What is 3D Printing?

3D printing or additive manufacturing (AM) is a process of making a three-

dimensional solid object of virtually any shape from a digital model. 3D printing is achieved

using an additive process, where successive layers of material are laid down in different

shapes. 3D printing is thus distinct from traditional machining techniques, which rely on the

removal of material by methods such as cutting or drilling (subtractive processes).

3D printer is a limited type of industrial robot that is capable of carrying out an

additive process under computer control.

It can be used for making nonsensical little models like the over-printed Yoda, yet it

can also print manufacturing prototypes, end user products, quasi-legal guns, aircraft engine

parts and even human organs using a person’s own cells.

Fantastical? Yes. True? Yes. Here now? Yes.

We live in an age that is witness to what many are calling the Third Industrial

Revolution. 3D printing, more professionally called additive manufacturing, moves us away

from the Henry Ford era mass production line, and will bring us to a new reality of

customizable, one-off production.

Need a part for your washing machine? As it is now, you’d order from your repairman

who gets it from a distributor, who got it shipped from China, where they mass-produced

thousands of them at once, probably injection-molded from a very expensive mold. In the

future, the beginning of which is already here now, you will simply 3D print the part right in

your home, from a CAD file you downloaded. If you don’t have the right printer, just print it

at your local fab.

3D printers use a variety of very different types of additive manufacturing

technologies, but they all share one core thing in common: they create a three dimensional

object by building it layer by successive layer, until the entire object is complete. It’s much

like printing in two dimensions on a sheet of paper, but with an added third dimension: UP.

The Z-axis.

Each of these printed layers is a thinly-sliced, horizontal cross-section of the eventual

object. Imagine a multi-layer cake, with the baker laying down each layer one at a time until

the entire cake is formed. 3D printing is somewhat similar, but just a bit more precise than 3D

baking.

Stick with us and we’ll go through the various types of additive manufacturing. From

FDM printing, where a material is melted and extruded in layers, one upon the other, to SLS

printing, where a bed of powder material such as nylon or titanium is “sintered” (hardened)

layer upon thin layer within it until a model is pulled out of it. It’s a fascinating and quickly

advancing world that will change our lives as we know it.

It Begins with a Digital File

In the 2D world, a sheet of printed paper output from a printer was “designed” on the

computer in a program such as Microsoft Word. The file — the Word document — contains

the instructions that tell the printer what to do.

In the 3D world, a 3D printer also needs to have instructions for what to print. It needs

a file as well. The file — a Computer Aided Design (CAD) file — is created with the use of a

3D modeling program, either from scratch or beginning with a 3D model created by a 3D

scanner. Either way, the program creates a file that is sent to the 3D printer. Along the way,

software slices the design into hundreds, or more likely thousands, of horizontal layers. These

layers will be printed one atop the other until the 3D object is done.

Is it 3D Printing or Additive Manufacturing?

Someday soon enough in the future, people will look back and view our current

manufacturing processes as we today view something such as blacksmithing. What’s

interesting about that last sentence is that much of today’s manufacturing processes are

actually very similar to blacksmithing. Both are what’s called “subtractive manufacturing.”

Subtractive manufacturing relies upon the removal of material to create something.

The blacksmith hammered away at heated metal to create a product. Today, a CNC machine

cuts and drills and otherwise removes material from a larger initial block of material to create

a product. It’s inefficient and wasteful. Other manufacturing techniques abound but they all

essentially whittle down raw material into a product.

Additive manufacturing creates something by adding material to the object. Some

here, some there, and no where it’s not needed. No waste. Very efficient.

Commercial 3D printers

While most people have yet to even hear the term 3D printing, the process has been in

use for decades. Manufacturers have long used the printers in the design process to create

prototypes for traditional manufacturing. But until the last few years, the equipment has been

expensive and slow.

Now, fast 3D printers can be had for tens of thousands of dollars, and end up saving

the companies many times that amount in the prototyping process. For example, Nike uses

3D printers to create multi-colored prototypes of shoes. They used to spend thousands of

dollars on a prototype and wait weeks for it. Now, the cost is only in the hundreds of dollars,

and changes can be made instantly on the computer and the prototype reprinted on the same

day.

Some companies are using 3D printers for short run or custom manufacturing, where

the printed objects are not prototypes, but the actual end user product. As the speeds of 3D

printing go up and the prices come down, look for more and more of this. And expect more

availability of personally customized products.

Personal 3D Printers

There is a whole other world of 3D printers: personal and DIY hobbyist models. And

they are getting cheap, with prices typically in the range of $300 – $2,000.

The RepRap open source project really ignited this hobbyist market in the same way

the Apple I microcomputer ignited the hobbyist desktop computer market in the late 1970s.

For about a thousand dollars, people have been able to buy the RepRap kit and put together

their own personal 3D printer, complete with any customizations they were capable of

making. And what’s more, these printers print most of the parts for more printers. RepRap is

short for replicating rapid prototyper, so complete self-replication, including electronic circuit

boards, is the goal.

The interest in RepRap spawned scores of other low-cost 3D printers, both DIY and

fully-assembled, and as the prices keep coming down, it puts 3D printers into more and more

and more hands.

But do you have to be an engineer or a 3D modeling expert to create 3D models on

your own 3D printer? No, not at all. While complex and expensive CAD software like

AutoCAD and Solidworks have a steep learning curve, there are a number of other programs,

many free, that are very easy to learn. The free version of Google SketchUp, for example, is

very popular for its ease of use; and the free Blender program is popular for its advanced

features.

Even if you don’t design your own 3D model, you can still print some very cool

pieces. There are model repositories such as Thingiverse, 3D Parts Database, and 3D

Warehouse that have model files you can download for free.

What do all these people print? It’s limitless. Some print things like jewelry, some

print replacement parts for appliances such as their dishwasher, some invent all sorts of

original things, some create art, and some make toys for their kids. With the many types of

metal, plastic, glass, and other materials available (even gold and silver), just about anything

can be printed.

The Future of 3D Printing

This is a disruptive technology of mammoth proportions, with effects on energy use,

waste, customization, product availability, art, medicine, construction, the sciences, and of

course manufacturing. It will change the world as we know it. Before you know it.