3D-printing basicsCarlo Fonda, ICTP SDUcfonda@ictp.it

From printing (on paper) texts and pictures to “printing” three-dimensional objects

Fused Deposition Modeling (FDM)

• Many technologies are possible for 3D printing.

• The most common one uses molten (liquid) plastic extruded through a nozzle. The nozzle or the object (or more often both) are moved along the three axes X, Y, Z.

• 3D printing is an "additive manufacturing" technique, opposed to the o lder "subtractive manufacturing" machining systems like milling machines, CNC, etc.

Professional 3D printers (10.000$+)

• Pro 3D-printers can print objects

• in plastic, starting from a filament (with FDM), or

• in other material (like metals, ceramics, etc.) provided as powder and “assembled” by sintering (SLS)

• and some are even able to print in full RGB color

• Up to a (very) big size

• Very expensive (“pro” market)

• Beautiful results ;-)

Personal 3D printers cost: from 300 to 3000 USD

Open source + Open Hardware

• Low-cost printers use a plastic filament (ABS or PLA, 1.75 or 3mm thickness) and are usually build with a plywood or acrylic frame

• the software is free and open source: 3D design apps, slicers, printer control apps, etc

• they make extensive use of open h a r d w a r e l i k e A r d u i n o , Sanguinololu, etc. (small cheap computer boards), all drawings are downloadable

• some printers can (partially) replicate themselves, because are made with printed parts

Makerbot Replicator

• Third generation printer (the first two were the Cupcake and the Thing-o-Matic)

• Single or Dual head (can print in two colors, or two plastic types)

RepRap: Prusa/Mendel/Darwin/etc...

• Many variations on the theme

• Mostly designed (and marketed) by members of the hacker community in US and Europe

• Everything is open, you can buy or build/modify them

Not only from U.S.: the Ultimaker

• Developed in the Netherlands by a student (as a byproduct of his MSc thesis)

• €1194 fully open source

• Also CB-printer produces a nice Prusa derivative in Poland (full aluminum frame)

• In Italy: the PowerWASP 3D-printer, made by the WASP Project (it becomes a CNC by simply adding a Dremel)

Printrbot

• There are two very portable models, battery powered.

The Cube

• First cheap commercial "not-for-hackers" plug'n'play printer

• For children, families, etc.

• Also MakerBot's Replicator 2 is going on this track (less "open", but for a much larger market)

The Cube ($1299)

Makerbot Replicator 2 ($2199)

And many more...

• Different solutions

• Different level of skills required to operate

• Different prices

• Different philosophies

• The market is growing and still searching an equilibrium...

Laser + liquid resin

• a new printer by Formlab: it uses a special liquid resin that costs 3x more than plastic, has better resolution and precision.

History of the Personal Computer(is it repeating all again?)

? ???

Pro only first personal(for hackers)

really personal(mass produced)

Any market for 3D printing? many think so

The long tail by Chris Anderson

N=1

Cloning objects

• Combining 3D scanners with 3D printers, it becomes possible (and affordable) to make copies (1:1 or scaled) of objects (even at a distance!)

This summer, the Metropolitan Museum of Art held an event to make 3D scans and prints of works from throughout the museum. Participants used digital cameras and Autodesk’s 123D Catch to generate the 3D models, and then printed

them using MakerBot Replicators.

Met3D

Making new objects

• 3D printing isn't just about copying objects, but also about creating new things, that are impossible (or expensive, or difficult) to make with other technologies. At home!

Thingiverse & C.• www.thingiverse.com (specifically for

3D printing)

• www.grabcad.com (complex models, made for photo-rendering, maybe just 5% are printable)

• People sharing a LOT of 3D modifiable object models

• (almost) all are free, without DRM

Cubify & C.

3D printing for humans it isn't just for fun...

3D printing for the Developing World ... there are already some ideas

The 3D4D Challenge:Relieving Poverty, Encouraging Innovation

•The Challenge launched on the 1st May 2012 .•In May and early June 2012, techfortrade ran innovation workshops in the UK, USA, India, Kenya, South Africa and Romania to stimulate ideas.•Over 60 projects were submitted from individuals and organisations in the Americas, Europe, Asia, and Africa.•A shortlist of seven finalists was selected from initial entries. The finalists received a $1,000 research budget in order to further develop the concept in advance of the final selection event.•The final was held in London on October 19th 2012, as part of the first 3d Print Show.•The winning project came from the University of Washington in Seattle. Washington Open Object Fabricators (WOOF) won The 3D4D Challenge and a prize of $100,000 to help towards implementing the project.•WOOF’s winning project will enable waste plastic to be used as filament for 3D printing machines, to create new products. The winning team, Bethany Weeks, Matthew Rogge and Brandon Bowman, planto work with US based NGO, Water for Humans (WFH),to address local issues in water and sanitation inOaxaca, Mexico.

http://www.3d4dchallenge.org

http://www.textually.org/3DPrinting/cat_3d_printing_for.html

One project described here caught my eye. Called Happy Feet, it was one of the contestants in The 3D 4D Challence which took place in London last October. The slogan was “Relieving Poverty Encouraging Innovation.”

Among the contestants were Roy Ombatti and Harris Nyali from University of Nairobi’s Fablab. Their project, Happy Feet, aims to solve the jigger menace in Kenya by using 3d printing to make customised shoes for people suffering from Jigger. Thus a right shoe can be made differently than a left, depending on the level of infestation.

Jiggers are tiny parasites that resemble fleas. They embed themselves in the feet, hands or other exposed body parts of animals, including humans. Serious i n f e s t a t i o n s m a y l e a d t o s e v e r e inflammation leading to loss of toenails, auto amputation of digits, and death may also occur. The risk of secondary infection, such as tetanus, is also high. Jiggers live in dusty conditions and other unhygienic environments, and are generally associated with poverty-stricken populations.

“The shoes would be manufactured from reused plastic and would also be recyclable once they are worn out. Apart from the potential help that this project could bring to people affected by the jigger infestation, it can also provide employment for people.”

3D printers for science? ... we are investigating

An article on Naturehttp://www.nature.com/news/science-in-three-dimensions-the-print-revolution-1.10939

UK just opened a new £6M research centre

• ...and they are looking for young physicists and engineers

Archeology in 3D

• Old bones made of plastic?

• Louise Leakey (a 3rd generation archeologist ;-) and her latest initiative: "AfricanFossils"

http://africanfossils.org

At the ICTP too!

• "Beeswax as Dental Filling on a Neolithic Human Tooth" Federico Bernardini, Claudio Tuniz et al., 2012 PLoS ONE 7(9): e44904.

First&International&Workshop&on&

"Low$cost(3D(Printing(for(Science,(Education(and(Sustainable(Development"&

May&6&4&8,&2013&!(Miramare!)!Trieste,!Italy)!

!&

& The& Science& Dissemination& Unit& (SDU)& of& the& Abdus& Salam& International& Centre& for&Theoretical& Physics& (ICTP)& will& organize& First& International& Workshop& on& "Low$cost( 3D(Printing(for(Science,(Education(and(Sustainable(Development",&to&be&held&at&the&ICTP,&Trieste,&Italy&from&May&6&to&8,&&2013.&

&&

&& &

& New,& low4cost,& three4dimensional& printing& technologies& are& providing& exciting&opportunities& for& research,& education& and& humanitarian& projects& for& the& developing& world.&Using&digital&models,&the&3D&printers&create&or&replicate&solid&objects&out&of&plastic.&&& The& purpose& of& this& workshop& is& to& discuss& and& create& awareness& on& the& new& 3D&printing& through&demonstrations&on&a&number&of&available&competing& technologies,&as&well&as&presentations&of&ongoing&research&into&new&applications.&&& Special& focus&will& be& given& to& the& applicability&of& 3D&printing& to&promote& appropriate&technology&for&sustainable&development,&scientific&research&and&education.&

&& &

PARTICIPATION:&&&& Attendance& is& open& to& young& scientists& and& engineers& from& all& countries& that& are&members& of& the& United& Nations,& UNESCO& or& IAEA.& & As& the&Workshop&will& be& conducted& in&English,&participants&should&have&an&adequate&working&knowledge&of&that&language.&&Although&the& main& purpose& of& the& Centre& is& to& help& research& workers& from& developing& countries,&through&a&programme&of&training&activities&within&a&framework&of&international&cooperation,&a&limited& number& of& students& and& post4doctoral& scientists& from& developed& countries& are& also&welcome&to&attend.&&& As&a&rule,&travel&and&subsistence&expenses&of&the&participants&should&be&borne&by&the&home&institution.&&Every&effort&should&be&made&by&candidates&to&secure&support&for&their&fare&(or& at& least& half4fare).& &However,& limited& funds& are& available& for& some&participants&who&are&nationals&of,&and&working&in,&a&developing&country,&and&who&are&not&more&than&45&years&old.&&Such&support&is&available&only&for&those&who&attend&the&entire&activity.&Registration(is(free$of$charge(for(all(attendees." (APPLICATION:!

The&"On4line&Application"&form&can&be&accessed&at&the:(ICTP(activity(website:"&http://agenda.ictp.it/smr.php?2547&

inclusive&of&a&step$by$step(instruction&guide."((

ACTIVITIY"SECRETARIAT&Ms."Lisa"Iannitti"(smr2547)"

the&Abdus&Salam&International&Centre&for&Theoretical&Physics&Strada&Costiera&11,&&34014&Trieste,&Italy&

phone:&&+39404042240227,&Fax:&&+39404042240558,&E4mail:&smr2547@ictp.it&

((((((

DIRECTORS!!!

E.(CANESSA((ICTP)SDU)!

!C.(FONDA((ICTP)SDU)!

!M.(ZENNARO((ICTP)SDU)!

!!(!!!!!!!!!

! ((

NEW(DEADLINE(!

February(28,(2013

&&&&

ICTP&Home&page:&http://www.ictp.it/&

&&

!November!2012!(updated!Janaury!2013)!

STAMPA LA TUA IDEA IN 3DConcorso rivolto agli studenti delle scuole secondarie superiori

delle Provincie di Gorizia e Trieste

Le 5 migliori idee proposte dagli studenti verranno riprodotte usando una delle nuove stampanti 3D a basso costo del Laboratorio di Stampa 3D dell’ICTP per la produzione di oggetti in plastica di piccole dimensioni (max. 20x20x20 cm).

Per informazioni sul concorso visita il sito: http://1mm.it/idea3d

Inaugurazione & Open House

ICTP 3D Printing LabThese days, 3D printing is being used to mock up far more complex

systems, says Arthur Olson, who founded the molecular graphics lab at the Scripps Research Institute in La Jolla, California, 30 years ago. These include molecular environments made up of thousands of inter-acting proteins, which would be onerous-to-impossible to make any other way. With 3D printers, Olson says, “anybody can make a custom model”. But not everybody does: many researchers lack easy access to a printer, aren’t aware of the option or can’t afford the printouts (which can cost $100 or more).

Yet Olson says that these models can bring important insights. When he printed out one protein for a colleague, they found a curvy ‘tunnel’ of empty space running right through it. The conduit couldn’t be seen clearly on the computer screen, but a puff of air blown into one side of the model emerged from the other. Determining the length of such tun-nels can help researchers to work out whether, and how, those channels transport molecules. Doing that on the computer would have required some new code; with a model, a bit of string did the trick.

Software that lets researchers twist and turn such structures on a computer screen is extremely useful, says Olson, but inadequate. Even the most advanced software will let two atoms occupy the same space. And tinkering with molecules inside a computer is a grind — it takes time for the computer to re-render an object after every turn, and interpreting the pictures requires mental effort. Fiddling with a physical model, on the other hand, is more like play. “I don’t have to think about it; I just do it,” says Olson.

Olson is now trying to meld the tactile advantages of 3D printing with computer power: he has tagged printed models with small paper labels that can be recognized by a webcam, to create an ‘augmented reality’ view. In this way, a user can play with a physical model, while at the same time using the computer to explore aspects such as the potential energy of a given molecular arrangement. Olson is also looking forward to using printers that can more easily swap between rigid and bendable materials, so as to better replicate molecular behaviour such as protein folding.

THE CELLULAR MATRIXPrinter ‘inks’ aren’t limited to plastic. Biologists have been experiment-ing with printing human cells — either individually or in multi-cell blobs — that fuse together naturally. These techniques have successfully produced blood vessels and beating heart tissue. The ultimate dream of printing out working organs is still a long way off — if it proves possible at all. But in the short term, researchers see potential for printing out 3D cell structures far more life-like than the typical flat ones that grow in a Petri dish.

For example, Organovo, a company based in San Diego, California, has developed a printer to build 3D tissue structures that could be used to test pharmaceuticals. The most advanced model it has created so far is for fibrosis: an excess of hard fibrous tissue and scarring that arises from interactions between an organ’s internal cells and its outer layer. The company’s next step will be to test drugs on this system. “It might be the case that 3D printing isn’t the only way to do this, but it’s a good way,” says Keith Murphy, a chemical engineer and chief executive of Organovo.

Other groups are using 3D printing of plastic or collagen to con-struct scaffolds on which cells can grow. Carl Simon, a biologist with the biomaterials group at the US National Institute of Standards and Technology in Gaithersburg, Maryland, says that the intricacies of scaffold shape can help to determine how cells grow, or how stem cells differentiate into different cell types. With 3D printing, researchers

have a very controlled way to play with different scaffold configurations to see which work best. One problem, however, is that most 3D printers can produce details on the scale of only tens to hundreds of micrometres, whereas cells sense

differences at the single-micrometre level. Top-quality printers can currently achieve 100-nanometre resolutions by using very short laser bursts to cure plastics, says Neil Hopkinson, an engineer who works with 3D printing at the University of Sheffield, UK, but this is “still very much in the lab”.

CUSTOM TOOLSIn the meantime, basic plastic 3D printers are starting to allow researchers to knock out customized tools. Leroy Cronin, a chemist at the University of Glasgow, UK, grabbed headlines this year with his invention of ‘reactionware’ — printed plastic vessels for small-scale chemistry (M. D. Symes et al. Nature Chem. 4, 349–354; 2012). Cronin replaced the ‘inks’ in a $2,000 commercially available printer with silicone-based shower sealant, a catalyst and reactants, so that entire reaction set-ups could be printed out. The point, he says, is to make customizable chemistry widely accessible. His paper showed how reactionware might be harnessed to produce new chemicals or to make tiny amounts of specific pharmaceuticals on demand. For now, other chemists see the idea as a clever gimmick, and are waiting to see what applications will follow.

Researchers in other fields have found a more immediate use for the technology. Philippe Baveye, an environmental engineer at Rensselaer Polytechnic Institute in Troy, New York, uses 3D printing to make custom parts for a permeameter — a device used to meas-ure the flow of water through soils. Although commercially available devices are fine for routine work, he has often had to design his

own for more precise research — a task that previously required many hours on a lathe. Printing, he says, is much easier.

Perhaps more importantly, Baveye can share his product just by pub-lishing the design file. “The idea of being able to reproduce experiments described in the literature is taking on a new meaning,” he says.

Others agree that the real power of 3D printing lies in its ability to put science into the hands of the many. Cronin wants to enable anyone — whether in the far corners of Africa or in outer space — to print their own tiny drug factory. Museums can already distribute exact copies of rare or delicate fossils as widely as they wish. And students can print out whatever molecule they’re trying to come to grips with. “Through 3D printing,’ says Olson, “the ability to make physical models has become democratized.” ■ SEE EDITORIAL P.6

Nicola Jones is a freelance reporter based near Vancouver, Canada.

Printouts of Neanderthal skulls from a child (left) and a neonate.

NATURE.COMTo see a 3D printer in action, go to:go.nature.com/egiddx

THE REAL POWER OF 3D PRINTING LIES IN ITS

ABILITY TO PUT SCIENCE INTO THE HANDS OF THE MANY.

M. P

ON

CE

DE

LEÓ

N/C

. ZO

LLIK

OFE

R/U

NIV

. ZU

RIC

H

5 J U L Y 2 0 1 2 | V O L 4 8 7 | N A T U R E | 2 3

FEATURE NEWS

© 2012 Macmillan Publishers Limited. All rights reserved

Durante il pomeriggio aperto al pubblico, i v is i tator i potranno vedere e toccare alcuni oggett i stampati e s c o p r i r e c o m e funzionano numerose stampanti 3D.

Il nuovo Laboratorio di Stampa 3D dell’ICTP vuole diventare un luogo aperto alla creatività, con lo scopo di mettere in luce queste nuove tecnologie di stampa tridimensionale e di presentare r icerche per lo sviluppo di nuove applicazioni .

Mercoledì 27 Febbraio 2013ICTP Galileo Guesthouse11:00 Inaugurazione13:00 - 17:00 Aperto al pubblico

Nuove tecnologie di stampa tridimensionale a basso costo,

che usano modelli digitaliper creare o riprodurre

oggetti solidi, stannoaprendo opportunità

innovative per la ricerca, l’educazione e per

progetti umanitari originali.

Print

outs

of N

eand

erth

al sk

ulls

from

a c

hild

(left)

and

a n

eona

te.

(ph.

M. P

ONC

E DE

LEÓ

N/C.

ZO

LLIK

OFE

R/UN

IV. Z

URIC

H )

Per favorire la conoscenza e creatività dei giovani studenti, la Science Dissemination Unit (SDU) del Centro Internazionale di Fisica Teorica (ICTP) di Trieste promuove un concorso aperto a tutte le scuole secondarie superiori delle Provincie di Gorizia e di Trieste. Potranno partecipare al concorso gli studenti che frequentano i Licei, Istituti Tecnici e Professionali, nonché coloro che frequentano corsi di Istruzione e Formazione Professionale Regionale.

mappa tattile per ipovedenti stampa di un modello di mano stampa con plastica flessibile ICTP, Laboratorio di Stampa 3D

HOW do I print an object? ...practical 3D-printing for beginners

#1 - Design a model

• The first step for creating a 3D-printed object is to make a digital model of it.

• There are many CAD programs (Computer-aided Design software), some are even free and open source.

• To learn how to use well a CAD program is not easy, it may require some days (or months) and a lot of patience and practice...

Program VS WebApp

• Sometimes, for a simple model, is easier and quicker to use one of the specialized websites that provide visual tools for an easy and immediate creation and/or modification of your 3D models (these are called webapps).

• Examples (more will follow later, with a short demo):

• TinkerCAD (now closing)

• 3Dtin

• ShapeSmith

• Cubify

Examples: free software for technical 3D modeling

• SketchUp (by Trimble, was: by Google)

• FreeCAD (open source, Win/Mac/Linux)

• Blender (open source, Win/Mac/Linux)

• Autodesk Inventor Fusion (Win/Mac)

• OpenSCAD (programming language)

• and many others...

DEMO time after this boring lecture! ;-)

Now: Fusion 360 (beta)

SketchUp: http://www.sketchup.com

Examples: free software for artistic 3D modeling

• Sculptris (Win, Mac; DEMO time later, by Gaya)

• Autodesk 123D Design (Mac, Win, iPad, web)

• and a few beautiful webapps (e.g. Nervous System)

Sculptris: http://pixologic.com/sculptris/

File format: STL (StereoLithography)

An ASCII STL file begins with the line:

solid name

where name is an optional string. The file continues with any number of triangles, each represented as follows:

facet normal ni nj nk

outer loopvertex v1x v1y v1zvertex v2x v2y v2zvertex v3x v3y v3zendloopendfacet

where each n or v is a floating point number in sign-mantissa 'e'-sign-exponent format, e.g., "-2.648000e-002". The file concludes with:

endsolid name

The structure of the format suggests that other possibilities exist (e.g., facets with more than one 'loop', or loops with more than three vertices) but in practice, all facets are simple triangles.

[source: Wikipedia]

Free iPad Apps for 3D modeling with a “touch”

• netfabb (STL viewer only)

• MeshLab (STL viewer only)

• other viewers (3Dskope, KiwiViewer, vueCAD)

• Autodesk: 123D Sculpt (“rounded”), 123D Design (“squared”)

• Autodesk 123D Catch (3D scanning with iPad/iPhone camera)

• Autodesk 123D Make (cardboard 3D models! ;-)

#2 - Check & repair

• The STL files that have been created by the modeling software may not be yet ready for printing, they should be checked for problems.

• Software for control and repair:

• netfabb Studio Basic

• MeshLab (conversion too)

• Software for visualization:

• Pleasant3D (Mac only)

#3 - Slice

• Here comes the fun...

• In order to print, the model (STL file) should be first converted into a set of instructions (a common one is called G-code) that tell to the printer how to move the printing head, when and how much plastic to extrude, etc.

• This is called slicing, and your model is now a pile of layers.

• This is the MOST CRITICAL part of the whole process, the final quality of the printed object is determined almost entirely by a correct choice of values for the many different slicing parameters.

So, the next lesson will be on: SLICING, SLICING, SLICING...

#4 - Prepare the printer

• calibrate (level) the platform (printing bed) and clean it

• pre-heat the printing head

• load the plastic filament into the extruder

• extrude some plastic, in order to fill the nozzle

• start the print ;-)

#5 - Wait until finished

• Printing time for a small object can be 10-20 minutes.

• For an object the size of an apple, can be up to 1 hour and more (it depends on resolution, infill, and printer speed).

• Bigger objects can take 10+ hours, complex ones even 20+ hours...

• May be dangerous to leave a 3Dprinter completely unattended when printing (T > 200ºC, melted plastic, electricity, moving parts, wooden frame...).

#6 - Finishing

• After the print, you may want to give a few minutes for the object to cool down (it will be easier to detach it from the bed).

• You may have to remove raft/support structures.

• If needed, the object surface can be smoothed by using sandpaper (it may ruin the finishing), a chemical solvent (i.e. Acetone for ABS), heat (hot air blower) or a coating paint.

A world of plastic don’t pollute, 3D-print!

Many types of plastics

• ABS (Acrylonitrile Butadiene Styrene), petroleum based plastic (used for the Lego™ bricks)

• PLA (Polylactic Acid or Polylactide), a biodegradable plastic made out of plant starch

• 618 Nylon (®Taulman)

• PVA (Polyvinyl Alcohol), water-soluble

• HIPS (High Impact Polystyrene), soluble in Limonene

• others: soft PLA, temperature-sensitive plastic, wood-based, conductive, etc...

Filament

• Filament comes in two standard diameters, 1.75 mm and 3.0 mm. The 3.0 mm filament is somehow an older standard and is slowly being upstaged by the 1.75 mm because it can be pushed slightly more easily, controlled a little better and sometimes leaves fewer tails hanging off the sides of your object.

• Cost: around 35$ (30€) per kg.

• 1g of printed object ~ 0.03€

Recycling plasticwww.perpetualplasticproject.com

• make 3D-printed objects from recycled plastic

What can we PRINT? (with our low-cost 3D printers)

Small is beautiful• Common low-cost 3D-printers can

print objects with dimensions of less than 20x20x20cm

• In some models isn’t very difficult to increase the vertical size. Horizontal limits are harder to break.

• It is still possible to build larger object by combining together multiple parts (with glue, screws or joints).

• Big printings take a LONG time!

• The final dimensions of the object may slightly differ from what is expected, because of thermal contraction of plastic. Make some tests!

Start with the right 3D model (STL)

• It is important to create watertight meshes in your design, so that it is clear to the 3D printer what is the “inside” (which needs to be made up of 3D print material) and what is the “outside”. In short, ‘watertight mesh’ means that there are no holes, cracks or missing features on the mesh.

• Another source of troubles is a mesh with flipped triangles. They should be reversed to the proper orientation before the slicing.

• Software repairing tools are available (netfabb, MeshLab).

Details that make the difference...

• Small details are difficult to print: the diameter of the nozzle is usually in the range 0.3–0.5 mm, the head/platform movement resolution is ~0.1 mm.

• A typical value for layer thickness is 0.2 mm (range: 0.05–0.5 mm).

1mm

0.2 mm layer thickness

Slicing software: art, science, and pain in the neck ;-)

Solution: do many tests, and compare the results...

Beware of overhangs!

• 3D printers generally handles overhangs up to 45 degrees well without special tricks.

• If possible, rotate the 3D model in order to minimize the parts with an overhang (before slicing).

• Point a fan at the part during the print, to cool the filament as soon as it comes out of the nozzle (before it has a chance to droop and ruin the print).

• Turn on support material in the slicing software. This is a hassle because the process uses more plastic, takes longer to print, and you have to clean off the support material with a knife afterwards.

Support me, please!

• FDM-based printers usually cannot produce stalactite-like structures as well as extreme overhangs, since they would be unsupported during the build. If these cannot be avoided, an extra thin support structure may be added into the object, which can be broken or cut away after the print process.

• Most slicing software can create automatically such support structure.

BEFORE AFTER

CLE

ANIN

G P

RO

CES

S

Raft and Skirt

• Objects can be built on top of a “raft” of disposable material (i.e. the same plastic of the print and the support) instead of directly on the build surface. The raft is larger than the part and so has more adhesion. It can also prevent warping.

raft

support• Sometime, when the print starts

the filament is barely dribbling out of the empty nozzle. To solve this problem, a little bit of extra plastic can be extruded around the object before starting the actual print. This is called skirt.

skirt

Printing bed (platform)

• The goal is to stick the object onto the platform. A few solutions are:

• bare glass (or mirror)

• bare plywood or aluminum

• PLA: glass/plywood/aluminum covered by a layer of blue tape

• ABS: same, covered by Kapton tape and heated (~100+ ºC)

• or use some (spray) glue... Note: a non-heated bed can’t print ABS

Filling the empty

• 3D printing is an additive process. That means you aren't paying for a machine to take material away, but to build material up. So the less material your design needs (e.g. the less volume), the lower the cost.

• For this reason, most of the objects are printed with the infill parameter set to a value in the range: 10% to 50%

• Robustness is obtained with the proper number of perimeters (shells), and bottom/top layers.

Good 3D-printing is difficult...

IDEAL LIKELY TO BE WORST CASE

Thank you for your patience! (Oh yes, 3D-printed chocolate! ;-)