This shape has me stumped

I’ve gotten pretty good at figuring out complex shapes - my latest conquest was a pleated seat for a race car - but this bugger has me stumped. Basically it’s an air intake into a carburetor - three intakes that merge into a quasi-oval. It wouldn’t be so bad if the intakes were round at both ends, but two of them go from round to half-moon, and the one in the middle more or less goes from round to rectangle. Any suggestions on how to go about this will be appreciated.

Well, I would start with making the inner volumes, then offset those and use the offsets and their intersections to model new surfaces.

The inner surfaces I would make from sweep2 and evolve them into networksurf if needed. I imagine it would be a few iterations before you are happy.

What do you need the model for? Production or just visual representation?

3d printing. It will be 1/24 scale so I’m not concerned about the internal shape - solid would be fine if that’s easier.

Although I’ve gotten good at doing some complex designs, I’m still a bit of a novice - not real familiar with sweep2 or networksurf. I’ve used them, but not enough to be familiar.

You can not work in Rhino with out them, that just doesn’t make sense, so read up :wink:

Here is a test for you, on the left one I made every surface seperately, but that gives sharp edges, so on the right one I used closed curves and used the rebuild (with 10 as value) function in sweep2 to get smooth edges. Not perfect, but maybe good enough for print. You can turn on controlpoints for the surfaces to fine tune them. Then add caps to close them so they are solids.

The red curves are simple, “handmade” curves with 4 points to control their direction, so they are easy to manipulate. You need to adjust their points to get the correct height of the pipes.

Note that the circles are split and rejoined. Not sure if it was necessary here, but that often gives the commands some aid in controlling the flow.

A beer can be sent to my home adress :wink:
Good luck!

manifoil.3dm (755.7 KB)

Thanks - I was trying something like the one of the left but using curve network with les than stellar results. This looks like a more promising route :smiley:

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