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Issue: 66 - Jun 15, 2014
What Is 3D Printing All About?
By: Robert Malinowski, DVM, MA
Robert Malinowski, DVM, MA

Despite the explosive growth in the popularity of the term "3D printing" over the last year, there is still a great deal of mystery over how exactly this exciting new technology works and how it will impact your life.  Much like a laser printer creating a tangible paper version of an electronic (Microsoft Word) document, a 3D printer can create a physical version of an object that previously existed only in the computer.  However, unlike a two-dimensional printer that merely adds a thin layer of ink or toner to a sheet of paper, a 3D printer is capable of creating objects of varying shapes and sizes.  It's a bit like a replicator from an episode of Star Trek - The Next Generation.  Our current technology isn't quite advanced enough to build things atom by atom though…

So, how exactly does a 3D printer work?  Let's start with analyzing how an everyday two-dimensional ink jet printer works.  The printer creates your document (or image) by spraying very small amounts of ink at specific locations on a piece of paper.  After many sprays, perhaps using several different colors of ink, the output is completed and you are left to behold a wonderfully printed photo of your dog Sparky or that Haiku poem you felt inspired to write at 3:00am last night.  What once existed only in the computer is now a physical object that can be posted proudly on your refrigerator door or brought to work to elicit comical feedback from your colleagues.

3D printers take this same basic concept to the next level.  There are many different types of 3D printers currently on the market, but the vast majority of consumer-level units use plastic materials (ABS or PLA) to create models.  Rather than spraying ink, they work by laying down very thin layers of plastic, gradually building the model from the bottom up.  The raw material for the printer is a spool of plastic called filament that looks a lot like fishing line.  The 3D printer slowly feeds the material into a component called an extruder that melts it and forms it into a thin layer.  The extruder looks like a cross between the print head on an ink jet printer and a hot glue gun.  Slowly, the extruder deposits layers that are about one-tenth of a millimeter thick.  It takes a long time before the model begins to resemble anything familiar. 

Unlike laser or ink jet printers, which can keep printing pages until they run out of ink and/or paper, 3D printers can only print models of a limited size.  This size, called the build volume, varies between manufacturers.  MakerBot, one of the most popular brands, have several different sized printers depending on your needs.  The Replicator Mini is the least expensive model and prints objects up to 4" x 4" x 5".  The next step up is the Replicator, which can print objects up to 10" x 8" x 6".  Finally, the goliath Replicator Z18 has a massive build volume of 12" x 12" x 18".  While MakerBot is an extremely popular brand, there are dozens of other companies that offer great printers, including Stratasys and Cubify.

So, let's say you've gone out and purchased a shiny new 3D printer.  The first question that comes to mind will undoubtedly be, how do I find models to print?  Luckily, there are many options.  There are two main methods when it comes to modeling: use existing models, or create your own.  Let's start with the first option.  There are already several thriving communities online that focus on sharing and/or selling models.  One of the most popular free sites is called Thingiverse.  Think of this as a online swap meet for 3D files.  Rather than trying to re-create the wheel and design a perfect bird feeder, for example, check Thingiverse first to see if it's already been done.  Inside, you'll have access to the digital files, along with comments and pictures from people that have already printed out the object.  TurboSquid is another great site that focuses on selling 3D models.  Here, you’ll find models of everything from coffee cups to elephants.

Of course, another approach is to build your own model.  There are several software programs available that make it easy to build an object from scratch.  Think of them as 3D versions of Adobe Photoshop.  Some examples include Mesh Mixer, Mesh Lab, Google SketchUp, TinkerCAD and Autodesk 123D.

Getting back to a veterinary focus, you may want to produce a model that’s less artistic and more clinically relevant.  Using specialized software, it is now possible to reconstruct the patient from CT and MRI data.  So, you can process CT images of a femur and actually build a physical bone model that can be used for pre-surgical planning or client education.  Think of the possibilities for visualizing fractures or complex surgical procedures.    

3D printing is rapidly evolving.  While the technology was in its infancy just a few years ago, it has quickly advanced to produce easy to use printers at affordable prices.  The next few years will bring continued growth in this area, creating printers that can use many different types of materials with even bigger print volumes.  In time, it’ll be possible to print objects of all shapes and sizes in the comfort of your own home.  Warp drive?  They’re still working on that one.