docs/02_module-1-what-is-3d-printing/03_3d-printing-facts-concepts/02_how-3d-printers-work.en.txt

[MUSIC] Now that we've discussed
the history of desktop 3D printing, let's examine how these printers work. The most existing manufacturing
technologies, such as CNC machining, create objects by starting with
a large block of material and using a tool to cut pieces away until
you're left with the object that you want. In contrast, 3D printing is
an additive manufacturing process. Instead of subtracting away from
an existing piece of material, 3D printing starts with a blank slate and
then adds materials to it. This additive process is
driven by a microcontroller, which guides a set of motors that moves
a print head in three dimensions. The movement of this print head is guided
by a digital design file which is read by the printer's motherboard. As the print head moves, it softens or hardens material in an additive manner
from either the bottom up or the top down. Although all 3D printers imply
additive process are actually several different types of 3D
printing technologies. The additional resources page will
describe these various technologies in more detail. So, I'll just focus on the three types
of 3D printing that are currently or will soon be affordable for
the desktop user. The first is the process known as SLA or
Stereo Lithography. Now this was the first 3D printing
technology, and SLA creates objects by using a beam of high intensity light,
such as a laser, to harden a soft resin. Let me give you a demonstration. So I have this laser pointer,
and to simulate resin, I have a container filled with dish soap. So essentially,
the SLA technology works by shining this laser on the resin in a successive
manner until an object is built. SLA creates small objects that
have really high resolution that prints as low as
25 microns per layer. However, these objects
are not very strong. So SLA's a good technology for
making jewelry or small display objects
such as chess pieces. A good example of a desktop SLA
printer that's currently available is the Formlabs printer
which cost around $3,000. The second technology is a technology
known us SLS, Selective Laser Sintering. Now this technology has
some similarities to SLA, both use a high intensity of light. However, instead of hardening a resin, SLS printer uses light to
center a powdered material. Let me demonstrate. So again, I have our laser pointer,
and instead of having resin, we have a container filled with,
in this case, powdered sugar. We imagine this could be anything,
powdered metal, for example. And using the laser, which we'll move
over the powdered material left and right, up and down, and then a print
bed will move it or move it down. You'll have a 3D printed object. SLS printers create objects that
have both extremely high resolution, as low as 10 microns per layer,
but are also very strong. These printers are capable of also making
objects from a wide array of materials, including metals. So SLS is a good technology for creating precision objects that need to be
strong and durable such as airplane parts. At this point, there are really
no true desktop SLS printers, the closest thing is the blueprinter. This printer employs SLS for plastics,
but won't currently print metals. The blueprinter costs about $30,000. It's a bit higher than most desktop
printers, so it's not quite home ready. However, many experts believe
that a lower cost version of an SLS printer is
only a few years away. The third and final example is FDM,
Fused Deposition Modeling. FDM is, by far, the most common
form of desktop 3D printing today. Now FDM, which is what the Ultimaker is,
creates objects by melting filament and extruding it through a small nozzle
that moves in three dimensions. Let me demonstrate with
this spool of twine. So imagine this is the filament,
this twine and the printer is melting it and
layering it in a successive manner. FDM printers are capable of making
moderately-sized plastic objects that have good but not great resolution. Typically, these printers print about
as low as 100 microns per layer. That's about it. So at this time,
this is a good technology for making objects that have to be fairly
strong but don't have to look perfect, such as replacement knobs for an old
appliance or homemade toys, for example. The Ultimaker is a good example of
a portable desktop printer which costs, again, about $2,500. [MUSIC]