3D Printing 101: Machines, Software, Models & Tips
3D printing is rapidly making its way into studios, offices, factories, hospitals, research labs, schools, homes, and restaurants all around the globe. And even outside of it: the International Space Station has been equipped with a 3D printer since 2014. A 3D printer can make you anything, anywhere, with models ready in no time. Read on to find out how this is the right moment to invest in one, and what it can mean to you.
In this 3D Printing 101 you will learn everything you need to know about the kind of machines available to the mainstream customer, the things you need in order to get your desktop factory running, plus available materials and software. At the end of this guide, we challenge you to take a leap forward and upgrade your 3D printing skills up to the level of complete mastery.
What is 3D Printing?
3D printing is an additive manufacturing (AM) technique. In other words, it constructs three-dimensional objects in a layer-by-layer fashion, adding each consecutive layer on top of the previous one, thereby fusing them together. You may know it from the Marvel films, where parts of exosuits regularly roll out of the printer.
Or if you are from a previous generation, you may know it from Jurassic Park III (2001) where Alan Grant’s assistant creates the resonating chamber of a velociraptor on a ‘rapid prototyper.’ Leeloo’s parents in The Fifth Element (1997) are essentially robotic 3D printing equipment as she also comes into this world layer-by-layer, as do the action figures in Small Soldiers (1998).
And if you are still older than that: you may remember a Superman comic from 1964 where the sky-cruising hero from Krypton fuses powder in a microwave-like appliance in order to forge himself a few busts of his friends. It is the earliest known mention of the technology.
A Brief History of 3D Printing
Many great things were born in the 1980s, including 3D printing. A Japanese inventor at the Nagoya Municipal Industrial Research Institute developed two methods for fabricating plastic objects with a photo-hardening resin. By consecutively depositing layers of resin, each subjected to UV-light while being masked with a pattern before moving on to the next layer, it turned out to be possible to selectively harden an area of a specific shape and create a three-dimensional object.
This is what grew out to become the Stereolithography (SLA) process that Chuck Hull of 3D Systems patented in 1984. His contributions were the STL file format and several software algorithms that are still used in digital slicers today.
At the same time, DARPA, the United States Defense Advanced Research Projects Agency, sponsored the University of Texas at Austin to develop an own proprietary printing process. Widely known as Selective Laser Sintering (SLS), it comprised a high-power laser that fuses particles of plastic, metal, ceramic, or glass, layer-by-layer into solid objects. The patent expired in 2014 which enabled Formlabs to launch its own benchtop SLS machine, the Fuse1.
Another corporation, Stratasys, was working on its own 3D printing technology to enter the market. Fused Deposition Modeling (FDM), where molten plastic gets extruded by a robotic nozzle head in order to form the object’s cross sections, was developed in 1988 and commercialized by 1992 for professional audiences.
Fused Filament Fabrication (FFF) is an alternative name for the process referring specifically to the use of filament strands as input material, rather than the powder cartridges that professional FDM machines use.
An alternative process was developed at MIT in 1993 and involved the deposition of a layer of powder on a platform bed that was then selectively connected to the next layer in a specific area by depositing an in-between layer of binder material with inkjet print heads. Their machine working with polymers, metals, and ceramics, ZCorp launched it under the name Binder Jetting that same year.
The aforementioned processes form the core of what is known as 3D printing today. However there are several alternative and derivative processes. PolyJet printing (PJM/MJM), for example, uses photo curable resins similar to SLA, but deposits them with jetting heads rather than deriving material from a reservoir like vat polymerization techniques do. This enables multimaterial printing, including full-color prints and objects with graded flexibility, i.e. precisely controlled transitions from solid to fully flexible.
Laminated Object Manufacturing (LOM) is similar to binder jetting but instead of powder binds together sheet materials such as paper, plastic, or metal. When using ultrasonic vibrations instead of binders for metal, the process is called Ultrasonic Additive Manufacturing (UAM). After binding, an extra step cuts the required shape out of the layer.
The main disadvantage of this is the difficulty, often impossibility, of removing rest material out of hollow cavities. But it results in strong, wood-like parts that can be produced in full-color by some printers.
Direct Metal Laser Sintering (DMLS) is similar to SLS except for the fact that it works with metal alloys. A similar process, Selective Laser Melting, fully melts the material, rendering it more suitable for pure metals such as copper, aluminum, steel, titanium, and tungsten. NASA has developed its own metal 3D printing process called Electron-Beam Freeform Fabrication (EBF3) that utilizes wire feedstock so as to rapidly create large parts in the vacuum of space.
Note: As advanced as modern techniques are, the original inception of 3D printing can be attributed to a Mr. Ross Housholder who, in 1979, invented a simple technique to inject a curable material into a matrix at selective spots. Unfortunately his system proved quite complex and was never commercialized.
3D Printing vs. the Rest
|wdt_ID||Metrics||CNC Machining||Mass Production||Manual Crafts||3D Printing|
|6||Cost Per Part||★★☆☆☆||★★★★★||★★☆☆☆||★★★☆☆|
|7||Materials||ABS, PMMA, PP, wood, stone, metals, carbon fiber, PCB||Polymers, silicone, glass, metals, composite blends||Metals, wood, glass, composites, polyester, fabrics, leather, silicone casting, ceramics||PS, PE, PP, PA, ABS, PMMA, PET, TPU, PLA, wood-like, carbon-filled, metal-filled|
|8||Suitable Batch Size||10-100||2,000 – 2,000,000||10-100||1-2,000|
Before you join the hype and buy a 3D printer just like over a million consumers have done before you, consider what your goals are, and if 3D printing is the best method for your productions. Here are some questions to ask yourself:
- What kind of items will I be creating, and of which size and complexity are they?
- Which materials will I require during different phases of the development process?
- How much chemical and noise pollution will I tolerate in my living/work space?
- Who will use my 3D prints?
- How many prints will I be creating? Is there a future possibility of mass manufacturing my items?
The unique advantages of 3D printing are its ability to manifest the most intricate geometries, rapidly creating prototypes that evolve towards a final design, and the possibility for one-off, custom-built items.
If you require a mechanically accurate prototype in a material that is not available for 3D printers, and with an immaculate surface finish, subtractive machining is the best choice.
Step to mass-manufacturing when you need more than 2,000 items. Under that amount, consider 3D printing. Vacuum forming is interesting above 1,000 items but restricts part geometry to fit into a one-directional mold with substantial draft angles and edge fillets. Rotational molding is interesting above 1,000 items as well.
Processes such as blow molding and injection molding can handle astronomic production quantities and are viable above 10,000 items. Depending on its quality, a steel mold can be good for half a million to several millions of production cycles. Given that an injection mold can cost as much as twenty 3D printers and manufacturers have a typical lead time of ninety days, setting up and running a small 3D printer farm can be worth the investment.
The last alternative is to craft your items manually. Where 3D printing can achieve unreal levels of geometrical complexity and in a way allows for true digital craftsmanship, sometimes it lacks in imbuing specific qualities that can only be done by hand, such as with musical instruments, art, or pottery. Also silicone casting and carbon fiber lay-up techniques are largely dependent on manual labor.
Do not underestimate the time it takes to run a 3D printer; traditional handicraft can be a realistic alternative. A decent workshop can be installed for the same price as a few 3D printers nowadays.
Benefits of an In-house 3D Printer
Purchase a 3D printer only if you regularly need objects that are otherwise hard to obtain or you see that it will be a hobby for years to come. The advantages of having a printer in-house is that you can have your model within a few hours, and you are in full control of how the item will be printed.
Also, some companies that can arrange 3D printing for you will reject some items if they are of a nature that is outside of their focus area, such as internal mechanical parts, batch production, politically sensitive or intimate items, or when they feel that the product will be of low quality — even if you disagree.
Especially if you intend your prints to be not just models but items for actual use, it is advisable to stay as close to the production process as possible since it will have a significant impact on the quality of your products. 3D printed products typically require anywhere between three and ten revisions for optimization, sometimes even more for designs with complex functionalities.
Say, you want to create a personalized item as a gift for a friend with his details engraved onto it. The text may not come out quite right in the print in terms of size and detail. Nothing beats having a 3D printer nearby in order to freely experiment with different fonts and slicer settings and achieve that ‘just right’ Goldilocks moment.
The same goes for model cars, trains, boats, or aircraft: with your own machine you will be able to achieve the most realistic look and push the capabilities of your printer without compromising quality too much.
Consider another example: you are an avid gamer and want to 3D print your character as you progress along the game’s journey. With your own 3D printer, you can adorn your hero with new weapons, gear, and outfits the same day you acquired them in-game.
Own Vs. Service?
The cons of having your own printer vs. using a printing service bureau such as Shapeways, i.Materialise, Sculpteo, Kraftwürx, ProtoLabs, or Forecast3D, are the limited selection of materials, lower quality compared to a laser sintered part, and the upfront investment costs for the printer, filaments and work hours needed to get the system running properly.
For a medium-sized part of 4 x 4 x 2 inches, the break-even point for SLS vs. FDM is reached after just 40 prints. Also, a service bureau typically uses SLS machines, which in a single print run can create hundreds of items. Printing larger quantities will take you weeks on a single desktop 3D printer, whereas a service bureau can deliver in six days.
It is also possible to outsource your 3D printing practices to peer-to-peer services such as Treatstock. These connect you to people all over the world who are happy to do the printing for you. They typically don’t charge much more than the value of the time you would otherwise have to put in, so the break-even point for hub services vs. FDM lies somewhere between 200 and 400 prints. The disadvantages are that the print may turn out differently than you expected, and the 4-5 business day lead time.
Compare desktop 3D printing to your inkjet printer at home, and a service agency to the professional print shop around the corner; for finished, presentation-ready products you will go to the shop, while in-between process work is best done on your own machine.
Want to learn more about 3d printing services?
(Read our service comparison guide)
Which 3D Printer Do I Buy?
There is a plethora of 3D printers (view our buying guide) currently on offer, each having their strength in terms of printing volume, available materials, multi-material printing, build quality, expandability, open-source systems, and level-of-detail among other factors. It is most important to first decide on your plans with the tool:
- How large will my parts be on average?
- What is the minimum acceptable level of detail?
- In which product categories will I be printing —home, toys, jewelry, dental, repair work, prototypes, footwear, fashion, industrial, automotive?
- How many parts will I be printing per year?
- What kind of materials will I require?
- Are there any special functional components that I will need – snap fits, threaded caps, hinges?
Some of the most well-known brands are:
The Netherlands-based trusted company that offers high-end printers. The price point is high but the quality is incredible. The new S5 model has a large build volume of 330 x 240 x 300 mm compared to the 197 x 215 x 300 mm of the UM3. It has the best dual extrusion system currently on the market, WiFi operability, and a camera for remote monitoring. For a more affordable model, choose the UM2+, a single Bowden-type extruder that delivers great quality PLA prints with a build volume of 223 x 223 x 205 mm or 305 mm height for the Extended version.
This Barcelona-based business develops an impressive 3D printer, the Sigma R19. It has two independent nozzle heads for simultaneously printing two materials, colors, or parts. It works with proprietary nozzles ranging in diameter from 0.3 mm for high detail to 1 mm for ultra-fast prints. A maximum hot end temperature of 280°C vs. 260°C of the Ultimaker makes it more suitable to print engineering-grade materials such as POM. The build volume: 210 x 297 x 210 mm.
American brand that builds all-metal 3D printers. These work with a Direct Drive extrusion system, meaning that filaments aren’t pushed through a tube but pulled directly through the nozzle. As a bonus, it has a high-temperature hot end with a maximum temperature of 290°C, which enables you to print with engineering-grade materials such as PEEK. Plus there is an optional enclosure for printing in ABS. The build volume of the Mini 2 is 160 x 160 x 180 mm; the larger TAZ Workhorse offers 280 x 280 x 285 mm of pure printing joy.
This aluminum build printer is the brainchild of Czech inventor Josef Prusa. It is an open-source system that comes as a kit and can be assembled over a weekend. With a generous build volume of 250 x 210 x 210 mm and direct-drive gear extrusion system, it is suitable for a wide variety of prints and materials. The machine is especially great for flexible materials such as FilaFlex and NinjaFlex, and can be modified for food printing as well. It works with universal E3D nozzles which are available in many sizes and for low prices.
The hardened steel ones will be your choice for printing composite materials. The latest MK3S model has a heated bed for printing high quality materials and can be equipped with the Multi-Material 2S add-on for printing up to five materials simultaneously. Another smart feature is the sensor system that detects and prevents layer shifting errors in the prints.
A Californian consumer electronics conglomerate that happens to make excellent 3D printers for beginners. For those starting a hobby, the Monoprice Select Mini v2 offers a robust device with single Bowden-style extruder, heated build plate, WiFi connectivity, and 120 mm cubed build volume.
A drawback is the low printing speed of 55 mm/s. For the same price under 200 dollars you can also buy the Mini Delta which almost triples that print speed. It has a build volume 110 mm in diameter and 120 mm in height.
NOTE: In case you’re wondering what a Delta-style printer is: whereas a regular 3D printer has three separate movable arms for the X, Y, and Z direction, a Delta printer has three arms that move on vertical axes in order to triangulate the print head to its target locations. By keeping the print head at a light weight, much higher speeds are attained while retaining quality.
One of the most praised Chinese 3D printing equipment manufacturers. Their entry-level Finder model has a build volume of 140 mm cubed and can handle flexible as well as solid materials. The Creator Pro is the most popular choice with a build volume of 148 x 227 x 150 mm, has a heated bed, metal closed-box design and dual color printing capabilities. The Dreamer model has a similar size build platform, but with some extra features: WiFi control and a full-color touch screen.
Another noteworthy Chinese brand. They offer well-built entry-level machines. The X-Maker comes with a price as attractive as its design, and is equipped with a single extruder, closed-box, and heated bed. It has a build volume of 170 x 150 x 160 mm. For larger-sized printing endeavors, the X-Plus has a volume of 270 x 200 x 200 mm and offers an additional extruder for advanced materials such as carbon fiber, polycarbonate, and nylon.
Opt for this Chinese brand if you are looking for dramatically larger print sizes. The Raptor model offers a whopping 400 x 400 x 500 mm of blank space to be filled up with your creations. It has a reliable aluminum frame and direct drive print head suitable for all kinds of filaments. And all that for well under a thousand dollars. The downsides are the lack of heated bed and enclosed box. Choose the Vivedino T-Rex 3.0 if you want an independent dual extruder system and you are willing to pay the extra price.
There is a class of hybrid machines that can be outfitted to function either as 3D printer, laser cutter/engraver, or CNC mill. This for example enables the creation of low-batch plastic injection molds. The Snapmaker 2.0 truly tops the charts for 3-in-1 devices and its three models, the A150, A250, and A350 offer build volumes of respectively 160 x 160 x 145 mm, 230 x 235 x 250 mm, and 320 x 330 x 350 mm. Print quality is amazing and it comes equipped with a heated bed. The downsides are that it fails to print flexible materials, is fairly noisy, print speed is quite low, and this being a Kickstarter initiative you may have to wait for several months until receiving it. If you need a 3D printer quickly, you can order the Snapmaker Original with the reduced 125 mm cubed build volume.
If you decide to go the stereolithography route, the Elegoo Mars is your best entry portal. It has a build volume of 120 x 68 x 155 mm and the quality is leagues beyond what any FDM printer is capable of producing. It will also do much thinner wall thicknesses down to 0.5 mm. The downside? Preparing print files requires some expertise, and you basically need a well-ventilated lab environment for it, since you will be working with liquid resins that are skin and respiratory irritant.
If you want to take SLA 3D printing to a higher level, look no further than Formlabs. This Massachussetts-based corporation was founded by three MIT Media Lab students, and develops professional-level SLA printers targeted to the mainstream customer. Their latest Form 3 model utilizes a Low Force Stereolithography (LFS) process and advanced sensors for improved accuracy and repeatability. This makes it suitable for high-precision parts such as for surgical, dental, and jewelry applications. It has a build volume of 145 x 145 x 185 mm. The Form 3L model even quintuples that to a staggering 335 x 300 x 200 mm.
Does it need to go into the basement or garage?
The short answer: well, probably.
Most materials exude harmful fumes and even though the levels do not cause immediate health hazards, you will not want to run the risk of harmful long-term exposure for you and your family members. When in doubt, check your material’s safety data sheet for instructions. ABS and PET(G) filaments are known to emit volatiles at levels dozens times higher than the biodegradable PLA filament.
Some black filaments contain harmful chromium components. Polycarbonate is known to contain Bisphenol-A (BPA) which may disrupt hormonal levels, potentially causing behavioral, cardiovascular or neural problems, even cancer.
SLA resins are industrial chemicals that are harmful to aquatic life as well as the human body. Your best environmental choice is to use neutral tones of PLA or, in case of SLA printing, the newest plant-based resins. Based on soy or linseed oil instead of industrial core components, these are less harmful but will still contain esters, an epoxy component, and photo-initiators to make the compound curable.
Then there’s the noise. An SLA printer typically is very silent, yet does produce the constant humming of the cooling fan. For FDM printers, add to that the semi-melodic continuous chirping symphony of four fully active stepper motors. So typically you will want to create a dedicated, well-ventilated space for 3D printing, and in case of SLA, protect your eyes, hands and clothes from coming into contact with the resins.
If you are determined to have one on your kitchen counter, opt for a silent one such as the Monoprice Select Mini 2. To reduce the sound to an absolute minimum, put it behind closed doors and surround it with sound-absorbing foam panels.
Can I print with special filaments?
Yes! Whereas five years ago ABS and PLA were the go-to materials, this is no longer the case as the market supply has exploded with all kinds of polymers. Here are our recommendations.
A blend of PLA and wood fiber, the resemblance to actual wood is uncanny. In slicers such as Cura, it is possible even to install a script that creates slight variations in printing temperature as the printer progresses upwards through the layers. This results in a banded effect. It can be printed like regular PLA except for the fact that filaments with fiber contents tend to accumulate inside the nozzle, causing clogs. So be prepared to do some nozzle cleanup, or prevent it all by using a larger 0.6 or 0.8 mm nozzle. There are filaments that look more akin to cork or bamboo as well.
Metal slivers are added to and can be printed like regular PLA, except that you will need a wear-resistant nozzle made out of anything but brass. There are alternative nozzles on the market made out of stainless steel, titanium, or copper for this application. There are many brands available, each with their own aesthetic quality. Check out metallic filaments as well; they add a little extra pizzazz to your prints, making them more suitable for end-use items.
Besides being fully recyclable, some brands of PET filaments have been FDA approved for food safety and medical grade applications. Its ductility also renders it suitable for flex hinges. Modified versions include PET-G and PET-T which have different flexibility and grip properties.
There is a class of advanced materials purposed for creating mechanically stronger parts. These include nylon, copolyester (CPE), POM, and PEEK. POM is great for wear-resistant objects such as gears, and resists weathering in outdoor applications. Nylon is a good overall choice but is highly hygroscopic, i.e. it can absorb a significant amount of moisture within days and therefore needs to be oven-dried for five hours at 60-70 degrees before use. Also note that for many of these materials you will require a high-temperature nozzle and heated bed, so check your printer specs for compatibility.
Finally, there are even stronger, carbon-filled filaments available. These do require some printing expertise in order to make them work well, and will wear out your nozzles fast.
Soon after PLA filaments hit the market, FlexPLA was introduced as the flexible alternative. It is similar in chemical makeup except for the addition of plasticizers for the extra bendability. With a 92-98 Shore A hardness it is only slightly flexible, but it does print well in most direct-drive extruders. It is trickier for Bowden extruders, but some, such as the Ultimaker 3 and Wanhao Duplicator 5S, will manage.
Other flexible materials belong to the class of thermoplastic elastomers (TPEs). Its urethane-based variant, TPU, is the least flexible. A popular but pricey TPU filament is Ninjaflex, which is tough and at 85A hardness also quite bendy. Filaflex is even softer at 82A, and then there’s Ultra-Soft Filaflex at 70 Shore A.
This is nearing the softness of silicone and is perfect for fashion and footwear projects. It comes only in the 2.85 mm diameter version, and is gnarly to print with; you will need a specific printer such as the Prusa i3, or modify your existing printer to work with dedicated extrusion systems such as the Recreus Extruder, E3D Titan Aero Extruder,or Wasp Extruder.
Polycaprolactone, or PCL, is a biodegradable and biocompatible polyester with a low melting point of 60°C. After printing, leave the object in hot water for a minute and it will be manually malleable. This makes it ideal for parts that require a specific fit to other parts, or to the human body in case of prosthetics/orthotics.
A critical material for owners of a dual-extrusion machine that require high quality print surfaces all around the model. When used as a support material printed by your second extruder, it can be dissolved in water during post-processing, leaving a perfectly clean print. The drawback is that it is harmful to the environment when disposed of.
There are wax-like filaments available, such as Polycast and MoldLay, that are useful for burnout processes such as lost-wax or investment casting. A gypsum or concrete mold is built around the print, which is then melted out, leaving the cavity for reproducing the object in metals. This material is quite soft at room temperature which also renders it perfect for sculptors who prefer to manually work sculptural details into a print.
Not to be neglected, ‘standard’ PLA is also a special material. With monomers derived from sugar cane, corn, or cassava, it is said to be biodegradable. However in fact, that’s hardly the case — it only degrades hydrolytically in specific environments. A PLA part will only degrade in a natural environment if you have a compost heap over 58°C and perfused with water. But there are alternatives.
What to think of filament made of solid carbon residue generated as a byproduct of pyrolysis, a waste disposal process that generates bio oil, biogas, and waste heat that can be used for residential heating. Or filament made of rest products of beer or coffee making processes.
Then there are bio filaments with substantial fills of hemp, algae, gypsum, or sandstone. There now is also an ecologically friendly alternative to dissolvable filament called HydroSupport. Another recycling solution comes in the form of the ReForm filament range which is made out of disposed prints.
Consider also glow-in-the-dark, multicolor/rainbow, thermochromic (color-changing), conductive, magnetic, glitter, transparent, and architectural filaments that look like brick, clay, concrete, stone, sand, or marble
What else do I need?
- Blue tape or paper tape. Or a PEI sheet for ultimate bed adhesion. In case of ABS: kapton tape and hairspray
- Spray adhesive for additional bed adhesion
- Scraper tool to remove prints from the bed
- Deburring tool to remove remaining material, ‘flanges,’ from the edges of the print
- Nozzle drills in case of clogs
- A pair of pointed-nose pliers, wire cutters, pincers, tweezers, tongs, PCB cutters, or anything else you can think of to pry off support material
- Sealable boxes or buckets for filament storage
- An oven in order to revive old, brittle, or moisture-laden filaments
- Ziploc bags and space for storing filament waste
- Sewing machine oil for lubricating the linear motion rods
- Magnalube green grease for lubricating the Z-leadscrew
- Acetone for smoothing out ABS prints
- A supply of spare parts might the printer suddenly fail
- Scraper tool to remove prints from the bed
- Measuring cup in mL
- PCB cutters and 600-grit sandpaper to remove support material remains
- A spare FEP film is a good idea
- Protective goggles
- Protective latex or nitrile gloves
- An overall suit or lab coat, ideally
- Well-ventilated space
- A funnel for pouring filament back into the bottle
- Paper filters to weed out contaminants
- Two suitable containers to fill with alcohol and soak your prints in
- A pair of tweezers to handle the prints without damaging fragile areas
- UV light box for post-curing prints, unless you live near the equator. Manicure devices will do if the frequency is around 405 nm.
- Ziploc bags and space for storing filament waste
- 95+% alcohol spray bottle and lots of paper towels for cleaning everything
3D Printing Process: How it Works
On a larger scale, 3D printing is part of a subset of processes known as Digital Manufacturing. As the 3D printer requires not much else besides input material and a digital 3D CAD (Computer-Aided Manufacturing) file, it does away with any needs for mold and/or tool making. This drastically improves development times and allows individuals and small companies to become producers in their own right.
It is revolutionizing the practices of independent entrepreneurialism, architecture, art, jewelry, toy making, cultural preservation, paleontology, forensics, fashion and product design, as well as the healthcare, dental, automotive, and aerospace industries.
The digital fabrication process typically starts with an idea in the form of a sketch, blueprint, or mock-up that the design team has created. A 3D modeler then converts it into a 3D design. Alternatively, ready-made designs can be downloaded from online repositories. You’ll need to explicitly search for 3D printable files on websites such as Thingiverse, CGTrader, MyMiniFactory, and Cults3D.
Browse to the end of the article for a list of recommended models for you to start 3D printing. Even then, many of these files will require some post-editing to make them work on your 3D printer. At times, 3D printing is not as plug-and-play as you may expect.
Another great source for print files is to invest in your own 3D scanner such as the Structure Sensor or the Sense 2. At the same price range as an entry-level 3D printer, these have become affordable to the average user. With the right software and a powerful computer it is possible to create 3D models from a set of photos as well — a practice called Photogrammetry. Then again, both 3D scanning and photogrammetry models are often full of imperfections and require above amateur-level skills in mesh optimization in order to make them work.
Before starting to work on your mesh, determine the file format that you need. STL is the most common for 3D printing but sometimes you will decide on a format that stores additional data such as textures. Here are some common file formats you will come across:
- STL is a format originally developed for stereolithography – hence the abbreviation. It is the most commonly accepted file format and only stores geometry data, giving rise to compact files.
- OBJ as first created by Wavefront is a simple format storing vertex information to represent a 3D mesh. Besides vertex positions, it also stores surface normals plus a UV-coordinate that can be mapped to an image-based texture saved separately from the mesh.
- 3DS is a less popular alternative to OBJ and used in conjunction with Autodesk 3D Studio Max, where it allows for the storage of entire scenes including textures, cameras, and lighting. Disadvantages are less compatibility with common software, inaccurate face normals, and a limit of 65,536 vertex and polygons per mesh.
- PLY (Polygon) is a more extensive format developed at Stanford to aid the storage of 3D scanning data. One of its benefits is the possibility to assign properties such as texture data separately for both sides of a face.
- AMF (Additive Manufacturing Format) is an alternative to STL for 3D printing. Being XML-based, it will store additional data such as orientation, scale, patterning multiple objects, non-planar edges, and graded materials.
- 3MF (3D Manufacturing Format) is similar to AMF but less standardized as it is created by a consortium of companies. Microsoft being one of them, it’s Windows’ native 3D file format.
- OFF (Object File Format) is a simple, hand-programmable, text-based format that next to geometry also stores per-vertex color data.
- Collada (COLLaborative Design Activity) is a versatile format well-suited for digital assets that was developed by Sony. This now widely supported format allows developers to store rendering data such as animations, level-of-detail, shaders, as well as diffuse, normal, and specularity maps.
- VRML (Virtual Reality Markup Language) is similar to Collada but scriptable and compatible with web browsers.
We recommend MeshMixer as your mesh editor. It truly is the Swiss army knife for editing STL files and not only does it automatically repair errors such as holes and intersections; it’s possible to resculpt entire sections, stylize the model, or add useful features to it. And the best aspect? It is entirely free. Meshlab, another free piece of software, is good at handling 3D scanner data and can import and export many file formats.
In case you need more advanced functionalities, check out what Autodesk Netfabb and Materialise Magics have to offer. At the end of the mesh editing step, always check if your model is manifold, i.e. every shell has one inside and one outside, is without any holes, and has all triangles connected.
TIP: Run a remeshing algorithm for every mesh file you prepare for printing; it optimizes triangle count saving you disk space in the long term, and can improve your model’s manifoldness.
The slicer is a piece of software that converts your 3D file into a machine-readable format. Sometimes this is a proprietary format as with the Anycubic Photon and Elegoo Mars SLA printers, but most of the time this entails the GCode format. It stores the literal instructions for the path your machine’s motors need to follow in terms of XYZ-coordinates, temperature, and printing speed. Most 3D printer brands come with their own slicer software which has its own user interface and print settings. Good settings create an aesthetically appealing, strong print; bad settings create issues such as bad surface quality, warping, weak areas on a print that takes many hours if not days.
Need to know slicing Settings
The most important settings are the various print speeds for the outer skin, inner skin, infill, and bottom layer of your print. The speed for the outer skin determines for a large part the surface quality; set it under 40mm/s for high quality, anywhere under 80mm/s still results in acceptable quality. The infill material is what fills up hollow sections inside your object, thereby adding strength to the part. You can set it to a quite high speed as long as strength is not compromised; this requires some experimentation for each material.
Set the infill percentage to 25% for regular parts, 40% for strong prints, or 15-20% as a minimum for faster prints. For the bottom layer, setting print speed to 25-30mm/s is a good rule-of-thumb, however some printers allow higher velocities. Then you can set the speed for the inner skin close to the maximum allowable value of the printer — it can literally cut the total print time in half.
The Flow Setting
Due to factors such as deviations in filament thickness, the feeder gear having too little grip on the filament, and friction in the Bowden tube, the extruder head or, occasionally, in the filament roll itself, the printer may be extruding either too little or too much. Flexible filaments, for example, often require a higher flow setting around 107%. Underextrusion results in very weak parts while overextrusion results in little globs of plastic spread all over the outer surface of the print, because the plastic gets ‘pushed’ outwards when pressure gets too high.
Both result in unacceptable print quality and each printer and material require some experimentation in order to get the settings right. A good way to figure out the best configuration is to print several versions of a small test object, changing one setting at a time. If you can change the settings through OctoPrint or on the printer itself, all the better, since you will only need one Gcode file. See the end of this guide for a list of suitable test objects.
The ‘Layer Height’ setting relates directly to the time required for completing a print. For prototypes that do not require a lot of visual detail, you can comfortably set it to 0.3 mm or even slightly above that. Maximum layer height depends on the size of your nozzle, for example a 0.8 mm nozzle can be set to 0.4 mm height without any problems, resulting in two to four times faster printing times.
The largest FDM printers have a 10 mm nozzle which can achieve a 3 mm layer height. A 0.25 mm layer height is still fairly coarse for a standard 0.4 mm nozzle, but at 0.2 mm there is reasonable detail. Higher detail is achieved at 0.15 mm, while the best setting for high quality prints is 0.1 mm. Going below that is not necessary as the difference is hardly visible, unless you’re looking through a magnifying glass. Never set the layer height to much more than half the nozzle size either; the newly deposited filament strand needs to fuse well with the underlying layer which requires enough of a contact surface to bond with.
Besides the myriad of print settings you can access with a slicer, another one of its main functionalities is adding support material. This prevents areas that are free-hanging in space to collapse during the print. When that happens, the nozzle will start to print in mid-air, often ruining the object.
Also, proper settings ensure quick support removal, preventing you needing to pry into your object for half an hour afterwards. We recommend using a zigzag-style support setting with a 15-17 % density and 50 degree minimum angle. This is easy to remove and uses little material. Using a lower angle is only recommended in case your model has large areas at an angle around 45 degrees, otherwise the difference in quality is hardly noticeable while it can save you a lot of support material and printing time.
An easy-to-remove support structure also ensures that it leaves little residue on the bottom surfaces of your print that would otherwise need to be cut off and sanded. If surface quality is of paramount importance for your purposes, consider investing in a dual extrusion printer. It allows you to print the supports separately in PVA filament, which can be removed afterwards by dissolving them in water.
SLS 3D printers have a better visual quality and do not require any supports since the powder bed supports itself. SLA printers have the highest surface quality of all processes but do require supports. In fact, supports for stereolithography parts need to be checked and modified manually in order to eliminate any free-hanging ‘islands.’
TIP: Print SLA parts under an angle so as to ease removal from the print bed, prevent excessive support structures, and eliminate large cross-sections that can cause the print to stick to the base of the resin vat due to suction forces.
Warping is a common problem in large prints. It happens when a part cools too quickly or unevenly. The corner areas of the print start to curling upwards and gradually start releasing the print from the bed. Your slicer can contribute to prevent warping issues, or even worse, prints coming off the bed entirely, by adding a so-called ‘Brim.’ This is a perimeter that your printer will lay down around the edges of your print on the first layer, in order to enlarge contact with the print bed. Twenty is a good number of brim lines for large objects, though in case that exceeds the bed size, using ten lines usually also prevents the aforementioned problems.
If warping still occurs, turn off the cooling fans and set the slicer to install a ‘Raft’ instead of a brim. This prints a thick grid in-between the build plate and model in order to distribute the heat more evenly. A closed-box type 3D printer plus heated bed will also be advantageous in preventing warping issues.
In addition to the brim, slicers print a ‘Skirt,’ often by default. This supposedly ensures proper material flow through the nozzle, a ‘clean’ filament after changing out materials, and proper bed alignment. The disadvantage is that a skirt is so thin that it is hard to remove from the print bed, sometimes leaving bits that stick to the first layer of your next print job.
It only results in more printing and handling time plus extra waste. Our tip: leave the skirt for what it is and either manually extrude a bit of material before every print, or add some lines of Gcode to the start of the slicer file to do that for you.
Starting the Print
This is where real things start to happen. Your virtual file gets transferred to the printer and out comes your creation. Some of the older printers such as the 3DRAG and Velleman K8200 require a USB cable to be connected during the print. The advantage is that you can readjust settings on-the-fly. Where most other printers use SD Card storage, some high-end consumer-level printers such as the Ultimaker 3 have a WiFi connection with live camera feed in order to remotely start, monitor, and control prints.
For many lower-end printers such as the older Ultimaker models, Anet, Creality, Geetech, Monoprice, Prusa, and Lulzbot, it is possible to set up a remote connection using OctoPrint.
To prevent warping issues, it is important that your print sticks sufficiently to the build platform. Unless it has a coarse surface such as the glass fiber platform of the Velleman K8200, you will need masking tape. Standard painter’s tape works well too for small prints that do not require the most adhesion. For larger prints, regular blue tape does the job, but we found that Wanhao’s paper tape takes the cake.
If you need even more stickiness, add a spray adhesive such as PrintaFix. This is especially critical for large prints with a significant portion of the material situated near the build platform, or for slender tall prints which the nozzle may gradually start to topple over when nearing the top layers.
The build quality of your printer will determine the amount of maintenance you will need to be doing. Materials that warp over time, such as wood and plastics, will develop tiny deviations over time, which require more routine checkups. This involves running the bed leveling procedure, tensioning springs and belts, and checking the wiring. A steel or aluminum enclosure is always superior.
With everything in order, you can now start printing. It is a good idea to stick with the printer for the first few layers of the print in order to ensure proper adhesion and filament flow. Never leave the printer unattended for too long since issues may develop during the course of the print.
TIP: When changing out filaments, occasionally do a ‘cold pull’ technique: let the nozzle cool down to 90°C, or around the glass transition temperature of your material, then gently tug on the filament and gradually increase your pulling force for a few seconds until the filament starts coming out. Then pull it out all the way. Because the filament is not in a completely liquid state, it will bring up any residue and dirt left inside the nozzle.
3D Modeling Software
There are many solutions for creating your own 3D models. Before selecting a Computer-Aided Design (CAD) environment, you will first need to make a choice as to the type of objects you intend to be making; will they mostly be sculptural objects, simple geometry, or complex surfaces (as in automotive design)?
Mesh editor MeshMixer offers the basic tools to start with a simple solid such as a cube or sphere, and sculpt it into anything you need. For a bit of a more dedicated sculpting environment, choose Sculptris. This is also free. It works exclusively with the OBJ file format so you will need MeshLab to convert your files to and from STL. Even more advanced is the paid-for sculpting platform ZBrush.
For a mesh-based modeling environment that, next to sculpting also offers advanced visual effects, UV mapping, animation, and a fantastic photorealistic renderer, choose Blender. After the sculpting process you will need to ensure that your model is watertight, hollow it out with a proper wall thickness, and add drain holes in case of SLS or SLA printing processes. Check the YouTube channel Maker’s Muse for worthy workflow advice.
If you want an altogether more advanced program, go for Fusion360. It offers many modeling features including dimensioning and basic surface operations, which are stored in a history tree. This means that you can always revert to a previous state of the model and alter the separate modeling features. Also, the program is geared towards 3D printing and offers several ingenious part optimization modules.
The most advanced parts require complex surfacing operations. If you want to be designing cars, and need them to be less boxy than the Tesla Cybertruck, you will need a program like Rhinoceros.
The price is sub-1,000 dollars and with that, you get a versatile modeling environment that with the right tutorials is surprisingly easy to learn and can make anything you desire, including the most complex of surface transitions such as A-pillar blends, multi-surface fillets, and flame surfacing. At its basis lies the NURBS system which is a mathematical way of describing complex curves. Curves are drawn by means of control points, and surfaces are typically swept, ‘lofted,’ through these curves.
Rhinoceros offers all the tools to convert your design into a 3D printable object and optimize the mesh before exporting. What’s more, the free Grasshopper plugin allows you to create scripts that generate complex textures onto your surfaces. With a mostly visually based user interface, you will master the basics soon, and the rest is very much learning by doing.
Your First 3D Prints
At first, you will be exploring the capabilities of your 3D printer. Your first object may not come out quite right. Therefore we recommend to initially print a round of test models in order to familiarize yourself with the various aspects of 3D printing. There are a few models available on Thingiverse that incorporate potential problem areas such as overhangs, bridges, and high-detail areas. Find them here:
- Thingiverse by 3DHubs (2013). Marvin – Key Chain. https://www.thingiverse.com/thing:215703
- Thingiverse by Majda107 (2017). All-In-One 3D Printer Test. https://www.thingiverse.com/thing:2656594
- Thingiverse by Thingster (2013). Massive Overhang Test. https://www.thingiverse.com/thing:40382
- Thingiverse by CreativeTools (2015). 3DBenchy – The Jolly 3D Printing Torture Test. https://www.thingiverse.com/thing:763622
Here is one specifically geared towards resin printers:
- Thingiverse by 3DSLA (2015). SLA Test Model. https://www.thingiverse.com/thing:1219068
Once these come out right, you are ready to create a few objects of your choice. I suggest you start with several different objects in different categories, such as a toy for your children (if you have any), something for your friend or spouse to wear, and something neat for yourself. This way you are promoting your mini-factory, you learn how everyone around you will react to your newly bought machine, and what you need to work on to improve.
Some of the best 3D printable toys are articulated figures that are available nowhere else. Or print your kid a fidget spinner unlike anything he’s ever seen before. For young children, the Flexi toys are very appealing. For older children, consider printing a scientific model of a cell, skeleton, planet, or molecule. For a bigger challenge, create a realistically painted 3D print of a complex multi-part figurine or movie prop.
- Cults3D by Louise Driggers: Articulated Figures, storage boxes and more https://cults3d.com/en/users/loubie/creations
- Cults3D by Adafruit: Hacks and toys. https://cults3d.com/en/users/Adafruit/creations
- Thingiverse by Amaochan. Movable Toys. https://www.thingiverse.com/amaochan/about
- Thingiverse by Blackwalt. Fidget Toys Collection. https://www.thingiverse.com/Blackwalt/collections/fidget-toys
- Thingiverse by CreativeTools (2015). Toy Dump Truck Trailer. https://www.thingiverse.com/thing:974758
- Thingiverse by Lucirez. Flexi Movable Toys Collection. https://www.thingiverse.com/lucirez/collections/flexi
- Thingiverse by Mag-net (2018). Howl’s Moving Castle. https://www.thingiverse.com/thing:2772256
- Thingiverse by VPSS. Biological Models. https://www.thingiverse.com/VPSS/collections/maquetes-e-afins
Here are some suggestions as a gift to a friend or spouse:
- MyMiniFactory by 3DCentral. Hanging Sloth Planter. https://www.myminifactory.com/object/3d-print-hanging-sloth-planter-22797
- MyMiniFactory by Be3D printers. Bow Tie. https://www.myminifactory.com/object/3d-print-bow-tie-01-flat-4613
- MyMiniFactory by berpixel. Brain Cap. https://www.myminifactory.com/object/3d-print-brain-cap-4536
- MyMiniFactory by Cemal Cetinkaya. Lepy Bracelet. https://www.myminifactory.com/object/3d-print-lepy-bracelet-5793
- MyMiniFactory by DidierKlein. Wave Vase. https://www.myminifactory.com/object/3d-print-wave-vase-12882
- MyMiniFactory by Evavooo. Crow decorative piece. https://www.myminifactory.com/object/3d-print-crow-support-free-5861
- MyMiniFactory byFranc Falco. Rubber Beach Sandal. https://www.myminifactory.com/object/3d-print-rubber-beach-sandal-uk-size-4-10041
- MyMiniFactory by gCreate. Bonsai Root Planter. https://www.myminifactory.com/object/3d-print-gcreate-bonsai-root-planter-15139
- MyMiniFactory by MakeAnything. Spin Vase. https://www.myminifactory.com/object/3d-print-spin-vase-38295
- MyMiniFactory by MDd. Dodeca Helical Vent Chandelier. https://www.myminifactory.com/object/3d-print-dodeca-helical-vent-chandelier-68066
- MyMiniFactory by Recreus3D. Recreus Sneakers II. https://www.myminifactory.com/object/3d-print-recreus-sneakers-ii-23527
- MyMiniFactory by sb. Tatted Lace Collar. https://www.myminifactory.com/object/3d-print-tatted-lace-collar-49942
- MyMiniFactory by Skeletonbolts. The Big Tooth 2.0. https://www.myminifactory.com/object/3d-print-the-big-tooth-2-0-5759
- MyMiniFactory by Womp. Classic Flat Shoe. https://www.myminifactory.com/object/3d-print-classic-flat-3137
- Thingiverse by Bcskillings. Home Items. https://www.thingiverse.com/bcskillings/collections/home
The highest difficulty in 3D printing lies in accurate biological, pre-surgical, and paleontological models. Besides, a 3D printed dinosaur fossil will be a great gift to yourself as a first reward for the successful conception of your 3D printing initiative.
As a bonus, we have gathered the best printable models:
- Cults3D by Arric. Deinonychus Skull. https://cults3d.com/en/3d-model/art/deinonychus-skull
- Cults3D by Arric. Dilophosaurus Skull. https://cults3d.com/en/3d-model/art/dilophosaurus-skull
- Cults3D by Arric. Spinosaurus Skull. https://cults3d.com/en/3d-model/art/spinosaurus-dinosaur-skull
- Cults3D by Inhuman Species. Oviraptor Skull. https://cults3d.com/en/3d-model/various/life-size-citipati-oviraptor-skull-and-cervical-vertebrae
- Cults3D by Think3DPrint. Eoraptor Skull. https://cults3d.com/en/3d-model/art/dinosaur-skull-eoraptor
- Cults3D by Think3DPrint. Tylosaurus Skull. https://cults3d.com/en/3d-model/various/mosasaur-skull-3d-print
- Cults3D by Think3DPrint. Psittacosaurus. https://cults3d.com/en/3d-model/art/psittacosaurus-2-dinosaur-model
- Gore, R.B. Carcharodontosaurus Skull (sculpt). https://www.artstation.com/rbgore/store/1KK8/carcharodontosaurus-skull
- MyMiniFactory by ScanTheWorld, Rogez Benoit, and Marchal Geoffrey (2017). Triceratops Skulls. https://www.myminifactory.com/object/3d-print-triceratops-skull-in-colorado-usa-6225 , https://www.myminifactory.com/object/3d-print-triceratops-horridus-43807 , https://www.myminifactory.com/object/3d-print-triceratops-34038
- MyMiniFactory by Kimberly Chapelle (2018). Massospondylus Skull (Sauropod) https://www.myminifactory.com/object/3d-print-massospondylus-skull-74140
- MyMiniFactory by National History Museum London (2014). Mammoth Cranium. https://www.myminifactory.com/object/3d-print-mammoth-cranium-at-the-natural-history-museum-london-5939
- MyMiniFactory by ScanTheWorld (2016). Hippopotamus Skull. https://www.myminifactory.com/object/3d-print-hippopotamus-skull-29110
- Nassif, J., and Witmer, L. (2016). Pachycephalosaurus Skull. https://www.morphosource.org/Detail/MediaDetail/Show/media_id/11590
- Sketchfab by Benoit Rogez. Nanotyrannus lancensis. https://sketchfab.com/3d-models/nanotyrannus-lancensis-young-t-rex-7b0967fa27674d959647868686b6717b
- Sketchfab by Olof Moleman (2015). Maiasaurus Skull. https://sketchfab.com/3d-models/young-maiasaura-skull-b8c1443629364d19a7c454efd3af47fa
- Sketchfab by Ramon Gonzalez Cabrera (2016). Camarasaurus Skull. https://sketchfab.com/3d-models/camarasaurs-skull-and-jaw-a2753346bb3b4148b32af57ca7e48631
- Sketchfab by Rankin Studio (2019). Teratophoneus Skull. https://sketchfab.com/3d-models/juvenile-teratophoneus-curriei-2d7c4e880c2e45289ebbade3ec479979
- Sketchfab by WitmerLab (2016). Euoplocephalus Skull. https://sketchfab.com/3d-models/euoplocephalus-armored-dinosaur-skull-137ae311d1574ffa8c10d130c901f05c
- Thingiverse by cyborg527 (2011). Dinosaur Skull (Deinonychus). https://www.thingiverse.com/thing:10447
- Thingiverse by gpvillamil (2011). Tarbosaurus Skull. https://www.thingiverse.com/thing:14173
- Thingiverse by Inhuman_Species (2017). Full Size Velociraptor Skull. https://www.thingiverse.com/thing:2736627
- Thingiverse by Inhuman_Species (2018). Pteranodon Skull. https://www.thingiverse.com/thing:2750535
- Thingiverse by lordlilapause (2017). Carnotaurus Skull. https://www.thingiverse.com/thing:2077208
- Thingiverse by Makerbot (2014). Saber-Toothed Cat Skull. https://www.thingiverse.com/thing:472463
- Thingiverse by Makerbot (2014). The T-Rex Skull. https://www.thingiverse.com/thing:308335
- Thingiverse by Pinkiguanas (2018). Allosaurus and Erlikosaurus Skull. https://www.thingiverse.com/thing:2967569
- YouMagine by The Printer Whisperer (2017). The Famous T-Rex Trix. https://www.youmagine.com/designs/trix-in-parts
If you want to search for your own models, here are several well-known repositories:
- CADNav – search for OBJ Models. http://www.cadnav.com/3d-models/sort-17.html
- Make sure to check out the Scan the World section! https://www.myminifactory.com/pages/explore
- Sketchfab (click ‘Download 3D Model’ underneath the visualization). https://sketchfab.com/3d-models
- Search Engine for printable 3D models. http://www.stlfinder.com/
- Search Engine for printable 3D models. https://www.yeggi.com
3D Printing: The Next Levels
In the end, it’s your choice what you use your 3D printer for. But we do have some final advice. Besides creating largely meaningless trinkets created to suit your personal hobbies, interests, and sentiments (which is great all in itself), designers and engineers develop things up to progressively more serious levels. The more thought, effort, and complexity get condensed into a design, the more valuable it becomes. Therefore we define five levels of 3D printing:
- Making. No thought is put in — the object simply comes to you as a simple idea, you create or download it, and hit the print button. There are legions of such objects on sites such as Thingiverse.
Example: a 3D printable flower vase with a cool modernistic pattern.
- Tinkering. You start to explore with various materials, different shapes, and remix 3D models into something new. This is exploratory and fun while serving some kind of purpose. When downloading objects, always check if the Creative Commons license included allows the creation of ‘derivatives.’
In our example: We want to work new floral and baroque elements into our modernist vase.
- Prototyping. Objects fulfill a definite functional use, and iteratively the creator finds out how to best design them.
Example: We want to add a pet drinking bowl to the design, but without the pet being able to easily access the plant, plant rests getting into the bowl, or the piece getting knocked over.
- Invention / Design. Your creation becomes part of a larger creative and commercial whole, with the goal of at one point bringing it to the real market for end-use by a specific customer segment. Now we have to think a little deeper and produce a higher quality product in order to make things work.
Example: We aim to develop a 3D printed vase that appeals to senior high-income museum-goers. They have to choose it over the vases made by the expert pottery legend in his uptown studio.
- Design Engineering. The creation process is part of a complex multi-dimensional parametrically-driven model. We need advanced simulations or tests in order to verify that our designs meet the criteria from a technological, user-friendliness, functional, aesthetic, and business point of view. This type of process is seen in large corporations developing complex systems such as Boeing, GM, SpaceX.
Example: Our 3D printed vases have to be optimized for integration into a spacecraft’s dashboard panel, and survive going to Mars as well as re-entry into Earth’s atmosphere. The panel is located two feet behind the heat shield which is also 3D printed.
We have discussed the history of 3D printing and its core technologies. We have explored in which cases it is superior to other manufacturing techniques, and why. Then we checked out several printers, tools, and materials. You now also know which software to use in order to design a model and optimize it for the 3D printer. And you know where to find existing model collections. So, let’s see how far we can get with this 3D printing thing!