By now you’ve probably heard of how desktop 3D printers are revolutionizing the way we work, develop, and prototype product ideas. If you’ve never seen one in action though, you might be asking yourself, “How do 3D printers work?” In this article we'll discuss how they work, discuss a couple types of printers, and explore some things you can do with 3D printing, whether you own a printer not.

How Do 3D Printers Work?

Most consumer grade 3D printers work by building a base layer of plastic and adding to the base, layer upon layer to build the model. Just like an ink printer uses an X, Y coordinate system to deposit ink onto a page and form an image, a 3D printer uses an X, Y coordinate system to deposit plastic onto a platform. What makes it “3D” is that once the first layer of plastic is deposited to the X, Y coordinates, the printer starts a new layer on top of the first layer, incorporating the Z-axis. In order for the model to emerge in the form it was intended, each layer must be in the right place relative to the other layers.

The process starts with a spool of plastic. Usually the type of plastic used is ABS (Acrylonitrile Butadiene Styrene), or PLA (Polylactic Acid). ABS is the type of plastic used to make Lego blocks, and PLA is a biodegradable plastic made from renewable resources, and is often used in temporary medical implants because of its biodegradability. The plastic that comes off the spool is called filament. There are many other types of plastic used in 3D printing, but these two are the most common for consumer grade printers.

ABS and PLA Filament

The second part of the process is called extrusion. The extruder is a unit composed of several parts including a plunger, a motor with a wheel attached, an aluminum block, a heating element, and a nozzle. The filament is fed into the top of the extruder between the plunger and the wheel. The plunger pushes the filament against the wheel and when the motor turns, the wheel pulls the filament from the spool and forces it through the aluminum block.

Below is a picture of the top of an extruder; notice the clear filament being fed between the wheel and the plunger, and into the aluminum block.

Makerbot MK8 Extruder Top
Credit: Creative Tools:

The aluminum block supports the filament and ensures that it goes into the nozzle perfectly straight. The heating element heats the nozzle just enough that when the filament touches it, it softens. The filament is softened enough to allow it to squeeze through a very small hole in the nozzle, but not to the point that it completely melts. As it softens, it also becomes sticky so it can attach to either the build platform or the previous layer of plastic.

Below is a picture of the bottom of an extruder; the steel cylinder on the right is the heating element and the brass cone is the nozzle.

Makerbot MK8 Extruder Bottom
Credit: Creative Tools:

The final part of the process involves the build platform. The build platform is exactly what it sounds like, a platform that the model is built upon. The build platform area determines size in width and length that the model can be. Because the layers of plastic need to stay in the right place relative to each other and the extruder nozzle in order for the model to emerge as intended the first layer needs to stick to the build platform. If it didn’t stick to the platform the model would move around as the print progressed and it would end up as a big ball of tangled plastic. To help the base layer stick to the build platform, the platform is also heated in some types of printers.

MakerBot Replicator 2 Desktop 3D Printer
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(price as of Apr 28, 2014)

Another type of 3D printing is called “stereolithography.” Stereolithography uses a liquid plastic resin instead of a spool of filament. The way the printer turns that liquid into a modeled object is to shoot it with a laser, which hardens the plastic one layer at a time. The laser used in stereolithography allows the process to create much more detailed models than with the filament method.

At the time this article is being written, a company named Formlabs is conducting a crowdfunding campaign to produce a consumer grade stereolithography 3D printer. Watch their video to see it in action.

How 3D Printing Can Work For You

Make Things For Fun

Many 3D printer owners make things just for their own enjoyment. Some make toysor scale models of things. Some make jewelry or other wearable objects. Many people make a hobby out of making things that are a challenge to design and build: things with moving parts such as a chain with separate links, an action figure with movable limbs, or a globe made with multiple colors of plastic. An interesting website dedicated to all things 3D printing is At, users post all sorts of 3D printing designs, pictures, and topics. If you’re interested in 3D printing, or even if you want to see some amazing contraptions conceived by creative minds, it’s worth a look.

Make Parts For Things Around the House

How many times have you needed one little part to something that might have broken, and you don’t want to buy a whole new product or wait to get a replacement part? Having a 3D printer comes in handy when you just need to replace or repair something small. You can make a replacement cord lock for the strings on your sweatshirt if you lose one. You can make a replacement key for your keyboard to replace a broken one.

Prototype Your Product Ideas

The ability to prototype ideas quickly and cheaply is what makes 3D printers really shine. The costs to prototype products are high, usually require several iterations of the prototype, and take a long time to get those iterations into your hands if the prototyping is outsourced. Having a prototyping machine, literally on your desk, may allow you to produce and test several iterations of a prototype in one day and for mere pennies per print. If you have aspirations of making your product ideas a reality, a 3D printer may be well worth the investment.

Outsource 3D Printing

If you’re not sure whether you’re ready to buy a 3D printer, but you want to have some things printed, you’re in luck. There are many companies that now provide 3D printing services. The benefits of using these services to get your feet wet are that they produce high quality printed models from your designs, they often have a wide variety of materials to choose from, and they make it very easy to get your model made. You just upload your design files to their website, select a few options, pay, and they take care of the rest.,, and even are examples of companies that provide 3D printing services. Another option is to check for local 3D printer owners in your area that offer to print your models for a fee.

So now you know how 3D printers work, the different types of printers, what you can do with 3D printing, and even how to outsource your print jobs. Take this information and go check out the cool new desktop manufacturing revolution for yourself. Get your feet wet by using a 3D printing service, or jump right in and get your own printer and make a creative gift, or invent the world’s next cool gadget.