Help - Advice on how to find the logic to build this shape

Rhino Rhino for Mac
1

Hi. First of all I want to apologize cause I already post questions about this model. I learn a lot with it. Still I am getting super frustrated cause I want to make a render with it…and I would like to have it as ‘clean’ as possible in order to export it to Modo to make the uvs.

I know there is not a ‘better’ software, but maybe there is something where someone with my knowledge can solve it faster. So once you read the topic, if you believe I can get done the model in another software I would like to be aware of that. I am also building it with a CNC. The reason why I want to be so thorough with the model is cause I want to learn from it.

This is what I built in Rhino:

RHINO_MESS
RHINO_MESS994×1006 383 KB

As you can see the model is extremely dense and ‘messy’.

The method:

  1. Polysurface (with filleted edges).
  2. Oblique planes to intersect the polysurface ----> Outcome used as rials
  3. 2 profile curves for each sweep2.

Moi_2
Moi_2969×1031 167 KB

I am trying and learning by recreating the strips with more profile curves and reconstructing the rials. I am not sure why, but Intersection curves are extremely dense.

This is a sample of my way, I am sure this IS WRONG:

Strips
Strips1023×976 420 KB

Well, first…it is extremely tedious to make each surface re-building every curve. Still taking aside that aspect…I need to match every contiguous surface and when I do that…the strips start to have gaps between them. When I join one entire ‘loop’ to the next one I have naked edges.

I even sent an email to Mcneel to talk with someone that can explain me the ‘logic’ to build this under the ‘correct’ way , or at least the less problematic. They answered that I should post on the forum.

If anyone have the time. I can even pay a class, online talk…I really want to understand how to build this.

My idea is to export it afterwards to MODO in order to make the UV . I can not do that in Rhino for Mac.

Thanks a lot, and hope you can give me a hand.

2

We’ve been looking at this many times.

The general problem here is: You want to model the surfaces that a ball-nose cutter would create mechanically when CNC-milling this object. The strange “lid shape” you have on top makes it particularly difficult. With Rhino’s tools, you can only get so far. With Catia, Alias or particularly SolidWorks, it would be far easier. You would draw the ball-nose cutter’s tool paths, convert them into adjacent “sausages” like some other user explained to you, then intersect them all.

I would just render it as it is and retouch the glitches in Photoshop.

But then, you will receive the finished model from CNC-milling anyway, then you are able to photograph it, so why even bother?

3

Thanks Lagom. I very much appreciate your help. I was just wondering if someone could give a feedback. I feel when I post it, it got very much into the CNC thing…I am not trying to solve the technical part of how the thing will be done in real life. We solved that. I am trying to get a feedback regarding Rhino principles and how to build certain shape.

The time I posted the topic ( the one where you kindly participated ) I did not receive enough rhino theory, but much more about how the CNC will do it. That Is not what I am looking for.

Again , I do not want to sound ungrateful. Now I am trying to learn or understand a shape and how to build it properly.

Regards

4

Let’s understand again:

  • The shape you want to model in 3D is a shape that looks that way, because it is 3D-milled by a ball-cutter
  • Thus, you need to find 3D modelling tools in Rhino that let you do with surfaces what a ball-cutter does in machining
  • These tools do not exist to make it straightforward
  • Closest with what Rhino can do would be the „sausage“ method, shown by another user, who instantly understood the connection (I can’t remember who it was, you can dig it out)
5

I am not sure why the ‘ball cutter’ is a concept here. I am making a sweep two rails between a blend curve (poisition-tagency) and another one (position-position).

Hope this helps