What is 3D printing and how does it work?

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3D printing is a truly innovative invention that nothing more and nothing less allows you to create a physical object from a three-dimensional digital model. This advance began in the 1980s under the name of “agile prototyping” as this was precisely the goal of technology: to make models fast and cheap. With this we could already answer the 3d printing question that is. Everything has changed since then, today 3D printers offer amazing results, having the possibility of creating as many things as the human brain can imagine.

How a 3D printer works

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Everything starts from a 3D model on the computer, basically you can create it yourself from 3D modeling software (requires advanced knowledge of the software) or download it from a 3D repository, these files will basically be the ones that feed the 3D printer, with precise indications about the coordinates that must be processed to create the object and that most of them are entered into the printer by means of USB by means of a pendrive or memory, although there are also other types of 3D printers that accept a direct connection to the computer.

3D printer history

Actually the beginning of 3D printing was in 1976, just when the inkjet printer was invented. This concept evolved over time, going from the use of inks to printing using materials such as plastic. In the following list I will share a simple but interesting timeline with the main 3D printing innovations within the industry:

1984 Welcome SLA

Stereolithography or SLA is invented thanks to Charles Hull.

1987 Invented Selective Laser Synthesizing

Carla Deckard is the inventor of this system

1988 llega el modelo por deposición fundida

Inventor Scott Crump develops fused deposition modeling

1993 3D injection printing

MIT designs and produces 3D injection printing.

1996 Z Corpration on the market

The company Z Corporation begins to offer the printer based on 3D technology for the first time

1999 A milestone in modern medicine is broken

At Wake Forest University in the United States, the institute for regenerative medicine inserts transformed organs into human beings by means of arterial implants printed in 3D technology.

2002 Wake Forest University promotes the use of 3D technology in medicine

La universidad Wake Forrest crea un departamento de medicina regenerativa llamada el Envision Tec, imprimiendo en esta fecha como uno de sus grandes logros el primer riñón en 3D completamente funcional.

2006 3D printing for all

The Fab @ Home project arises at Cornell University, it was the first multimaterial 3D printer available to the public with open source.

Types of 3D printers


SLA is an accelerated prototype production process. Those who use this printer take quality seriously. With this printer, objects can be generated by means of 3D CAD data files (computer generated) in a very short time. This is a 3D printing process that is popular for its delicate details and precision. Printers designed under this technology produce unique models.

The process is done by converting liquid photopolymers into dense 3D objects, one layer at a time. The plastic is transformed by means of high temperatures, making it semi-liquid, to later harden again with the formed part. The printer builds each of these layers using a laser. Just before each print cycle, a coating blade is moved across the model area to ensure that each thin layer of resin is spread evenly across the object. The printing cycle continues in this way, building 3D objects starting from the bottom up.


DLP is the oldest of the 3D printing technologies, created by a man named Larry Hornbeck in 1987. It is similar to SLA (see above) in that it also works with photopolymers. The liquid plastic resin used by the printer enters a container of translucent resin. Despite this, it is possible to find a marked difference between SLA technology and DLP technology: the light source. While SLA uses UV light, DLP uses a more traditional light source, usually arc lamps. This process results in some pretty impressive print speeds. When there is a lot of light, the resin hardens quickly (we are talking about seconds). Compared to SLA 3D printing, DLP achieves faster print times for most parts. The reason it is faster is because it exposes entire layers at once. With SLA printing, a laser has to remove each of these layers, and this takes time.


FDM is a 3D printing process developed by Scott Crump, and later implemented by Stratasys Ltd., in the 1980s. It uses production-grade thermal plastic materials to print its 3D objects. It is widely used in the production of manufacturing aids, conceptual models, and functional prototypes. It is a technology that can create precise details and has an exceptional strength-to-weight ratio.

Tecnología de sinterización selectiva por láser (SLS)

An American entrepreneur, inventor, and teacher named Dr. Carl Deckard developed and patented SLS technology in the mid-1980s. It is a 3D printing technique that uses high-powered CO2 lasers to fuse particles. The laser sinters metallic materials into powder (although you can also use other materials, such as white nylon powder, ceramic, and even glass).


SLM made its debut in 1995. It was part of a German research project at the Fraunhofer ILT Institute, located in the westernmost city of the country, Aachen. Like SLA (see above), SLM also uses a high-power laser beam to form 3D parts. During the printing process, the laser beam melts and fuses various metallic powders. The simple way to look at this is to break down the basic process like this:

Powder material + heat + precision + layered structure = a perfect 3D object.

Materials used by 3D printers

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Most 3D printers use a thermoplastic material, which is melted during printing, then hardens as it cools. The best known are the PLA and also the ABS.

  • PLA materials: PLA is a thermoplastic, its origin is totally natural and its properties or characteristics are quite interesting for 3D printing. The process is very fast (much more than in the case of ABS), but has the disadvantage that the printed object is less resistant.
  • ABS materials: On the other hand, ABS is known for being a plastic whose main characteristic is resistance to high temperatures, therefore, it is used in printers that are capable of reaching high temperatures. The interesting thing about ABS plastic is that the 3D prints obtained will be made of a very solid, resistant and difficult to break material.

How to make a 3D printer

Here I leave you a very well explained step by step video tutorial on how to make a homemade 3D printer, if you have the interest and the resources it can surely help you.

3D model resources for printing

3D models for printing

In this section of the article I leave you some websites that I have used for my 3D printing projects where if you have the necessary knowledge you can modify them and create totally new projects from these 3D resources.

TinkerCAD Gallery

TinkerCAD is not only a great and simple 3D editor, we can also find a section (called gallery), which offers us a bank of 3D images with the creations of other users and that we can download at no cost. In the staff selection we can find creations such as question marks, house models, miniature furniture and many other interesting things.


Thingiverse is also a free community and – this time it is – specifically designed for the world of 3D printing. They have categories with collections with articles from everyday life, with models of movies and series, decoration products and other elements that will surely be very interesting for you.


TurboSquid has to offer us an image bank of 3D models that are not completely thought for the world of 3D printing. Of course, it is important to know that unlike the options discussed above, it is a payment repository. Despite this, they have many stored models that we can download for variable prices (some free and others that cost hundreds of euros). Similarly, only some of the models offered are suitable for printing on a 3D printer.