3D Printing Glossary

More commonly known as 3D printing, additive manufacturing (abbreviated as AM) is a process for creating objects by adding a raw material layer by layer, as oposed to taking it out from a larger block of material. Apart from 3D printing, additive manufacturing is also widely refered to as rapid prototyping, rapid manufacturing, and direct manufacturing, although these are terms which describe a specialized production process, and not the manufacturing technology itself. We see additive manufacturing as potentially having a strong impact on the addition of business value for manufacturers over the next decade. Additive Manufacturing is good in situations where we have a high design complexity, we are constrained by a short execution timeframe, we are aiming for a fast prototyping speed and time to market, and where we want to minimize material waste in the manufacturing process.

to manufacturing – machining or milling where we’re taking a solid block of material and we’re removing (subtracting) some material in order to get to the finished object.
Additive manufacturing in opposition is to say forming technologies, like casting or molding.

Traditional manufacturing methods such as injection moulding are well suited to produce very high volumes of parts. However, due to the high startup costs incurred from buying and designing a matrix, for lower volumes (typically between 2,000 and 4,000 parts, 3D printing is a cheaper and more flexible option, as it allows for design changes at any point of the manufacturing process without additional expenses.

3D printers are the machines which create objects through additive manufacturing by layering material until a finished object is created. Operating a 3D printer to satisfactory professional results requires a degree of knowhow because of the large number of variables involved in getting a successful print process: nozzle temperature, heat bed temperature, room temperature, extrusion speed, and platform leveling just to name a few. There are many different brands of printers with the most popular ones being Zortrax, 3D Systems, Stratasys, Formlabs, EOS, Ultimaker, and many others spanning from starter consumer models to full-blown factory machines.

3D modeling is an umbrella term for various CAD/CAM (Computer Aided Design) activities, which involve representing and manipulating an object as a 3D model in software. 3D modelling is the first step in the 3D printing process. A 3D model has to comply to specific criteria such as wall thickness, surface crossover, and others, in order to be 3D printed into a high-quality part. These requirements are what makes 3D modelling for 3D printing a narrowly specialized field within CAD/CAM.

To 3D print an object you need a 3D model. The model itself can be created directly in CAD software, or it can be generated through the use of a scanning device, which scans a physical object to digitalize it and convert it into an editable model. 3D scanners achieve this through various means such as lasers, touch sensors, and others. The collected data from a 3D scanner needs to be compiled in specialized software and further edited by a 3D designer to achieve full accuracy vis-a-vis the original object.

STL stands for Standard Tessellation Language and it is the most popular file format for additive manufacturing and 3D printing. To tessellate something is to break it down into a series of polygons which represent its structure. Once the STL file has been created, the system slices it into multiple different layers and passes that information (in the form of a Gcode file) to the additive manufacturing device, whatever that device may be. The AM system itself then begins creating the object layer by layer, until we have a finished object.

In 1986 Charles Hull invented a process called Stereolithography in which liquid photopolymer (or liquid plastic) held in a vat is selectively cured, by using UV light. The biggest advantage of SLA is the high resolution, precision, and smoothness it can achieve. Though SLA we can make parts with very complex geometries, which you wouldn’t be able to easily make with other manufacturing technologies.

FDM (Fused Deposition Modelling) is a material extrusion 3D printing process in which a thermal plastic filament is run through a heated nozzle which extrudes it onto a build surface layer by layer to create a finished object. FDM is one of the key underlying technologies for most of the consumer additive devices that exist in the market today.