce658314676f33e3ca108

There I am stuck because the folds are rounded and the cardboard must warp like in the photo in the file.
https://cad.onshape.com/documents/f9d844de4dda81f7481009fd/w/0ede7447e19d51a8d558e1a8/e/a14c380f6703c2798b529efe

Thanks for your feedback,
Denis.

john_mcclary

You could use a loft here

macdony_denis

Hi John,
I do not understand.
Or you forgot to put a link ...
Thanks for your feedback.

macdony_denis

Hi,

I found "loft", ok, thx.

But I don't see how to use it in my case.

In loft1 I put "face of sketch1" in "profile" and the 4 "edge of sketch1" corresponding to the 4 curves for the folding.

But it does not work.

In loft2 I tried with "path" but it doesn't work.

If someone could give me a similar example.

Thank you.

Denis

john_mcclary

I'm not an expert in lofting, but I was hoping for a loft surface between the red and blue edges, then thicken.

You may need to put a slight flat on each end point where the red and blue meet.

macdony_denis

Hi,

I can't do it :(

I created a "sketch 3" with a curve that can serve as a guide, but that doesn't change anything .....

EvanReese

is this perhaps what you're going for? (Link). if this is something you're planning to do more of, you should explore the sheet metal tools, which can also produce a flat pattern for you. I've designed packaging with it before.

EvanReese

I added a super quick sheet metal example to the same link above, in case that's of interest.

romeograham

I think this is a curved bend of the type that is common in the bottom of french fry containers, so is something like this:

This is really just a simulation of what this part would be like in its "folded" state - with the curved fold, Onshape can't treat this like sheet metal, and won't be able to give you a flat pattern. Here's a way to simulate the flat pattern by using the Measure Value custom feature script to get the length of the folded flap - then use that value (as a variable) to correctly size the flattened flap:

You can see how it's built here: https://cad.onshape.com/documents/1af71d2dd62160be757d3243/w/ec0b5df8025976633d7559fc/e/d0a0192b9407121b702af599

Another very useful Custom FS in this model is the MultiMirror FS, made by @Evan_Reese .

Good luck!

Romeo

macdony_denis

Hi,

Thank you all for your help...

Now I have to understand how you did it.

Denis

macdony_denis

How to select all "Edges of Sketch 1" in "Split" ?!

When I select with a window, it adds each segment in the list and not just a group of segments.

And the result is bad.

Evan's "Split" model

macdony_denis

Or how to put a Sketch on a rounded surface ?!

it could be easier ...

EvanReese

@macdony_denis select the sketch from the feature tree itself, and Onshape will sort it out.

There's no way to have a "curved sketch" but for most situations either using split on a surface like this, or using projected curve can get you what you need

macdony_denis

Thank you very much Evan, I will look again 😉

macdony_denis

I succeeded with 8 "Transform" but the folds are not very beautiful 🙄

EvanReese

I'm curious, what's your final purpose? Are you manufacturing these? if so, just 1, or 1000? or is it for renderings, or 3D printing, or something else completely? The goal can inform modeling decisions a lot.

macdony_denis

This is for the renderings.