KAMRI: Hey guys, it's Kamri.
Our school just got some 3D
printers and Nat Geo let me
borrow one to figure
out how they work,
but to be honest, I've just been
using it to print tiny cats.
It's like a tiny
printed cat army.
Cute, but no idea how
idea how I made them.
These printers look
super complicated.
You know what?
I'll just print an
expert to help me out.
CODY: Hey Kamri.
I'm Cody Goldhahn, mechanical
engineer and Nat Geo expert.
KAMRI: Wow, that
thing really works!
CODY: What?
KAMRI: Uh. Nothing.
So, Cody, can you tell me
how a 3D printer shapes
things so perfectly?
Is it like a robot sculptor?
CODY: Not exactly.
A person who sculpts stone
removes chunks of the stone
until it is in
the desired shape.
That's called a
subtractive process.
A 3D printer does the reverse,
it's called an additive process.
This means that the printer
starts with nothing and then
adds just enough
material to make
the same shape as a sculptor.
It wastes less material than
traditional manufacturing.
KAMRI: It looks like
it's icing a cake.
CODY: Yup.
It's just like a whole bunch
of icing layers on a cake.
A really hot extruder nozzle
squeezes out liquid plastic
layer by layer right where the
computer program tells it to.
Once the layer is done the
extruder raises up just enough
for that next layer to
get squeezed out on top.
KAMRI: Can a 3D printer
print with other stuff?
CODY: Oh yeah!
You can print with plastic,
ceramics, glass, metal.
Some scientists have even
found a way to print with
biological tissue.
KAMRI: Wow, kinda
like how I printed you.
CODY: What?
KAMRI: Uh, nothing.
CODY: The possibilities of
3D printers are endless.
There's many different shapes
and sizes of 3D printers.
They can print houses,
dental implants, complex
bridges, even pizza!
KAMRI: Printable pizza!
That's so cool!
So, how does the printer know
how to print the exact shape
of my cat toy?
CODY: Think about you and your
computer as the toy designer.
You draw the blueprint of
anything you can imagine with
your computer,
creating a digital model.
The computer then looks at
your digital model and slices
it up into layers, just
like the icing on the cake.
Once it knows right
where to put the icing,
it tells the printer to
squeeze out on that exact spot
until the whole model is built
just like your blueprints.
KAMRI: Wow, thanks so
much for your help,
Cody, you truly
are one of a kind.
CODY: Hi Kamri.
I'm Cody Goldhahn,
Mechanical Engineer.
How can I help you?
KAMRI: Uh, I didn't
know you had a twin?
Now that you know
how that works,
catch up on all the other
episodes of How Things Work
by clicking right here.
And also make sure you
subscribe to Nat Geo Kids
by clicking down here.
See you next time. Bye!
Captioned by Cotter
Captioning Services.
