2. 3D Printing
• Lots of different kinds of 3d printing
• Some use powder, metal, etc.
• Primary home/hobby printing is “FDM” –
Fused Deposition Modelling
– Basically: A glue gun controlled by a printer
– Assembly is layer-by-layer
4. Models: Printrbot
• Originally kickstarter
• Typically sold as kits
(but can buy assembled
for $100)
• Varies in cost from
$300-$800
• Targeted at hobbyists.
5. Materials
• PLA
– Biodegradable
– Produced from corn
– Lower melting temperature (compared to ABS)
• ABS
– Higher temperature
– Higher melting temperature
• Can print in other things (teflon; nylon; wood
filament) – much less common (and more
expensive)
6. Costs
• “Filament” (plastic used as input to the
printer) typically costs about $30/kg
– Can be found as low as $20, but “you get what
you pay for”
• Many small items can be made for 50 cents or
so worth of plastic
7. What can you make?
• Just about anything plastic with enough care
• Limited by build volume (Printrbot Plus is 8”
cube) and layering approach
– You aren’t going to build a car with a 3d printer
very quickly
– You’re also not going to build a chandelier very
easily – anything with overhangs can be difficult
8. How it works: Software
• Take a 3D model (STL file)
• Use a ‘slicer’ to turn it into layered paths for
the head of the printer
• Slicer intelligently fills in solid spaces with
material
– Also tries to minimize plastic on the insides of
pieces so as to not waste material
9. How it works: G-Code
• Slicer generates “G-Code”
– a set of “move here, at
this rate” instructions
• G-Code was originally
designed in the 1980s for
driving other computerdriven manufacturing
• G-Code can be
interpreted by firmware
on the electronics
attached to the printer
10. How it works: Repetier
• Software to control
overall interactions with
the printer
• Communicates over
USB to printer
• Has UI to control
position, heat, fan, etc.
• Repetier also has slicing
and G-Code
visualization
11. How it works: Printing
• Melts 3D plastic in a heated head (~200
degrees C)
• Prints onto flat surface – important to get the
first layer right so it sticks
• Motor feeds material through the hot end,
pushing plastic out the other side.
• Motors move the bed and the print head in 3
dimensions to print
12. How it works: Complex Prints
• Some 3D models can’t be printed without
overhangs
• Two basic components: Bridges and support
material
• Bridges are connections between two existing
pieces of plastic
• Support material is thin layers designed to
form a basis for bridges – temporary, intended
to snap-away
13. How it works: Complex Shapes
• Not all complex shapes
are complex prints
though
• Some shapes with lots
of holes in them can still
be printed (relatively)
easily
• Common style: Voronoi
surface
14. How it works: Bigger Shapes
• 3d printing bigger
shapes usually works
via snap-fit or press-fit
pieces
• Push pieces together to
get them to stay
15. Coolest Items
• Articulated excavator:
“Little Digger”,
thing:208315
• Prints as one piece
• Wheels, cab, and arm
move
17. Finding Models: Thingiverse
• Thingiverse is a 3d model repository that
offers lots of 3d models
• Social – can also share 3d models, share
‘makes’, etc.
• Supported by Makerware
• Good to find first things to print – toys,
puzzles, printer improvements…
18. Designing Models: OpenSCAD
• OpenSCAD is 3D
Modeling for
programmers
• You write 3D models
with code
• Can import and export
common formats
19. Designing Models: Sketchup
• Sketchup – formerly from Google – is another
design tool
• Free plugin to support export to STL
• Can be used as a visual design tool (rather
than code)
20. Creating your own Filament
• Filament extruders can be purchased as kits
for a few hundred $
• Take in plastic pellets ($7-$10/kg instead of
$30-$40)
• No commonly available way to re-melt prints
currently, but people are working on recyclers
21. Other types of 3D Printing
•
•
•
•
Powder bed 3d printing
Laser sintering
Laminated
Light Polymerized
22. Things to know
• 3D Printers – at least, printrbot – is *not* a
commercially ready tool
– It requires a lot of tinkering and tweaking to get good
prints
– When the answer from support to a problem is “Pull
out your multimeter and measure the resistance” you
know you’re in a hobbyist market
• If you buy a kit – expect it to take a while to build
• Bed level is important: Bed level and belt tension
are the two most important aspects of good
prints
23. FAQ
• Have you printed a gun?
– No. This is a silly use of 3d printing, there are lots
of easy ways to build your own gun.
• How long have you had it?
– About two weeks
• Is it made of wood?
– Yep
