Do I really have to create closed polysurfaces in order to make the file printable/machinable?

The title is pretty self-explanatory.

I mean, Rhino is without a doubt considered the standard (at least from what my university professors say) for marine engineering.

So… how does one go from NURBS complex open poly surfaces to machinable data for CNC or 3D printing?

Am I doing it wrong? Trying to make a closed mesh for STL files for our 3d printer?

I’ve done some Udemy courses, but I feel like I lack the knowledge to go from 3dm to real deal in the correct manner, can someone point me in the right direction?

Thanks in advance.

What are you trying to achieve specifically? A 3D model of a full size vessel won’t necessarily scale to a 3D printable size without modifications. For example a 1:100 reduction will make the plate thicknesses extremely thin for many 3D pritners.

CNC and 3D printing require different information. CNC can generally deal with open polysurfaces whereas 3D printing does require a closed polysurface. Joined polysurfaces are perfectly acceptable for both applications though.

What are you trying to achieve specifically?

I still have a long way to go, but I can mostly achieve what I want to model, however, I would like to learn how to properly model for fabrication using only Rhino3D.

Here go a few examples of what I can face on my day to day once I graduate:

  1. 3D printing 1:10 planning hulls models (I am actually facing that in my internship and has been a hell to get some old models to print - none were made by me)
  2. Machining parts for the creation of molds - so here I face two challenges, making it machinable and making sure it will demould afterward

I have been able to do it, but for 3d printing, I was following an internal how-to that includes using both rhinoceros and Solidworks to generate an STL for then to import into the 3d slicer. The same goes for demolding.

What are you trying to achieve specifically?

Summarizing, I would like to go from model to fabrication without using any other software than Rhinoceros (or the GCode generator tool for 3d print/CNC)

First you were asking about closing polysurfaces, but this is now your request. I’m afraid I don’t know how to help you, which could be a problem with my understanding.

Don’t mix up the processes for 3D printing with CNC, they are fairly different. Both however require a well made model. If you have a model you can share that would be useful.

I don’t think Rhino can perform all the processes required without plugins.

So rhino alone can’t perform all the functions…without plugins or external programs.

CNC doesn’t actually need closed polysurfaces, it’s less demanding than 3d printing. At least for 3d printing you don’t necessarily need to join everything into one part, the slicer will take a jumble of intersecting objects.

All that you’ve dealing with here is “making decent models” and making scale models where you have to make a decent model and discard or modify parts that are too small. It’s not easy if the models are crap that weren’t prepared for it, it’s frankly not a task for a beginner, without specific examples to look at it’s impossible to offer any specific advice on shortcuts.

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