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3D Prin(ng
Turning molten plas(c into neat toys
3D Prin(ng
• Lots of different kinds of 3d prin(ng • Some use powder, metal, etc. • Primary home/hobby prin(ng is “FDM” – Fused Deposi(on Modelling – Basically: A glue gun controlled by a printer – Assembly is layer-‐by-‐layer
Models: Makerbot
• Consumer-‐targeted 3d printer
• Designed to be ‘no setup’; easy for consumers
• Costs about $2200
Models: Printrbot
• Originally kickstarter • Typically sold as kits (but can buy assembled for $100)
• Varies in cost from $300-‐$800
• Targeted at hobbyists.
Materials
• PLA – Biodegradable – Produced from corn – Lower mel(ng temperature (compared to ABS)
• ABS – Higher temperature – Higher mel(ng temperature
• Can print in other things (teflon; nylon; wood filament) – much less common (and more expensive)
Costs
• “Filament” (plas(c 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 plas(c
What can you make?
• Just about anything plas(c 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
How it works: Sodware
• 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 plas(c on the insides of pieces so as to not waste material
How it works: G-‐Code • Slicer generates “G-‐Code”
– a set of “move here, at this rate” instruc(ons
• G-‐Code was originally designed in the 1980s for driving other computer-‐driven manufacturing
• G-‐Code can be interpreted by firmware on the electronics aiached to the printer
How it works: Repe(er
• Sodware to control overall interac(ons with the printer
• Communicates over USB to printer
• Has UI to control posi(on, heat, fan, etc.
• Repe(er also has slicing and G-‐Code visualiza(on
How it works: Prin(ng
• Melts 3D plas(c in a heated head (~200 degrees C)
• Prints onto flat surface – important to get the first layer right so it s(cks
• Motor feeds material through the hot end, pushing plas(c out the other side.
• Motors move the bed and the print head in 3 dimensions to print
How it works: Complex Prints
• Some 3D models can’t be printed without overhangs
• Two basic components: Bridges and support material
• Bridges are connec(ons between two exis(ng pieces of plas(c
• Support material is thin layers designed to form a basis for bridges – temporary, intended to snap-‐away
How it works: Complex Shapes
• Not all complex shapes are complex prints though
• Some shapes with lots of holes in them can s(ll be printed (rela(vely) easily
• Common style: Voronoi surface
How it works: Bigger Shapes
• 3d prin(ng bigger shapes usually works via snap-‐fit or press-‐fit pieces
• Push pieces together to get them to stay
Coolest Items
• Ar(culated excavator: “Liile Digger”, thing:208315
• Prints as one piece • Wheels, cab, and arm move
Coolest Items
• Fidget cubes • Prints as one piece • Hinged • thing:230139
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…
Designing Models: OpenSCAD
• OpenSCAD is 3D Modeling for programmers
• You write 3D models with code
• Can import and export common formats
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)
Crea(ng your own Filament
• Filament extruders can be purchased as kits for a few hundred $
• Take in plas(c pellets ($7-‐$10/kg instead of $30-‐$40)
• No commonly available way to re-‐melt prints currently, but people are working on recyclers
Other types of 3D Prin(ng
• Powder bed 3d prin(ng • Laser sintering • Laminated • Light Polymerized
Things to know • 3D Printers – at least, printrbot – is *not* a commercially ready tool – It requires a lot of (nkering and tweaking to get good prints
– When the answer from support to a problem is “Pull out your mul(meter 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
FAQ
• Have you printed a gun? – No. This is a silly use of 3d prin(ng, 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