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  • Charlie Kocur

How Do 3D Printers Work? The Basic Parts of a 3D Printer

Even though 3D printers are getting more and more popular each day, there is still a lot of mystery in the general public about what 3D printers are and how they work. My goal today is to demystify these cool little machines and encourage those who might be intimidated by them to pick up their own 3D printer. Once you are familiar with what I consider the four basic parts of a 3D printer and what each of them do, you will realize how simple they actually are.

I consider the basic components of a 3D to be broken down in to four main pieces: First is the frame, which defines the overall shape and function of the 3D printer. Second, the control box acts as the “brains” of the 3D printer. Next, the 3D printer bed is the surface the printer creates the model on. Finally, there is the extruder which melts and deposits the plastic printing filament where it needs to go to create the 3D model. All of these parts work together to create a 3D print.

If you’re a complete 3D printing beginner who is just starting to research on which 3D printer to buy, or someone who wants to learn more about a printer they just purchased (or heck, even if you’re just curious about 3D printing in general), read-on to learn why this technology is much simpler than you think!


 

Why Learn the Parts of a 3D Printer?

A main reason it’s important to learn the basics of how a 3D printer works is because it can ease some of the intimidation that can come from spending a bunch of money on something you aren’t even sure you can use.

When I decided to purchase my first 3D printer I did many month’s worth of research before actually taking the plunge. I wasn’t just hesitating on which printer to purchase, but I was also going back and forth over whether or not I should even purchase a printer at all.

They seemed intimidating; they seemed like something that required a really high level of technical skill. In the end, I’m extremely glad I finally decided to go ahead with buying one.

It turned out I had nothing to be worried about. As I got to know my printer, I found out that they are actually simple little devices and just require a little patience. If I had known that from the beginning, I may not have waited as long or been nervous about picking one up.

In addition to removing some of the intimidation factor, knowing on a basic level how 3D printers function can help to make an informed purchasing decision if you are shopping for your first printer. There are many desktop 3D printers on the market with more being introduced on a regular basis, so being informed can help you stay on top of it all.

All of these printers differ in quality and features. By knowing how a printer functions you can decide which features will make a difference and will give you the best chance of a positive printing experience. Being educated about something you are going to spend hundreds of hard-earned dollars on is a worthwhile effort. It’s my hope that this article can set you on the right path and will put your mind at ease to make an informed choice when buying your first 3D printer.


The Main Components of a 3D Printer

Now onto the real meat of this article, the basic components that make-up a 3D printer. I briefly want to preface this section with the statement that this list is not inclusive of all parts of a 3D printer. This is just an overview of what I consider the major pieces that make up the machine. They are things that I found were most important to be aware of after I spent months of research before buying my own first 3D printer.

Basically, I am condensing what I learned from my research and several years of first-hand experience operating my own 3D printer in to this one master article to make it a good beginner reference. My goal is to get more people involved with the 3D printing hobby, and save you time (and possibly money!) when doing your own research.

With that out of the way, let’s get on to the components that come together to make a printer work.

 

Component 1: The Frame



The most defining visual feature of any 3D printer is the frame. The frame of a 3D printer is the overall structure and defines what the printer looks like, how large it can print, and even how the printer works in general.

There are several types of common frames for 3D printers and the design is often dependent of the type of printer it is. In this section we will cover two that I see most often for home-grade, FDM-style printers. I will also make brief mentions of other styles that you may see while looking for your printer but that don’t seem to be as popular.

Box Frame

The box frame is often tied to what I would call the “prosumer” level 3D printers. They are meant for home use, but are usually at the more expensive end. In short, a box frame is exactly how it sounds. They are a full rectangular-cube structure with all of the 3D printing happening inside.

They can be either covered in clear plastic to form a complete chamber, or just simply a frame without panels covering the holes.

A good example of a closed style is the Dremel series of printers, such as the Dremel Digilab 3D20. While you can look to something like the MakerBot Replicator+ as an example of a non-enclosed frame.

(Note: Purchases made through the below image and text links help support this site through Amazon affiliates.

Dremel Digilab 3D20 3D Printer, Idea Builder for Brand New Hobbyists and Tinkerers MakerBot Replicator+ Award Winning 3D Printer, with swappable Smart Extruder+

There are a few different ways that I’ve seen these printers function:

  1. The printer bed remains stationary, and all of the movement comes from a gantry system (a series or rails that guides the printer extruder across the bed in all directions; X, Y, and Z axis).

  2. The printer bed moves along the Z-axis (up and down), while the gantry system moves the head left to right and forward and back (X & Y axis).

  3. The printer bed moves either left to right or forward and back (X or Y axis) and the extruder moves along the Z axis, as well as the X or Y axis (whichever one wasn’t handled by the bed movement).

The main advantage of the box frame is two-fold:
  • Strong & Rigid: A full box frame is solid and reduces the amount of vibrations and shaking that a printer might experience as it operates. As long as the printer is on a solid surface, it should be pretty stable.

  • Temperature: many of these style of printers are surrounded by clear, plastic panels, making the entire printing structure enclosed. This enclosure maintains a steady temperature throughout the print, which can improve quality (and is even sometimes required) to print with certain materials, like ABS plastics.

Some disadvantages of this frame might be:
  • Large space needed: There is not much leeway with these style printers. Make sure you measure well because they potentially could take up some space! This said, you will want to avoid clutter around any 3D printer to reduce the risk of fire hazards, so this is something that should be planned for no matter which style printer you buy.

  • Pricey: Generally, these printers cost a bit more than the other style of frame I will cover in this article. Higher-end printers seem to have this style of frame more often, so be aware you may be spending a little more for this style. That said, along with that price increase generally comes good quality.

  • Annoying to Fix: Since the entire printer is within a closed frame, it might be difficult to access the area needed if there is a problem that needs fixing.

“H-Frame”

While you may see different terms for this one out there (because I had trouble tracking-down an official name and this is what I've always called it), this style of frame is probably the most commonly seen one in the world of budget-friendly 3D printing.

It’s very popular because of its low cost and simplicity. In fact, this style of printer is what I started on and still use today. They’re functional, easy to set up, and are so common that it will be easy to find help resources if something does need troubleshooting.

The images used in this article are of my personal printer and is a good example of this frame design. This frame simply looks like a squared-off arch or a square. This style of frame generally works by having the printer extruder move along the X axis (left to right) and Z axis (up and down); while the 3D printer bed moves along the Y axis (front to back).

Here are a few other notable printers of this design. These are more budget friendly which is a nice plus!

Official Creality Ender 3 Pro 3D Printer with Glass Plate Eryone Thinker S 3D Printer with Resume Print 300x300x400mm XVICO X3 Pro 3D Printers DIY Kit

The advantages to the H-Frame include:
  • Ease of Setup: They’re quick to set up (because they fold and pack nicely into a shipping box).

  • Ease of Troubleshooting: Since this style is so popular, you are likely to find some excellent resources for the model of printer that is being used.

  • Ease of Access: Having a very open design vs. a box frame means easier access to fix issues should they come up.

Disadvantages of H-Frame printers include:
  • Less-Rigid Frame: Unlike the Box Frame printers that are a sturdy cube, vibrations and wobbles may be more apparent during printing with an A-Frame printer. There is some easy customization (using 3D printer parts!) that can be made though to reduce this. Search for "Z-brace" on any 3D model repository and you'll find plenty of examples.

  • Be Careful of Cheap Printers: This is less a knock on the frame style, but more of a note on the price range that these style printers happen to fall in. Part of the reason these are popular is because they work well, the other reason is that they’re a lower cost. Because of this, make sure you do some research before purchase. As mentioned though, because these are so popular, you will have plenty of resources available for this.


The other two styles of printer you will see fairly commonly, but not as common as the Box or A-Frame are:

Delta Printers:

Delta printers are a completely different style of printer from what I am familiar with. They are really cool to see operate and I’d recommend looking up a video because it’s hard to explain.

Because they’re less common than the other style printers and function a bit differently, I’d recommend doing some serious research in these if you’re thinking of getting one as your first printer. There might be slightly fewer troubleshooting resources out there because they're not quite as common.

The major advantage of delta printers is that they’re often built for speed. Because of how the unique mechanism operates, the printer head can move quickly, meaning fairly fast prints can be done.

They also are generally pretty self-contained and have a small, but tall footprint. Meaning you can create some pretty tall prints but you may be limited when it comes to width.


“Frameless” Printers:

While I’m not positive this is the formal term for it, it’s the term I use to make sure I remember what these look like. In short, these printers don’t have an overall frame to them, but instead rely on a very simple structure of moving parts. Personally, I think this is best for smaller-scale and slower printing. Printing anything large or fast with a printer without an overall support structure could result in some vibrations that could reduce the quality of a print.

A good example of this style printer is the Snapmaker 3-in-1 3D Printer. This device is unique in that it can be a 3D printer, a CNC Cutter, and a Laser engraver. But what I want to point out most is the design. As you can see in the product image, this has no “outer” frame, but instead all of the parts rest on a base that moving parts rest on top of.

Snapmaker Original 3-in-1 3D Printer (3D Printing/CNC Carving/Laser Engraving),All Metal,Entry-Level Digital Tool,Easy to Use Software,Upgraded Version,Printing Volume (4.9”x4.9”x4.9”)


 

Component 2: The Control Box



3D printer control boxes are often an overlooked part of the equation when shopping for a first 3D printer. When I was first shopping for my machine I didn't really think much about this part and looking back, I wish I had known more about it. While not a make or break part of buying a printer, the control box can definitely affect the form factor and makes a difference in how your printer fits into your work-space.

To get started, we should first cover what a control box is. In the simplest terms, a 3D printer control box contains all of the brains of the 3D printer. This part of the printer houses all of the key electronic components that makes the printer work. It reads the 3D model data and then sends signals to the motors to move the correct way.

In this section we will cover a little bit about each of the components that make the control box work, as well as discuss form factor for the control box itself.

The Screen

First on the list of components is the screen. Depending on the price range you are looking in, printers have all different types of displays. There is everything from small, 2-inch black and white LCD displays to much larger full color touch screens. While all of these deliver a very functional experience, there are a few considerations when deciding which one you go with.

Style 1: Black & White LCD Screens

Small, simple LCD screens are the most basic design you can find and are by far the most common. They are inexpensive but still provide all of the key information you need to operate your 3D printer. Because these are not touch screens, there are other input methods needed to interact with your machine.

Oftentimes with an LCD display you will have a small control knob that twists and clicks in. By rotating the knob and clicking on options you are able to go through various menus and make the machine operate. It can be a little clunky at first but after you've spent several hours working with your machine, this simple interface works extremely well in my opinion. This is the interface I have on my 3D printer and over time I have found it extremely easy to use and fast once I learned we're all of the various functions were.

Overall, a small LCD with a control-knob style interface should not scare you away. Sometimes simple can be nice!

Style 2: Full-Color Touch Screens

Next, I’ll move on to the larger, full-color touchscreens. These displays are a little bit more advanced and offer a more direct interface then spinning a knob around. While I personally like the simple LCD display, touch-screens are extremely easy to understand and anyone who uses a smartphone will instantly know how to work the machine. Because of this I think the learning curve might be a little easier and a newbie will feel less intimidated because it's a familiar way to interact with a device.

This type of display is also good for people who don't feel like learning the scroll wheel method when selecting items like someone would on the LCD screen style of control box. Overall, these small full-color touch screens are a really nice luxury and can make your 3D printer feel like a futuristic piece of technology. The main disadvantage is the price though, as usually these screens are found on more expensive printers.


Internal Access:

The next part of the control box to be aware of is access to the motherboard and wiring. Hopefully you will never have to open up your printer and do a little bit 3D printer surgery as I like to call it, but since it’s a possibility it’s always good to be aware of this. The control box contains all of the essential electronics, so there's a chance that something may go wrong with a component inside of it. Because of this, it's always a good idea to at least know how to access the inside of the control box.

I would like to issue a warning at this point. These control boxes also contain power supplies and should only be worked on when the machine is not plugged in. You are dealing with electric appliance what should never be plugged in when you are working on the internals.

Unfortunately, information on how to get inside the machine is not likely to be readily available on the product information page on Amazon. You will have to do a little bit more research on the specific model of printer you are looking at.

I would recommend looking up motherboard replacement tutorial videos for the specific model of 3D printer you're looking at on YouTube to get a good sense of what it takes to get into the machine that you are buying. If it seems like other owners are having trouble just getting it open, you may want to make sure you're buying an extremely reliable printer that probably wont have a break-down, or take a look at a different printer in the same price range with better access to the internals.

Control Box Form Factor

The final part of the control box that we will discuss is the form factor. In other words, how is the box designed? Fortunately this is something that seems to be getting better and better every single day with each new 3D printer model that's released. In general you will find two styles of control box formats that all of the parts we discussed fit into.

Form Factor One - A Separate Box:

Some printers have a control box that sits off to the side and is connected to the rest of the machine by a bundle of cables. This is what my printer has and what is most familiar to me.

Advantages: This style of control box is overall pretty accessible. If you need to make a repair or adjustment inside the control box, it's easy to work on a small box versus having to dismantle a larger part of the machine. I have had to open my control box on a couple of occasions, and being able to easily move it and flip it over in different directions really helps to make the process easy.

Disadvantages: One thing I am not crazy about with a separate control box is the fact that it adds some additional clutter. If you are working in a small space and have limited room for wires. This just creates an additional bundle of wires that you have to worry about. Also, the cables are usually fairly short so it means the control box will probably have to sit directly next to the machine, making the overall footprint of your 3D printer larger.

Form Factor Two - An Integrated Box:

These offer the same components as the stand-alone control box, but they're integrated, usually fairly elegantly, into the overall 3D printer structure.

Advantages: The advantage of this is, in my opinion, a much nicer looking and more organized machine. Because the control box is integrated into the machine itself, you don't have to worry about extra wires dangling off the back. Also, a separate control box will take-up extra space on your shelf, desk, cabinet, or wherever your printer ends up living..

Disadvantages: The main disadvantage I can see with this, unlike the independent control box, is the fact that it may be more difficult to gain access to essential pieces within the control box for repair. Depending on how the controls are integrated, you may end up having to take apart a good portion of the printer or lie the entire printer on its side to access what you need. With all of that said, this style of control box usually comes on more expensive, higher quality 3D printers. because of this, I would expect that the need to have access to open the box and make repairs is much lower than a truly budget level machine.


Component 3: The Print Bed


The bed of the printer is where the rubber meets the road so to speak. The bed of a 3D printer is the big, flat part you see as a focal point of the machine. This is the surface where the extruder puts material down in thin layers to make the print. There are a few features of the print bed that can define how your printer functions and what its overall capabilities might be.

Size

The first thing to notice about a 3D printer bed is the size. The area of this surface along with the size of the frame overall will determine how small or large your printer can print. A large frame with a large print bed will give you big prints. A tall frame with a small print bed will get you prints that can be tall but are not very wide.

When buying a printer, think ahead to the types of things you'll be printing so you can get the correct sized for your needs. You will often hear the total area of printable space the "build envelope" or "print envelope". This is the maximum size the printer can go to in all directions (X, Y, and Z axis).

Surface Material

The next thing to consider about a 3D printer bed is the material it is made of . Or, more accurately, consider the surface you will be using to cover the bed your printer comes with.

Generally, these printer beds are metal with a thin sheet of plastic over the top. This sheet of plastic is the surface that the 3D print will stick to. All 3D printer beds have a smooth finish that prints can be made on. While it's possible to use this surface out of the box, I recommend a couple of options that will improve the life of your printer and will lead to better prints. Basically, the "stock" surface will get covered-up via a few different methods. These are what you want to consider as "add-on" purchases when getting a new printer.

Replaceable Surface Sheets

My personal favorite method to ensure my printer bed is maintained well, is to get replacement surface sheets. These sheets can be purchased in multi-packs and require little effort to install or replace. The sheets are thin plastic, with a removable backing. Basically, they're just giant stickers that you put down on the bed of your printer.

A smooth plastic surface on the top gives 3D prints a good place to be created, and the bed of your printer stays protected. Over time these sheets can wear down, but they can simply be peeled-off and replaced with a new sheet. It's basically like getting an entirely new print bed each time you install a new sheet!

You can check out some of my favorite brands on Amazon. My number one pick is BuildTak which you can find here. Another highly recommended brand is DOBSTFY, which you can see here. One nice feature of this material is it can be easily cut to fit whatever size and shape your printer bed may be.



Glass Surfaces

The other option that people go with is to add a small pane of glass and print directly on that. I personally have not used this method but many people swear by it. Having a perfectly smooth surface can help generate great quality results. Another nice trick is if a print gets stuck to the bed, which can happen surprisingly often, it's easy to remove the glass from your 3D printer with the print still attached and put it in the freezer for a little while. The temperature difference to the glass and the plastic 3D printed part should cause the print to pop right off.

One important note is to make sure you're not just using any old glass. It's important to pick up Borosilicate glass that is specifically used for 3D printing. It is intended for use with high heat and will not warp over time. As usual when doing anything with glass though, BE CAREFUL.

While a glass surface can deliver amazing results, the downside of this material is that you have to make sure to get the exact right size glass for your printer bed. Unlike the plastic sheets, this can not be cut easily.

Not to mention it's probably not very safe to cut unless you have the proper tools and training. Fortunately these glass surfaces can be picked-up relatively easily online and if your printer is even somewhat popular you can probably find a size to match.


Heated Beds

The next feature to look at with a printer bed is whether or not it has a heated surface. A heated bed is not an absolute necessity, but there are several reasons why you will likely want this feature. These reasons all stem from the fact that a heated surface keeps the printed plastic from cooling down too quickly.

In general, materials expand and contract as the temperature changes, this holds true for 3D printers as well. 3D printers work by melting plastic and then placing the melted plastic in an exact location. As this hot plastic cools down it contracts, becoming smaller. This temperature change, especially if it happens too suddenly, can cause several problems with the quality of a 3D print, and in many cases may make it so the entire print just fails.

This failure can happen when a 3D print cools too quickly because there is no heated bed. As the cooling print contracts, the edges can start to peel up from the bed. If this happens, the surface Bond between the 3D printed item and the bed of the printer gets weaker and it can cause the entire print to pop off of the bed before the print is complete.

This heating and cooling difference affects different materials in different ways. For example, PLA filament (which is the most common for use in home 3D printers) is a material that prints at a slightly lower temperature, and doesn't expand or contract too much. So you should be able to get away without a heated bed.

ABS plastic on the other hand, has a much higher printing temperature and can contract significantly as it cools. This extreme difference makes it so that a heated bed is basically a necessity for ABS plastic if you want to avoid the dreaded warping.


 

Component 4: The Extruder



As you begin your 3D printing journey, “extruder” is a word to get familiar with. The extruder is a critical part of the printer that takes raw filament, melts it, and deposits it where it's needed. It is a tiny machine within itself, and contains multiple parts. For simplicity purposes we'll be talking about the extruder as a single unit even though it has multiple parts.

With most hobby-grade 3D printers, the extruder assembly moves in sync with the bed to build up layers of plastic where it's needed to create the model that's being made. This movement happens along a left to right, or front to back axis ("X" or "Y" axis); and an up and down axis ("Z" axis). Sometimes, however, the extruder will be moved in all three directions depending on the printer. As discussed earlier in this article, the frame style of the printer helps to determine how the printer functions and moves, so look to that for some idea on what to expect.

The extruder itself is fairly simple. Plastic filament is pulled in to one side by motorized gears. At the bottom of the extruder assembly is a nozzle. Within the extruder, the filament is heated up and melted, then pushed through the nozzle at the bottom and on to the printer bed. Imagine it like a very tiny and precise glue-gun.

When it comes to purchasing a printer, you will want to research how easy it is to deal with a few common extruder issues. The easiest way is to search for a guide or YouTube video about the following issues on the specific 3D printer you're looking to buy. Read a few of these articles or watch a few videos to get a rough idea of how difficult it might be to solve common problems. The following issues are what most commonly have happened to me and what I recommend you search for.

Ease of Clearing Clogs or Jams

A very common issue with extruders is a clog or jam. While there are several reasons for this happening, the most important thing when you're getting started is to learn how to fix it. It is a problem that will happen on occasion when your are shopping for a beginner 3D printer, so you may as well learn to fix it.

When reading a guide or watching a YouTube video, you should see a fairly simple process. If you notice someone is having serious trouble with removing a basic jam or clog, you might want to stay away from that model of printer. It's likely you'll be having to remove old filament or fixing some small jams in any printer you buy, so you may as well find one that's easy to fix when it does go wrong.

Swapping Filament

Another common task that you will be doing when 3D printing is swapping out filament. Every time you want to change the color of what is being printed, or if you just plain run out of filament and have to load something new; you will have to deal with this process. It's a 100% guarantee that you'll be doing this process (unless you decide to hire your own 3D printer butler!).

Most of the time, it can be as easy as placing the filament in a hole, and having the printer take care of the rest of the work. Sometimes however, filament changes might not go as smoothly. In those cases, you will have to treat the new filament installation like a clog or jam as described above.


 


Conclusion

As you can see, while 3D printers seem like amazing, complicated pieces of technology, they're really just several simple components that work together.

First, the frame of a 3D printer not only defines the amount of space it will take up, but also how the printer moves and generally operates. For home-use printers, there are a couple very popular styles to look out for.

Next, the control box acts as the "brain" of the 3D printer. In addition, this will be your main interface with the printer and it contains controls, as well as a screen to monitor status and navigate menus.

After that, the print bed is the surface the printer puts plastic on. It's a smooth surface that needs to be well-maintained and some offer features like heating to allow for more printing options.

Finally, the extruder is where the printer melts plastic and pushes it through a small nozzle to deposit the plastic where it needs to go to build-up the 3D model. Lots of pieces come together to make this work, so a reliable or easy to fix extruder should be high on the list.

All of these parts are not that complicated individually. At the end of the day though, these components come together to form a pretty fantastic little machine. 3D printers are becoming more and more commonplace, and now you have a wealth of knowledge about how they work to make adding one to your own home a much easier process.

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