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/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] |