How to get a 3d model?

3D print compatible models

With a 3D printer it is possible to print a physical object with a 3D digital file. But where do 3D models come from?
Whether you are a beginner, regular user or professional, there are different methods for obtaining the necessary files that are compatible with your 3D printer.

3D file platforms

The most simple source is a 3D file platform. These sites share a multitude of 3D models in different categories: decorative objects, toys, jewellery, gadgets, art, fashion, etc.

Designed for owners of 3D printers, these platforms have hundreds of 3D models created by designers around the world. While some of these platforms offer free open-source files, others are targeted at professional use and offer paid 3D files.

Simply connect to the site and download the file to your desktop; then send it to your printer (see the section about starting your first print).

In most cases, the downloaded 3D model is an .STL file, the most popular format for 3D files. Other formats exist, such as .PLY, .OBJ and .3MF.

Here is an inexhaustive list of 3D model platforms:

  • happy 3D: 3D models of spare parts for domestic appliances
  • Cults: all types of models, both free and paid
  • Thingiverse: the largest community of open source models
  • Pinshape: a range of professional models, both free and paid
  • MyMiniFactory: 3D files tested before printing

3D modelling software

For more creative users, it is also possible to design the 3D model of your dreams with modelling software. This method requires some experience, but there are free software programmes which are easy to learn to use.

There are two types of modelling software, also known as CAD (computer-aided design): direct design and parametric design.

Direct: With direct modelling it is possible to design a 3D model from a block. Like sculpting a work of art, the block can be enlarged, broken, pulled or cut.

This type of software is ideal for novices wanting to realise simple forms quickly. Well-known software programmes include: SketchUP, ZBrush and 3D Slash.

Some are even accessible directly on the internet like Tinkercad.

Parametric: This method of design is, as the name suggests, based on parameters. To create the model, values such as length, width, height and diameter are entered into the software, like in a mathematical formula.

More or less complex geometric forms can be created according to the number of criteria used. This technique is the basis for many professional software programmes like SolidWorks and AutoCAD.

Once the 3D model has been designed by the computer, simply save it in the .STL format (or another printable format) and send it to the 3D printer.

3D scanners

A 3D scanner can be used to replicate an existing object without starting from scratch. By definition, 3D scanners can be used to create a 3D model from an existing physical object, just like scanning a piece of paper.

There are fixed scanners with a revolving platform; or manual scanners which you turn around the model to be digitised.

Models on the market feature two main technologies: 3D scanners with laser triangulation laser or structured light technology.

Laser triangulation depends on three elements: a laser transmitter, a receiver, and the object to be scanned. These three elements form a triangle which, by mathematical calculation, creates a geometric representation of the object in the space.

Structure-light scanners have two cameras and a video projector. A grid is projected on to the different faces of the object and the cameras take a series of photos. The 3D scanner software identifies the positions and dimensions of distortions observed on the shape.

Entry-level 3D scanners start at €200 for the XYZprinting model or €450 for the Sense by 3D Systems.

The 3D Sense scanner by 3D Systems

That said, even high-end scanners cannot perfectly create the model of an object. Digitalisation is a solution for avoiding the first steps of creating a model. It is usually necessary to make alterations to a scanned object with modelling software.

And some objects are difficult to scan. This is the case for transparent or reflective objects for example. To facilitate the scanning of such objects, it is recommended to cover them with white powder.