How to Create 3D Models for Printing

Bringing a 3D print to life requires a solid model, and there are many factors to consider. We sat down with Scott Newcomb to dive into all you need to know before creating a 3D model to make sure you get the perfect results. 

The first step in this journey? Choosing the right software. The options are diverse – Blender, Rhino, Solidworks, TinkerCad – but the choice hinges on understanding the underlying concepts: Polygons versus NURBS, and the types of modeling – solid and parametric.

The Basics: Polygons vs. NURBS

In the world of polygons, it’s all about connecting the dots. Imagine placing points and nodes on a grid and linking them together. Polygonal modeling deals exclusively with straight lines. Think of it as digital origami. When creating round shapes, the limitations become apparent – the facets are visible. However, these are the files 3D printers understand. You can add more facets to smooth out the appearance, but beware of the trade-off with file size. Scott recommends Blender, a favorite in the maker community for its free and open-source nature.

NURBS (Non-Uniform Rational B-splines) take a different approach. They allow for the creation of smooth curvatures and can be scaled up without revealing any facets, thanks to their high resolution. Once converted to a polygonal format for printing, the smoothness remains intact as long as the file is exported at a high resolution. Rhino and Solidworks are champions in this arena, though they differ significantly in their approach to modeling.

“If you’re designing a Gameboy with a Mario game, the person designing the device to make sure it feels nice in your hands would gravitate toward designing with NURBS. To make Mario, you’d use polygons” – Scott Newcomb

Solid vs. Parametric Modeling

In solid modeling, objects are exactly what they appear to be. Create a cube, and it’s just that – a cube. You can perform operations like ‘boolean’ (subtracting one shape from another), but there’s no turning back. Rhino, with its extension Grasshopper, adds some flexibility, but it’s not inherently parametric.

Parametric modeling acts like a time machine. It allows you to make changes at any stage without altering the final product. It’s about setting relationships – ensuring that components fit perfectly. Solidworks exemplifies this approach. Imagine designing a Discman with specific hole dimensions. In Solidworks, the dimensions are locked; changes don’t ripple through the entire design, maintaining integrity while allowing flexibility.

From Model to Print

Once your model is ready, the transition to printing begins. This step requires consideration of resolution – the finer the polygon meshes, the smoother the curvature, and the less visible the facets. It’s a balancing act between file size and aesthetics.

Choosing the right software for 3D modeling is crucial. Whether it’s the sculptural freedom of Blender, the precision of Rhino, the engineering prowess of Solidworks, or the simplicity of TinkerCad, each has its strengths. The choice depends on your project’s needs – the smooth curves of NURBS for ergonomic designs, the polygonal precision for intricate details, or the robustness of parametric modeling for complex, evolving designs. In the end, it’s not just about creating models; it’s about bringing ideas to life.