How to Build a 3D Printer: Getting Started Guide and Tips

Congratulations, you have decided to build your own 3D printer! The process of building your own printer can be a bit daunting to some people, especially with so many choices out there. This article will compare different designs and parts and give tips on construction that will hopefully layout the tools and knowledge you need to know on how to build a 3D printer.


Getting Started

The first thing to do once you decide to build a printer is to decide what type of printer you want to build. This article will assume that you are building a FDM or plastic deposition type printer with three axis. But even with that basic decision, there are dozens of frames and configurations that you could choose from. Let’s start off by looking at the two different coordinate systems most used by 3D printers, Cartesian and Delta. Below is a brief comparison:

Cartesian-based PrintersCartesian Example

Cartesian printers are the most common type of printer on the market and consist of three perpendicular axis that print on rectangular print areas. Typical setups have the extruder controlled by two of the axis and the bed controlled by the third, however some variations exist.

  • Easiest to build and program
  • Most common coordinate system
  • Constant resolution across all axis
  • Rectangular Build volume
  • Easily scaled up or down
  • Requires at least 3 motors

Delta PrintersRostock-delta-robot-3d-printer-1

Delta printers are less common than Cartesian and are made up of three parallel axis all connected to the extruder that print onto stationary, circular print areas.

  • Slightly more difficult to build and program
  • Cylindrical build volume
  • Requires at least 3 motors
  • Resolution varies throughout part, with higher resolutions further out and lower resolutions towards the center
  • Better for larger parts

For desktop printers, Cartesian is usually the best option because they are more compact and have a larger build volume than deltas of similar size. As a printer grows larger, delta printers begin to be more economical. Most building-sized printers being tested are delta printers because they require less framework than a building-sized Cartesian.


The Frame

The frame of your printer is usually the next step. The frame will determine how big of a build volume you will have, how robust and cost effective the printer will be, and how it will look. Below are some common frame materials and examples of printers that use them. Each material is rated by how expensive it is, ease of assembly, strength, and the ability to be modified later on.

Threaded Rod

threaded rod frame

A Prusa i2 with threaded rod frame

Threaded rod is common in early RepRap designs because it is cheap and easily found in hardware stores or online. Typically made of steel, ¼” (M6) threaded rod is usually strong enough for most frames. Threaded rod is usually held together with 3D-printed or laser-cut parts at the joints and nuts. Making sure everything is aligned and square is one of threaded rod’s biggest drawbacks since moving parts up and down the rod requires a wrench and carful measurements. Keeping everything tight is also a challenge, as vibrations from the printer will often loosen nuts over time. Using Loctite is one solution, but makes modifications a lot more difficult down the road. Most printers today only use threaded rod for the Z-axis and not in the frame. The Prusa Mendel printers, specifically the i1 and i2, are good examples of threaded rod frames

  • Cost: 2/5
  • Ease of Assembly: 1/5
  • Strength: 5/5
  • Modability: 3/5

Aluminum Extrusions (80-20)

a MendelMax printer with aluminum extrusion frame

a MendelMax printer with aluminum extrusion frame

Aluminum Extrusions, sometimes called 80-20, are more expensive than threaded rod but much easier to build with. The extrusions used in printer frames have a square cross section, and each side has a t-slot running the length of the extrusion that are used to mount parts to using t-nuts and regular bolts. Assembling aluminum extrusions is as simple as bolting a few 3D printed or laser-cut parts onto them. Frames built with extrusions are lightweight and strong, and it is very easy to add new parts to a printer at any time by simply adding more T-nuts. The biggest drawback of aluminum extrusions are their cost: lengths are either cut to order or come as parts to a specific printer design. The MendelMax series of printers is a good example of aluminum extrusion frames. The extrusions are also available in a small assortment of colors, like silver, black, and occasionally yellow-gold.

  • Cost: 5/5
  • Ease of Assembly: 4/5
  • Strength: 5/5
  • Modability: 4/5

Laser-Cut Plywood

The original Ultimaker with plywood frame

The original Ultimaker with plywood frame

Laser cutters, another rapid prototyping technology, can be used to cut frames out of inexpensive materials like plywood. Plywood frames are cheap and easy to work with, and putting together plywood frames is as easy as putting together a couple puzzle pieces. Every slot and hole for interlocking parts and bolts are already cut into the frame by the laser, but adding anything after the parts have been cut will require hand tools. Plywood parts can be ordered online, or templates can be found to cut your own if you happen to have access to a laser cutter at a local maker space or machine shop. Plywood’s biggest drawback is that it can warp over time if exposed to humid environments or heavy mechanical loads, however for most 3D printers this is usually not a problem. Using 1/8 -1/4 in plywood is usually all you need for a printer, just make sure that the sheet is flat. Printers like the original Ultimaker, printrbot, and Flashforge Creator all use plywood frames

  • Cost: 1/5
  • Ease of Assembly: 5/5
  • Strength: 3/5
  • Modability: 2/5

Laser-Cut Acrylic

A prusa i3 model made from clear acrylic

A prusa i3 model made from clear acrylic

Plywood is not the only laser cut material used to make printer frames, acrylic sheets are another cheap option that can be laser cut into puzzle-piece parts. Like plywood, acrylic is easy to find and have cut. It does not warp like plywood but it is prone to scratches. Acrylic comes in all sorts of colors and is often used with other materials as the joint, replacing 3D printed parts. Acrylic can be modified later like plywood, but hand tools produce a different finish that laser cutters do not produce. Also be wary that when acrylic breaks, it shatters. This is not be an issue for printers under normal use. Several Prusa i3 models use acrylic frames.

  • Cost: 2/5
  • Ease of Assembly: 5/5
  • Strength: 4/5
  • Modability: 1/5
lulzbot mini 3d printer review

The Lulzbot mini has an all-metal frame

Water Jet-Cut  and Other Metals

Water jet cut metals like steel and aluminum are also common frame materials typically found in commercial printers. A water jet cutter operates similar to a laser cutter in that it makes puzzle piece-like parts. Getting custom parts made will likely be more expensive than if you used a laser cutter mostly due to the materials being cut. Some sheet metals are cut and then folded, as in the case of some steel frames. Metal Frames are difficult to modify later on without further machining, although a hand drill may give you some options with thin sheet metals. Some Prusa i3 models have water-jet cut aluminum plates used in the Z-axis, while many commercial printers like the Printrbot Metal, Lulzbot Mini, and Wanhou Duplicator i3 all have metal frames.

  • Cost: 5/5
  • Ease of Assembly: 5/5
  • Strength: 5/5
  • Modability: 1/5 

3D Printed Parts

A prusa i3 that uses acrylic, threaded rod, and blue 3D printed parts

A prusa i3 that uses acrylic, threaded rod, and blue 3D printed parts

You have probably heard that 3D printers can print more printers. These printed parts are usually the corner joints on threaded rod or aluminum extrusions, as well as motor mounts and extruder components. For the frame, PLA or ABS (check out the in-depth comparison of these two plastics) parts are best, for the extruder, do not use PLA because the heat will warp it. 3D printed parts are cheap and easy to replace if they wear out (Mostly because you will have a way to make more yourself at any time). A 1 lb spool of plastic is usually more than enough for most printer designs; and since many makerspaces or a friend will probably let you use their printer for material costs, all the parts you need will be very affordable. If you don’t have access to a printer, there are plenty of online resources for ordering custom printed parts or kits of parts, but this can be a bit more expensive. 3D printed parts are easy to swap out and customize if you have the 3D files to work with, and can be made any color that plastic filament comes in.

  • Cost: 2/5
  • Ease of Assembly: 5/5
  • Strength: 3/5
  • Modability: 5/5

Hardware for Your 3D Printer

A frame is useless without hardware to hold it together and mechanical components to guide or facilitate movement. What follows is a list of essential hardware and some tips regarding them.

Threaded rod

Threaded rod is usually used to move the Z axis on printers. Threaded rod can achieve very precise positioning, but does so very slowly, making it unsuitable for X and Y axis. Delta printers don’t normally use them because of this speed issue. For stability, two lengths of threaded rod are normally used in printers. There is plenty of material to go into with the threads alone, however to keep things brief here are a few pointers: Keeping the threads clean and undamaged is necessary for quality prints; the more threads per inch (or mm) will give you a better resolution in that axis, but will make moving in that axis slower; and you will need nuts to move along the threaded rod.

threaded rod for 3d printing

Linear Rod

linear rodLinear rods are another important component of a printer. They are very straight very smooth rods typically made of steel which the different axis are defined and supported by. Linear rods can be viewed as rails, and two are typically used for each axis. It is important to make sure the linear rods are corrosion resistant and won’t wear down with whatever bearings or bushings you choose to use in order to keep your printer running smoothly. M8 and M10 sized linear rods are typical for most printers. For Delta printers, additional threaded rod is needed for the arms. These rods don’t have to be perfectly smooth like the axis rods, but they do need to be the same length and stiff.

Bearings and Bushings

Bearings and Bushings are the parts that keep the printer moving smoothly. They move on the linear rods because of their moving parts; while bushings need lubrication and are more vulnerable to dust and wear. It really comes down to personal choice and budget for the choice between these.

Belts and Pulleys

Belts are used to drive faster axis, usually the X and Y axis on Cartesian printers and all three axis of a delta printer. Belts should not stretch when tensioned and need their teeth to be matched to a pulley attached to the drive motor.

Nuts, Bolts, Washers, and other Fasteners

The printer isn’t going to hold itself together, you will need nuts and bolts to keep it from falling apart! Many printers use a variety of fasteners so here is a quick rundown of what is common to see and a few tips:

  • Keep to the metric system. Using metric will save you a ton of headaches converting between measuring systems, most printer hardware is already in metric and trying to build an imperial printer may actually prove to be more difficult.
  • Be sure everything will fit. This is fairly straightforward. Make sure you have M5 T-nuts that fit in aluminum extrusions if you are using M5 bolts with 80-20, make sure you have nuts that fit on your threaded rod (for the frame or Z axis), and make sure that the bolts you choose to mount your motors with are long enough and will fit the motors.
  • Use washers. They spread the load of a tight bolt out and are necessary when using metal bolts on plastic parts to prevent cracking.
  • Use zip ties. They may not always look pretty, but zip ties are great for managing wires, holding endstop switches in place, and securing belts.
  • Avoid glue if you can. Using nuts and bolts allow you to fix mistakes, using glue only gives you one chance to get things right. If you want to make sure nuts and bolts won’t come undone from vibrations, applying Loctite after making sure everything fits is an option.

Heatsinks

heatsinks for 3d printersPrinters get hot, and not just at the heating elements. Motors and control boards can get hot if not calibrated correctly. Letting these parts stay hot for too long (say, over the course of several prints) will damage components and cost money to be replaced. Adding heat sinks will reduce the heat building up in parts. They are not usually necessary for motors, however motor drivers will certainly need individual heat sinks. Many control boards come with the heatsinks already installed, so look for heatsinks when choosing control boards.

Print Bed

The print bed is arguably as important as the hot end since it is the surface that all of your prints will begin on. To ensure the best prints, a resilient and flat bed are necessary. The surface you intend to print onto is also very important. Many people start out with kapton or blue painter’s tape, which provide good printing surfaces and just need a flat plate to be adhered to. Common bed materials are aluminum or borosilicate glass because they distribute heat on heated beds and are hard and flat; however thick plywood or acrylic have also been used on non-heated beds for their cheapness and how easy they are to cut to size. For best print results, a heated borosilicate glass bed with hair spray provides a strong bottom layer that pops off once it cools down. Check out this article on bed materials.


The Electronics to Build a 3D Printer

Printers are not just frames and hardware, there are plenty of electronic components that are necessary to get them moving, heated, and even lighted. Here are some recommendations for different key components so that you know how to build a 3D printer.

Hot End

The hot end is one of the printer’s most vital components. It determines or influences what plastics you can print with, what sized filament you use, how long your printer takes to heat up, your max layer height, how fast it can print, and more. when picking a hot end, keep these in mind:

PTFE Hot end

PTFE Hot end

  • What you plan to print with: If you want to print with just PLA and maybe ABS, most hot ends will do. If you want to print with higher temperature plastics, an all metal hot end may be needed. Look at a hot end’s max temperature when choosing to determine what plastics you will be able to print with.
  • The nozzle: Keep in mind what nozzle the hot end uses, and try to make it easily swappable. Most hot ends feature nozzles that screw on for easy replacement if they wear out or you just want to switch nozzle diameter.
  • The mount: the hot end you choose will determine what you make your extruder mount out of. Using a makergear v3 will require different mounting than an E3D or Hexagon, both in shape and materials. Select your hot end based off its capabilities and then find how to attach it to your printer.
  • The filament size: This will determine what size filament you will be working with. 1.75mm is currently the most popular, but 3mm is also a common size.
  • Power requirements: Most hot ends come in a 12 or 24 volt variety. While hot ends are basically resistors and don’t care much for voltage, it is a good idea to make sure that your hot end’s voltage matches that of your heated bed and power supply.

Heated Bed

Heated build plate with plywood support

Heated build plate with plywood support

If you are planning to print just PLA, then you may not need a heated bed. However, using a heated bed is required for most other plastics, and do help with PLA parts. If you get a heated bed, make sure that it is as large as your print area to ensure even heating throughout. Also make sure that the voltage of your heated bed is the same as your hot end and power supply. Regardless of the size of your bed, the heated bed will be the largest power hog of your printer, so it will also determine how big of a power supply you will need. Another good item to get with the heated bed is a thin aluminum plate to help spread the heat. Glass also works, but does not conduct heat as quickly.

Motors and Endstops

Motors get the printer moving, obviously. Almost all printers use stepper motors, and most home built use NEMA 17 motors. NEMA is a standard and the 17 is the size of the motor. NEMA 14 steppers are also used, but the 17 is the most popular size. A well-built printer will not need powerful motors, and NEMA 17s have more than enough power to overcome friction from dirty or poor-fitting bearings and bushings. Each printer will need at least four motors (one for all three axis and one for the extruder), but it is common to see five motors on most Cartesian printers where two motors are used in tandem on the Z-axis

Endstops are just small switches that tell the printer when it has reached one end of an axis. Typically you only need one endstop for an axis, and they are usually placed at the “0” or “home” position of an axis. When a printer homes, it goes to the endstops to figure out exactly where it is. Mechanical endstops are the most common, but optical ones can be used with a bit of extra programming.

Control Board

The Control board is the brain of your printer. There are dozens of options to choose from that come in all sorts of shapes, sizes, colors, and capabilities. Arduino based control boards are the most common on DIY printers, while some Raspberry Pi based boards exist as well. In general, avoid the cheap control boards, these are likely knockoffs from China that will break quickly if they didn’t already arrive broken. These cheap boards will also usually be red in color, so try to avoid “red boards” if your budget allows it. Otherwise, the board you use is up to personal preference and what the board can do, does it have an LCD display output? Can it handle 24 volts like your heating elements, or can it only handle 12 How many Fans can it drive? Can it do dual extrusion? Also see If a particular board is popular among other 3D printer users, a more common board will make it more likely that someone else has had, and hopefully has already fixed, any problems you may encounter.

Other Items

There are plenty of small and optional electrical components that can be included on one’s printer. LED lights, LCD screens, even touch screens could be possible if your budget allows for it. Features like touchscreens may be for more advanced makers, but adding some lighting to your printer or even a webcam can be a fairly simple task with a bit of google searching.

One small component that almost isn’t optional (It is possible to make a printer without it) is the cooling fan. Cooling fans can be used directly on printed parts, or on parts of the printer that produce heat. Many all-metal hot end designs use a small cooling fan to prevent the mount from getting too hot and melting the plastic. 40mm computer fans or smaller work best, and you should try to have at least one for cooling your parts, one on a metal hot end, and one for an enclosed control board. It is also important to make sure the voltages match the rest of your system: running a 12V fan on a 24V will only burn it out, and running a 24V fan on a 12V system will leave it underpowered.

Power Supply

power supplyThe power supply is the heart of your printer, and possibly the most dangerous. Always make sure you know what you are doing when working with electricity and never work on the power supply when it is plugged in, otherwise you will damage your printer and risk serious harm to yourself.

Many people like to use old computer power supplies when they build a 3D printer to save money. This works well but can get very complicated quickly because of all the wires with different voltages running through them involved.  Most users will cut unnecessary wires, but many PC supplies require a specific wire to be used in order for the rest of the wires to work. This is a safety feature and the wire that needs a load on it is usally gray, but can vary from model to model of power supply.

Whatever power supply you get, you need to make sure that it can supply enough power to your printer. You can do a quick estimate of the power used by your printer by looking at the amperage used by different components and adding them up. Motors can use as much as 1 amp, while the control board will use almost nothing. multiplying the amps used by the voltage of your system will give you watts. A 250W power supply should meet most printers’ needs.

Don’t forget to get a switch or make sure your power supply includes one. Once your printer is built, getting is calibrated will involve crashing and strange behaviors; so it is always handy to have a way to kill the power quickly is always useful.

Check out the article by RepRap explaining how to choose a power supply.


Programming the 3D Printer

Like it or not, every printer needs to be programmed. This is a difficult topic to write about, so this section will just cover what to expect when you turn your printer on for the first time.

Most control boards run Marlin, a firmware developed for 3D printers. Follow instructions for your particular board to install marlin, you will almost certainly need the Arduino IDE installed on your computer and a USB cable to connect. Make sure you set proper values in Marlin’s configuration for your printer before you upload (if you mess up you can edit and re-upload it). There are plenty of instructions online to configure your printer so we won’t cover it here.

Common Problems

Below are some common problems you may encounter when you boot your printer up for the first time:

Smoke

If your print starts to smoke when you turn it on, turn it off immediately and unplug the power supply. Check for damage to the power supply and other components, you likely just fried something. If your hot end is smoking when you heat it up for the first time, this may just be steam and is okay if it goes away after a short time. You will only see steam if you built the hot end yourself.

Skipping Motors

If your stepper motors are skipping (trying to turn but not moving), there are a few things you can do. If the stepper is skipping on the belt, then the belt is too loose and needs to be tightened. If the motor is skipping internally (the axel isn’t moving but you can hear it trying to) then there is too much torque on the axel for the motor to overcome. Try loosening the belt slightly to see if it helps. If it is already tightened properly, then the motor is not getting enough power. This can be fixed by adjusting the potentiometers on your control board. Again there is plenty of information on how to do this online.

Motors get hot when running

If your motors are getting too hot when running, then they are getting too much power. Adjust the potentiometers on the control board to reduce the power. It is normal for the motors to be warm to the touch after use.

Motors home in the wrong direction

If you try to home your printer and it starts to home in the wrong direction (away from the endstop), then there is a value that needs to be changed in the firmware. This change is usually just the inclusion of a negative sign.

Printer hits endstop but tries to keep going

If your printer homes in the right direction but fails to stop when it hits the endstop, turn it off immediately  to prevent the motors from wearing out and check that the endstop is actually being pressed. If it is, double check that the endstop is wired correctly.

Printer doesn’t respond

If the printer doesn’t respond, it is likely a firmware issue, double check that the firmware you uploaded is configured correctly.

Computer can’t connect to control board

This is likely a driver issue. Make sure that you have the right drivers and try again. If you still can’t connect, there may be something wrong with the board itself. Burning the bootloader will often fix the problem, if it doesn’t then your board may be dead. Be sure to search for answers to your specific board and problem before giving up.


Essential Tools to Build Your Own 3D Printer

You won’t be able to assembly your printer without some tools. Below is a list of tools that you should have when building your printer and later when you use it. Many are self-explanatory but a few have descriptions for what you will need them for.

  • Screwdrivers and Allen wrenches: for tightening your bolts, be sure to keep these tools around when you’re done to make adjustments as time goes on, you will be surprised how often you have to remove that one troublesome part. Small Allen wrenches can also be used to clear out clogged hot ends.
  • Ruler/Straight edge and square
  • Calipers: For measuring parts and double checking dimension, also very useful in verifying your first prints.
  • Knife
  • Scraper: For removing parts after they are printed
  • Sandpaper: for those parts that are just a bit too big
  • Multimeter: essential for electrical troubleshooting. It should be able to measure at least 24V DC and continuity.
  • Tweezers: For small parts and cleaning up drool from the hot end when you are ready to print               

Final Words

Hopefully, this article has provided you with essential knowledge on how to build a 3d printer. Their will be challenges along the way but they are well worth it in the end. Whether you are dreaming big or small, have high hopes or are just curious about this new technology, I wish you the best of luck in building your own 3D printer!