A VERY, VERY BRIEF INTRO TO 3D PRINTING:
Industrial 3D printing has been around since the 1980s. The technology became available to hobbyists and
consumers in 2009 when the RepRap Project brought together thinkers and coders from around the world
to create freely open plans and software. This gave anyone the ability to build a personal 3D printer, such as
the example shown in Figure F-2.
Fast-forwarding to today, the 3D printing industry (industrial and consumer combined) is now estimated at
around $17.8 billion and is expected to be $23.9 billion in 2022 and $35.6 billion in 2024. In the first edition of
this book, published in 2016, we cited the global 3D printing market was around $6-$7 billion; that’s a lot of
growth in 4 years! No one has a crystal ball to know the future, but it seems certain to us that 3D printing
will increasingly affect the way we as a society design and manufacture physical items.
HOW 3D PRINTERS WORK
Now let’s dive into the details. The most common type of 3D printing is known as “additive manufacturing” in
which small amounts of material are slowly built up into an object. The primary method of this is called FDM
(fused deposition modeling) or sometimes FFF (fused filament fabrication). FDM printers create objects by
building up material layer by layer over time. A thin strand of filament feeds into a part of the machine called
an extruder, which melts the plastic at a high temperature—typically around 200°C. There are many other
methods of 3D printing that this book will cover in later chapters, and they all work in the same “additive”
way. They bind, melt, or photo-polymerize (liquid resin which is hardened with UV light) material together to
create physical geometry.
The FDM process is very similar to using a hot glue gun. You probably have one at home and have used it for
craft or school projects. When you squeeze the handle of a hot glue gun, the solid glue is pressed against a
heating element and soft, spaghetti-like strands of molten glue extrude from the nozzle. Imagine swirling
those strands around and around on top of each other, forming circles that build up into a tube. As the glue
cools, it hardens, and a tube is created.
Following the glue gun analogy, in a 3D printer a thin strand of melted plastic is programmed to deposit
down, layer by layer, on a flat surface known as the build plate, where it cools and hardens into an object.
The 3D printer knows precisely where to trace each layer through instructions in a digital file sent from a
computer. The image in Figure F-3 provides a closer look at how this technology works.
Most consumer 3D printers use FDM technology and have a large spool of coiled plastic called filament
attached to them.
FIGURE F2: An early example of a person assembling a 3D printer from a kit.
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