3D Printing: What you need to know

Published Date
23 - Oct - 2011
| Last Updated
23 - Oct - 2011
3D Printing: What you need to know
3D printing adds a whole new dimension to printing—literally—and has the potential to revolutionize manufacturing, just for starters. We tell you what 3D printing is, what it can do, and how you can get involved with this exciting new technology.

3D printers: They're not your granddad's daisy wheel printer, or your mom's dot matrix. In fact, they bear little resemblance to today's document or photo printers, which can only print in boring old two dimensions. They can build objects from scratch—or rather, from a CAD or 3D scanner file—out of a variety of materials. They're gaining traction: You may have seen 3D printing demonstrated on the Colbert Report or other shows, and they filled a large pavilion at Maker Faire. Though still mostly found on shop floors or in design studios, and in the hands of hobbyists, they'll soon be coming to homes near you (if not your own), to be found on workbenches, in rec rooms, even in the kitchen. [RELATED_ARTICLE]

What is 3D printing?
3D printing is a manufacturing process in which material (plastic, metal, or other) is laid down, layer by layer, to form a 3-dimensional object. (It is deemed an additive process because the object is built up from scratch, as opposed to subtractive processes in which material is cut, drilled, milled, or machined off.) 3D printers employ a variety of techniques and materials, but they share the ability to turn digital files containing 3-dimensional data—whether created on a CAD (computer-aided design) program or from a 3D scanner—into physical objects.

Is 3D printing even printing?
Yes—although it's not printing as it's traditionally been defined. The relevant Webster's definitions for printing center around production of printed matter, publications or photographs; and producing by means of impression—the application of pressure. The first doesn't fit—unless the definition were expanded to include the fabrication of 3D objects, created from scratch rather than being printed on—and most 3D printing techniques don't involve impression.

From a technological perspective, though, 3D printing is an outgrowth of traditional printing, in which a layer of material is applied. Usually it's so thin that there is no noticeable height (though with solid ink printers, it is somewhat thicker). What 3D printing does is to greatly extend that height through the application of multiple layers, so it would make sense to expand the definition of printing to include the fabrication of 3-dimensional objects in this manner.

How does 3D printing work?
3D printers use a variety of technologies. Selective laser sintering (SLS) uses a high-powered laser to fuse particles of plastic, metal, ceramic, or glass. At the end of the job, the remaining material is recycled. In fused deposition modeling (FDM), ABS plastic or another thermoplastic is melted and deposited through a heated extrusion nozzle. The first 3D printers to come to market, made in the mid-1990s by Stratasys with help from IBM, used FDM, as do many personal printers like the ones from MakerBot and RepRap.

Multi-jet modeling is an inkjet-like 3D printing system that sprays a colored, glue-like binder onto successive layers of powder where the object is to be formed. This is among the fastest methods, and one of the few that supports color printing.

It's possible to modify a standard inkjet to print with materials other than ink. Enterprising do-it-yourselfers have built or modded print heads, generally piezoelectric heads, to work with various materials—in some cases printing out the print heads themselves on other 3D printers! Companies like MicroFab (www.microfab.com) sell 3D-capable print heads (as well as complete printing systems).

Another 3D printing technique exposes a liquid polymer to light from a digital light processing (DLP) projector, which hardens the polymer layer by layer until the object is built and the remaining liquid polymer is drained off. Electron beam melting (EBM) uses—you guessed it—an electron beam to melt metal powder, layer by layer. Titanium is often used with EBM to synthesize medical implants as well as aircraft parts.

Many techniques use a nozzle or other device to spray or extrude liquid or molten material onto a build platform on which the object is created. In many 3D printers the platform remains stationary while the nozzle moves, though sometimes the reverse is true. The object is created in accordance with the instructions in the CAD file that is the object's blueprint.

Depending on the technique, 3D printers can use a variety of materials, including but not limited to metals (stainless steel, solder, aluminum, and titanium among them); plastics and polymers; ceramics; plaster; glass; and even foodstuffs like cheese, icing, and chocolate.

Who invented 3D printing?
The first 3D printer was created by Charles W. (Chuck) Hull in the mid-1980s. It used a technique called stereolithography, in which a UV laser is shined into a vat of ultraviolet-sensitive photopolymer, tracing the object to be created on its surface. The polymer solidifies wherever the beam touches it, and the beam "prints" the object layer by layer per the instructions in the CAD/CAM (computer-aided design/computer-aided manufacturing) file it's working from. Hull founded a company called 3D Systems, which made stereolithography machines. Stereolithography is an expensive commercial technique, with machines usually costing $100,000 or more. Today 3D Systems sells 3D printers that use a variety of technologies and range from entry-level kits to advanced commercial systems, as well as providing on-demand parts services, mostly to business users.

What are the benefits of 3D printing?
3D printing gives designers the ability to quickly turn concepts into 3D models or prototypes (a.k.a., rapid prototyping), and allows for rapid design changes. It allows manufacturers to produce products on demand rather than in large runs, improving inventory management and reducing warehouse space. People in remote locations can fabricate objects that would otherwise be inaccessible to them. 3D printing can save money and material over subtractive manufacturing techniques in which material is cut, drilled, or shaved off, as very little raw material is wasted. And it promises to change the nature of manufacturing, eventually letting consumers download files for printing 3D objects—including, for example, electronics devices—in their own homes.

What can 3D printers make?
Designers use 3D printers to quickly create product models and prototypes from CAD drawings, but they're increasingly being used to make final products as well. Among the items made with 3D printers are shoe designs, furniture, wax castings for making jewelry, tools, tripods, gift and novelty items, and toys. The automotive and aviation industries use 3D printers to make parts. Artists can create sculptures, and architects can fabricate models of their projects. Archaeologists can make a 3D scan of a fragile artifact and print out a copy of the object. Likewise, paleontologists could duplicate, say, a dinosaur skeleton for display.

Physicians can use 3D printing to make prosthetics, hearing aids, artificial teeth, and bone grafts, as well as replicate models of organs, tumors, and other internal bodily structures from CT scans in preparation for surgery. Also, 3D printers are being developed that can lay down layers of cells to create artificial organs (such as a kidney https://www.ted.com/talks/anthony_atala_printing_a_human_kidney.html) and blood vessels (https://www.bbc.co.uk/news/technology-14946808) are already in the R&D phase. 3D printing can be used in forensics, for example to replicate a bullet lodged inside a victim (human or otherwise): https://www.youtube.com/watch?v=NKhpa5Nt6Ck

Printed electronics is a set of printing methods that enable electronic devices or circuitry to be printed on flexible material such as labels, fabrics, and cardboard, by application of electronic or optical inks. It provides very low-cost fabrication of low-performance devices. Printed electronics is beginning to be combined with 3D printing, allowing for the printing of layered circuitry or devices. A natural outgrowth of this potent combo is that someday you may be able to print out a future generation of gadgets from 3D plans rather than buying them.

Certain 3D printers can even be used in food preparation, to apply items in liquid or paste form such as cheese, icing, and chocolate. The French Culinary Institute has been using a Fab@Home (www.fabathome.org) open-source 3D printer developed at Cornell University to prepare artistic delicacies, and MIT has created a 3D food printer called the Cornucopia.

3D food printers could conceivably even match the Star Trek replicators, found in starship mess halls throughout the galaxy: These fictional food printers can fabricate most any food item on demand. If 3D printing lets doctors someday print a heart or kidney with internal structure, printing a steak or other foods should be a snap—though probably not cost-effective. (Maybe that's just as well, as few Earthlings could stomach a wriggling plate of gagh. https://en.memory-alpha.org/wiki/Gagh) At any rate, we're likely to see a far greater range of food products made by 3D printers at all levels of the "food chain": food manufacturers, restaurants, and home kitchens. 

What are 3D printing services?
You don't have to own a 3D printer to benefit from one. Many 3D printing services, such as Shapeways (https://www.shapeways.com) and Sculpteo (https://www.sculpteo.com/en/), print gift and other small items on order on their own 3D printers, then ship them to the customer. Customers can either submit their own CAD files or select items, most of them designed by other users of the service, from an online catalogue.

Can I get a 3D printer?
HP, in partnership with Stratasys, has introduced color and monochrome Designjet 3D printers, but they're only available in Europe and are priced beyond the reach of consumers (approximately $17,500). Fortunately, the past couple of years have seen the appearance of several relatively inexpensive 3D printers. They have largely come out of the so-called maker movement, which celebrates DIY and homebrew projects.

RepRap (https://reprap.org/wiki/Main_Page) is an open-source 3D printer that prints plastic objects—it even has the ability to replicate itself by printing most of the parts (under the instructions of its owner, we trust). Companies like Buildatron (https://buildatron.com) offer their own RepRap variants in kit form or fully assembled. An outgrowth of RepRap is MakerBot Industries (www.makerbot.com), which sells its (non-self-replicating) Thing-O-Matic 3D printer as a kit for $1,299 and the completed product for $2,500. A Dutch startup, Ultimaking Ltd. (https://shop.ultimaker.com/en), has launched the Ultimaker, a 3D printer kit (~$1,700) that it claims is much faster than MakerBot and can print larger objects, as it employs a moving printhead and a fixed build platform, rather than the other way around. The Up! 3D printer (https://pp3dp.com) comes pre-assembled (requiring about 15 minutes of setup), and can be had for less than $3,000. Along with a range of commercial systems, 3D printing pioneer 3D Systems also sells personal 3D printers such as the Botmill Glider (https://botmill.com/index.php/glider.html) ($1,395).

What software do I need to create files for 3D printing?
Nearly all 3D printers accept files in STL format. (STL stands for stereolithography; the format was devised by Chuck Hull, 3D printing's inventor.) These can be produced by most any CAD software, from expensive commercial packages like AutoCAD to free or open-source products such as Google SketchUp and Blender. Many 3D printer manufacturers include their own CAD software, which optimizes designing for 3D printing, with each printer they sell.

What does the future hold for 3D printing?
Within a decade, 3D printers will become commonplace in houses—to be found on workbenches, in studios, home offices, even in the kitchen. You may not find them in every household, but they'll become indispensible to those people who do have them. Items made with 3D printers have, for the most part, had solid, homogenous interiors, but we're likely to see more complex creations combining multiple materials down the line, including printable electronics. With today's 3D printers, if you lose your TV remote's battery cover you can print a replacement battery cover. With tomorrow's, if you lose your remote, you'll be able to print a new remote.

3D printing will gain a foothold in outer space. NASA is already experimenting with 3D printers, and Made in Space, a startup developing manufacturing solutions in outer space, has tested 3D printers in zero-gravity airplane flights. Made in Space's CEO Aaron Kemmer has described possible applications for 3D printing ranging from making on-demand parts for human missions to constructing large habitats optimized for space. Astronauts can't take a swing by Home Depot if they need to replace a valve or widget, but a 3D printer could fabricate one as needed.

Likewise, we'll see 3D printers in Antarctic bases and other remote locations, where folks can't wait 6 months for the next re-supply to replace essential parts or tools.

Medical applications of 3D printing don't stop with prosthetics, hearing aids, and dental crowns. (See "What Can 3D Printers Make?" above for a preview of what's in the works.) Replacement parts needn't be restricted to the mechanical.

3D printing is still in its infancy, and we're seeing an explosion in the variety and uses of these devices, largely spearheaded by startups and DIYers, with some big companies like HP starting to get involved. It's similar to where personal computing was in the late 1970s. Though it's easy enough to see some of the areas the fledgling field of 3D printing will branch into, others are beyond our ability to predict, just as no one around 1980 could have imagined much of what the personal computer would turn into. I'm not suggesting that the 3D printer will have the same impact as the PC, but it does have the potential to revolutionize manufacturing as well as bringing manufacturing into the hands of consumers. One thing's for sure, though: 3D printing is here to stay. 


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Source: 3D Printing: What You Need to Know

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