Cannot explode a single surface?

Rhino Rhino for Windows
1

I downloaded a gear from Grabcad. I exploded it and got this. I really just wanted the outer ring and thought it would explode further with the fillets being separate parts. It would not, and I get the error, “Cannot explode a single surface.” I was unaware a object like this could be a single surface. I’ve actually gotten what I needed, but have two questions for my own edification.

  1. Can such a surface be broken up?
  2. How does one build a surface like this?

gear
gear880×1021 211 KB

ring.3dm (1.9 MB)

2

Hi @CalypsoArt,

Run the What command and you’ll see that its a single surface with many trims.

– Dale

3

Re 1. –
Re 2. Make a profile curve and revolve (and trim the rest):

image
image962×518 16.1 KB

// Rolf

4

Use _divideAlongCreases with SplitAtTangents=yes

image
image1376×726 93.8 KB

5

Hello - that is a trimmed revolved surface. Use DivideAlongCreases > SplitAtTangents=Yes and then explode.

-Pascal

6

Okay that was easy but how about the attached surface. How on earth this could be one surface…? and how come I can’t model it in plain rhino…:slight_smile:OneSurface.3dm (106.3 KB)

7

look at the degree of the surface, in V direction is degree 1. I think it was made using Loft and adjusting control points later.

8

So you’re saying first loft simple curves and than merge multiple surfaces into one…?

9

How on earth this could be one surface…?

That was what I wanted to know. I guess the revolve would do it.

10

this is a quick example how you can make those shapes

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image1510×797 92.7 KB

11

Thanks Diego. I’m already experimenting with a few new idea based on what you just presented. This is something I am well familiar with but never considered going this far with it’s implementation. Very glad I posted this question…