Car Voronoi Rim | CAD

Realisation of a parametric rim using a Voronoi structure using Grasshopper

Grasshopper voronoi Rim

The aim of this project was to create a rim from a curve using voronoi structures. By modifying parameters within the code, it is possible to obtain numerous variants of the rim. These parameters affect the subdivision of the generated curves, their position relative to the central reference point and their depth. Finally, a surface is generated from these curves, which is then transformed into a mesh.

The following pictures show step by step how to achieve the final result. The code is not particularly complex, but still needs to be read carefully, especially because of some key steps.

1. Creation of the two concentric circles, with different diameters, oriented according to the XZ axes.

2. Creation of the surface generated by lofting the two circumferences. Extraction of Iso curves from the generated surface, subdivision into n° points and rotation of them by a certain value.

3. After establishing the boundaries, creation of the voronoi structure. Intersection of the two surfaces (loft one with voronoi one)

4. Creation of outer surface by using two curves: ones obtained with the previous intersection an the other ones obtained by using scaled one geometry. Creation of the inner face of the rim using as a geometry the scaled curves and the ones obtained by rotating the iso points in previous step.

5. Creation of inner cylinder. Lofting together the starting curves and the scaled ones. Then transform everything in a meshes and add colours to them.

Final Notes:

In the last three Rhino screens you can see that the rim spokes are a bit jagged, this could be due to: these are shots from Rhino when I already baked different surfaces and there was still something that overlaps and creates a jagged and therefore not very homogeneous effect. Otherwise at prompt level it could be that playing a little with the different parameters, a more homogeneous and not jagged structure can be achieved.

Starting from this:

Why is the disk actually on a linear cone-line surface?

I based the rim on this drawing, in particular the image on the right. It is a side section of a wheel rim. So I thought that by doing this, then creating a loft surface between two circumferences with different diameters was a good approximation for the end result I wanted to achieve. On an engineering level it is definitely not the best way, especially in terms of performance. But I think it is a good approximation

https://drive.google.com/drive/folders/1Uvq8CyBzqiIKpyx0riGl67eizItgmis5?usp=drive_link

(GH code and Rhino starting curve and baked rim)