Rhino Unfolding

**JT Fox** · #1 12-21-2009, 07:30 AM

While playing with Rhino and trying different ways to model wings and then unfold them I came across this message.

"Unrolling doubly curved surfaces will produce inaccurate results."

I've tried to find a way around this and have come up with 2 options.

1) Install a plug-in to do the unfold, cost $200.

2) Re-design the shape.

The first is not an option and the second is a compromise on the shape of the model which I don't want to do.

Anyone got any other options?

Cheers JTF

**Alcides** · #2 12-21-2009, 10:12 AM

Uh oh ... well in my experience the only way is the 2 option.

The point is the paper can't be bend in 2 directions, you can do a cylinder but not an sphere. So the surface has to be "developable".

if you have a doubled curved surface this is impossible to emulate in paper because you cant bend the paper in 2 directions. You need a simple curved surface.

I do not know the plug-in you mentioned but you should ensure that the result is useful in paper.

Maybe if you put a picture some designers would give you advice how simplify the surface.

Regards
Alcides

**JT Fox** · #3 12-29-2009, 01:39 PM

Thanks for that explanation.

I split my shape into more parts and then created the surface from the new edges.

The general shape is still there but it now unfolds.

Cheers JTF

**JT Fox** · #4 03-21-2010, 03:21 PM

I could use some advise on how to design a nose of an aircraft, see picture.

It looks fine but does not unfold. "Unrolling doubly curved surfaces will produce inaccurate results" message.

Any tips on how to re-design this shape so it will unfold.

Thanks JTF

**Alcides** · #5 03-21-2010, 11:03 PM

Do you refer to the "petals" ? If that is the case Could you post a cross section of the nose? I'm asking because it don't look circular and if I'm going to try to help the origin of the petals is very important. Just the curve.

**Dragos** · #6 03-22-2010, 08:22 AM

you could save it as 3ds file and unfold it with Pepakura Designer

**JT Fox** · #7 03-22-2010, 10:13 AM

Attached is the front view.

Dragos.

Exporting to Pep worked but it was a very untidy unfold even after I player around with the edges. It ended up with 16 parts. Too many for a 1/72 nose, in my view, I would prefer 8.

Cheers JTF