Fused Deposition Modeling(FDM) is also called Fused Filament Fabrication(FFF). This type of FDM 3D Printer is Widely used in the market.
In this blog, we will see all the things about Fused Filament Fabrication 3D Printer. So by reading this article, you don’t need to go to another place. This blog takes your 5 to 10 min to read.
You can directly jump to a specific topic by below table of content.
Table of Contents
“Fused Deposition Modeling”
Before starting to learn fused deposition modeling we will first see that different types of 3D Printer working principle.
Types of 3D printers
There is a different type of 3D Printer available in the market. All 3D Printer working on the different working principle and having different advantages and disadvantages. See the below main types of 3D Printer.
Extrusion (Deposition of matter)
Extrusion (Fused Deposition Modeling FDM)
The extrusion printers are the most common and possibly if you have seen a 3D printer will be of this type.
They are known in the 3D printing community as FFF(Fused Filament Fabrication).
The operation is very simple, a nozzle takes out material to go creating the layers.
These desktop printers are ideal to have at home and those that are discussed more thoroughly in this tutorial.
The FDM printers are the most economical. Not only when buying the machine but in terms of maintenance and consumables.
They work with all types of thermoplastics, plastics that after melting re-harden. Filamentrolls or coils are used where the price of the material is very cheap. One kilogram of pieces will be about € 20.
This type of printers is used both for personal use and in small and large companies. There are printers of all sizes but the most common are printers to make objects that fit in the palm of a hand.
The pieces have a finish where it is appreciated that the object has been manufactured by layers. Therefore, these printers are perfect for prototypes or parts that do not need a very high aesthetic.
The precision of the movements that the printer can make and the thickness of the stroke it can make (0.4mm).
In the precision of the movements, the difference between the minimum layer height (0.006mm) and the X and Y axis (0.02mm) is differentiated.
To create the layers use photosensitive resin. This resin cures (hardens) with a certain type of light, usually ultraviolet.
Instead of depositing material to make the layers, light is emitted on the resin to “harden” it.
There are three types of printers: SLA, DLP, and CDLP.
Resin printers are a bit more expensive than FDM printers. These resins allow giving greater precision than FDM Printer.
It is ideal for jewelers, dental technicians or model makers .
The resolution is given by different factors.
The precision of the movement of the Z-axis
Thickness of the line that can be made
For example, if it is an SLA printer it will depend on the thickness of the laser(0.05mm). If it is DLP it will depend on the resolution of the image (0.03mm).
In the precision of the movement, only the minimum layer height (0.006mm) is identified. In this type of printers, the two types of resolutions are very important.
These printers work in a similar way to resin, but instead of curing resin they “fuse” the powder to make the layers.
There are printers that drip chemicals for the powder to bind. Others that use physical energy such as a laser or even the combination of chemistry and physics.
The great advantages of this technology are that it can print on different materials and not having to print support structures.
They are usually much larger and more expensive than the others.
In short, there are many types of printers but all start from the same principle.
Go joining layers one on top of the others. Each printer has its good and bad things.
It can be printed on plastics, ceramics, metals or even paper. Some are affordable and others are exaggeratedly expensive.
How does 3D Printer work?
There are many types of 3D printing, but all printers use the same working principle. Be part of a CAD design or computer design that is divided into layers or horizontal sheets.
The printer “prints” a layer and then repeats the process on top of the previous layer, and so on until an object is created.
To understand how it works you can imagine a baker making a cake that has several layers of height. To make the cake use the pastry sleeve and cover the entire layer, then place a layer of cake on top and repeat the process.
3D printing is the same, go stacking layers on top of each other but automatically.
The limitations, support structures
There is a problem creating an object by layers. You always have to deposit material on top of something, you can not print on air.
If a palm tree is printed like the previous image, the following happens:
There comes a point where the printer has to print the palm leaves. These sheets have no point of support because they are hanging upside down.
To be able to print this palm the printer must be able to leave material floating in the air.
So cannot all kinds of objects be printed? Yes, yes you can but you have to know how. To be able to print objects that have cantilevered parts there are three tricks:
The easiest thing is to add support structures. A kind of scaffolding is designed to hold the cantilevered parts. The programs that are used to make layers do it automatically.
Downside is that you add material to the process and this takes more time to print.
The drawback is that you then have to remove these supports and they can be in inaccessible places or leave marks on the object.
Orient the Object
That is, place the piece so that all layers always have the support and is easier to print.
Divide the object
In these process divide the object into parts and join them once printed. There are cases that the result of printing will be much better in this way and objects with more quality remain.
You can see below image for better understanding.
How does FDM 3D Printer work?
All printers work by dividing the object into layers. The difference between them is the way to generate the layers and what materials they use.
In this case, an extruder and thermoplastics are used as raw material.
Extrude means to shape a plastic mass by making it come out through an opening. The material goes through a circular opening and comes out in the form of thread, as in a pastry bag or in a tube of toothpaste.
Thermoplastics is a material that at relatively high temperatures, becomes deformable or flexible, melts when heated and hardens when it is cooled again.
In short, the FDM 3D printers heat the plastic in the form of a filament, to make it go through an opening. As the material comes out, the printer moves to “paint the layers”. Paint one layer on top of the other until you get a three-dimensional object.
With the following example, you will understand it perfectly.
You have a 3D design of a cube. The printer needs to have the object divided into layers or laminated. Once laminated, the printer will “paint” layer by layer, one on top of the other until completing the object.
The first layer you paint is a filled square. Then he paints squares one on top of the other until he makes a cube. In the example, to take less time to print, the inside of the cube is not solid.
Parts of FDM 3D Printer
There is a number of Parts is required to make Fused Deposition Modeling 3D Printer.
3D printing is the sum of many very simple little things. The problem is that they are many things, therefore it is important to go little by little and understanding what each thing has a function.
Here we will discuss important parts only.
The extruder is the “brush” of the 3D printer, one of the most important parts.
You can differentiate two parts. A nozzle that is heated called hot end, responsible for heating the material. And another part composed of a system of gears and bearing that pushes the filament and makes it pass through the nozzle.
It is the Part of the extruder responsible for heating the filament. It is composed of the following elements:
Heatsink or “Heat Sink”
A heatsink is an instrument that is used to lower the temperature of some components.
In the extruder, the heatsinks are usually accompanied by a fan.
The problem of heating is the dissipation of heat. If the heat rises, it makes the filament softer on the top. When heating on the top, trying to push the filament is more difficult and can give printing problems.
Therefore, it is very important that whenever the printer is running, the heatsink fan is on.
Thermal bar or ” Barrel”
It is thermal bar has the function of guiding the filament to the tip.
It makes the union between the Heat Block and the filament thrust system.
Some use a Teflon tube (PTFE) to improve the sliding of the filament. If you use materials that need a lot of temperatures can cause problems, since Teflon starts to melt at 270ºC.
There are versions for the filament of 1.75mm and 3mm.
Heating Block or “Heat Block”
The heating block is the part responsible for heating and maintaining heat.
It makes of union between the mouthpiece and the thermal bar.
To heat this block an electronic resistance is used. To know what temperature the block is in, a temperature sensor is used.
Therefore the block has holes to insert both the resistance and the temperature sensor.
The most common is that it is aluminum although you can find other materials. Each material has a coefficient of thermal dissipation. That is, each material has the property of maintaining heat.
If a material keeps the heat better, it will be easier to stabilize at a certain temperature. However, it will take more time to reach this temperature.
The nozzle gives the diameter with which the material will be extruded.
If it is spoken in terms of painting, it comes to represent the brush with which the layers are painted.
It is necessary to differentiate nozzles for the filament of 1.75mm and for 3mm.
As with the heater block, nozzles of different materials can be found. The most common is to use brass nozzles for the price.
There are nozzles with different threads that adapt to different extruder models. With finer nozzles, you can make smaller details. With larger nozzles, you can print extrude more material in a single pass and print faster.
Types of Extruder
There are many types of extruders on the market. You have to know what to use filament of 1.75mm and 3mm.
Both the thermal bar and the nozzle must be conditioned to the diameter of the filament. The part that pushes the filament too. Here is a list of the different types of extruder:
The first extruders that were used were formed by a system of printed gears.
In this way, it was possible to give more strength to the movement. It was mainly used for 3mm filaments.
The problem with this type of extruders is that they take up a lot of space.
To part, when using printed pieces has a certain tolerance and wear. Printing with materials that need a lot of heat can give problems.
Direct Extrusion or “Direct Drive”
An evolution of the extruders with gears are those of direct extrusion.
Direct extrusion refers to the motor pushing the filament directly.
A toothed pulley or “Hobbed Pulley” is placed on the motor shaft. This pulley pushes the filament with the teeth.
To ensure that the filament does not slip, a bearing is used on the opposite side to apply pressure.
The main advantage of this type of extruder is that it occupies less space. It is mainly used in filaments of 1.75 mm since these require less force to be pushed.
An alternative that is used mostly in delta printers is the Bowden extruder.
A Bowden extruder can carry both a direct extrusion system and gears.
The difference is that separates the drive system (motor) of Hot End using a PTFE tube.
In this way, you only need to move the Hot End and not the entire engine.
It is possible to reduce the weight considerably, making it possible to print at higher speeds. It also makes it easier to change the Hot End.
The main problem is when trying to control the thrust of the filament. Having the point that pushes the most separated to the one that makes resistance (nozzle) is more difficult to control.
You can see the below image for Extruder Difference.
In 3D printing, the structure is the part responsible for joining all the parts of the printer and allowing the movements of the axes.
Different structures allow different movements, but it is very important to have a robust structure. A weak structure transmits vibrations and forces printing at slow speeds.
A 3D printer is a mobile system that meets certain characteristics. The extruder is always oriented downwards and can be moved with respect to the printing surface in the three axes (3 dimensions).
To be able to move the extruder can be done in several ways. You can use linear movements, one for each axis. Also rotary movements or the combination of linear movements with rotary.
These printers receive this name due to the coordinate system they use for movement, the Cartesian.
They are the most common type of structure in FDM printers.
They use linear movements to position the extruder. If you notice, to move the extruder from left to right or from front to back (X axis and Y axis) use straight movements. To change the height too, but instead of moving the extruder moves the printing surface.
There are structures, such as the Prusa i3, that use more than one motor to run an axle to move an axle. Everything depends on the type of axes and distribution of the structure. There is a system known as CoreXY and another system called cross rods.
One advantage of Cartesian printers is that they are more intuitive. It is easier to detect a movement failure. For example, if the X-axis fails, you will see right away that the extruder does not move from left to right.
The structures are scalable but you have to keep in mind the relations of force. That is to say, if I make a bigger printer, I will need bigger shafts and motors that allow making more force since they have to move more weight.
Another advantage is that you can get structures that can make a lot of force in the tip, most CNC three axes use this type of structures.
Printers based on the delta robot also use linear movements to position the extruder.
The extruder is suspended above, positioned by three articulated arms that slide up and down on vertical guides arranged in a triangular configuration.
Combining the movements of the three articulated arms can be positioned in the extruder in any position of space. For example, if you want to move the extruder upwards, move the three articulated arms at the same time. If you want to move the extruder to the side, one articulated arm will rise and the other two will lower.
This system has a disadvantage, it can not load with much weight in the extruder. In return, much higher speeds are achieved.
Climbing this printer is easier, especially in height. Another characteristic they have is that the printing surface is circular. Therefore, it is ideal for making cylindrical objects that are quite tall.
These printers are named because they use polar coordinates to print in 3D.
Coordinate sets are described with angle and length. This means that the printing bed rotates, and the extruder can move up, down, left and right.
Like the delta, the printing surface is circular.
Having a spinning base is ideal for printing objects following a spiral. That is, copying objects that are made in clay lathes for example.
The main problem with these printers is precision. By moving the printing surface in a circular manner, there is more precision in the center than at the end. Therefore it is not a good idea to scale enlarging this type of printers.
The Scara system is a robot that is known for its fast work cycles, excellent repeatability, high load capacity and wide field of application.
To position itself in the X and Y positions, it uses 3 motors making rotary movements.
The cost is considerably higher than other systems.
One feature they have is a work area in the form of a half moon, although only a square area is used to print as a printing surface.
Unlike the polar, this does not lose accuracy depending on the position.
It is also capable of supporting and applying large forces in the extruder, giving the possibility of using it as a CNC.
A robotic arm is a type of mechanical arm, normally programmable, with functions similar to those of a human arm.
At the tip, place the extruder. I have decided to add this type of structures since all 3D printer structures are based on robotic systems.
The great advantage offered by using a robotic arm is the degrees of freedom.
It allows placing the extruder in different angles, not only in a vertical position. This way you do not need to print layer by layer. The problem is programming, which becomes much more complex.
All conventional structures are designed to work layer by layer. This ensures that the extruder will never collide with the part. Using systems that allow more than three axes requires the use of complex programming systems.
The first layer is the most important since the whole object is going to be built on it.
Having a printing surface that does not have adhesion can be a big problem.
The most common is to heat the surface, with a warm bed, to add adhesion.
Many materials need a warm bed to be able to stick to the surface.
The first condition that a 3D printing surface must meet is that it must be as flat as possible. If the surface is not flat there will be areas where the extruder hits the surface and other areas where the extruder is very high.
Once the object has just been printed, it is stuck to the surface. Being able to remove the surface makes it easier to detach the piece.
If you try to detach the piece directly on the surface, you will most likely lose your shoes. Therefore, the idea is to use a warm bed and a surface on top that can be removed.
Calibrating the surface is to make sure that the plane that forms the surface is completely parallel to the movements of the X and Y axis.
Heatbed or hotbed
In the beginning, aluminum plates with resistors attached below were used to heat the surface.
The problem is that the heat was not distributed evenly. It was hotter in the contact areas with the resistance.
Later they were replaced by PCB plates (electric circuit boards) with very thin tracks.
That is to say, very fine “cables” are used that, when passing electricity, are heated (like a light bulb). They are some plates of 20 × 20 cm approx.
The problem with these beds is that they are made on a printed circuit board, some fiberglass resins. These plates are flexible and warped. On small surfaces, there is no problem but when you want to use on printers with a larger surface can give problems.
An alternative to avoid warping is to use an aluminum surface. As with heated blocks, they maintain heat better and distribute heat more evenly. This type of surface is ideal for beds of 20 × 30 cm.
When dealing with printers that want to heat larger surfaces, a silicone bed is used. These silicone beds can be made to measure and stick on any surface. You can also join hotbeds with each other, but I recommend that the bed is in one piece.
Electronics represents the brain of the 3D printer. It will be responsible for deciding the movements and actions in each moment.
Whenever an electronic circuit is used that has to interact with the environment, it will require sensors and actuators.
A sensor is a device to find physical or chemical quantities and transfer them into the electrical property.
An actuator is the opposite, from electrical signals generate physical or chemical magnitudes. For example, an electric motor that transforms electricity into motion.
You already know that there are parts that are heated, therefore resistors and temperature sensors (thermistor) are used. Also, it is a system that moves, therefore it needs engines. That’s it, the printer does not need anything else.
Microcontroller: It is a programmable integrated circuit, capable of executing the orders recorded in its memory. That is the brain of the printer.
Heating system: The printers have a resistance as actuators to heat the extruder and a heated bed. Temperature sensors are used to determine the temperature of these components.
Movement system: As motors are the motors. The minimum will be one for each axis and another motor for the extruder. The movement part uses sensors to know what position it is in. The most used are the end of a career.
Interface: It is the part of the electronics that allows the user to exchange information with the printer. The most common is an LCD screen, but it can also be through a computer using a USB cable, WIFI or Bluetooth.
Power supply: It is usually used as a 12V DC source with 20A. Although the power of the source will depend on the printer (if it has a hotbed or not, the number of extruders).
The easiest and most economical thing in open source is to use an Arduino board and a RAMPS module.
The plates Arduino are developing plates, microcontrollers with inputs and outputs.
For all types of projects that require an electronic part, using an Arduino board is a great solution. In the case of 3D printers, the Arduino Due model is used.
The RAMPS module is an adaptation plate or shield that is placed directly on top of the Arduino.
The microcontrollers work at 5 volts, the same “electricity” that goes through a USB.
In order to move the motors and to be able to heat up, as this requires more “electricity”, the input and output signals have to be adapted.
The RAMPS has this function, adapt the signals that enter and leave the Arduino to the sensors and actuators.
There are many alternatives and already pre-designed plates to use in 3D printing. They are a combination of Arduino and RAMPS all in one. Many of these plates are Open Source so you can find a lot of information about them.
You can even download the designs and make the modifications you want. In short, the microcontroller (Arduino) is the part that thinks and to be able to communicate with the rest of the elements it needs adapters (RAMPS).
The system that the printer uses to heat is as simple as possible. It uses a resistance, a very thin filament that when the electricity goes on heats up.
As you already know, the hotbed works with the same principle. The same thing happened with the incandescent light bulbs, which apart from giving light could not touch what they burned.
To understand how the temperature regulates, imagine that you have a heating device. This device can only be switched on (maximum heating) or switched off.
If you want a temperature of 30º and you are at 20º turn on the heater. When you are at 31º you turn it off and let it cool down. When it reaches 29º, you turn it on again until it reaches 31º. In this way, you can maintain a temperature of about 30º.
The temperature regulation system of the 3D printer works like a thermostat.
Therefore, you need temperature sensors. One for the hot bed and one for the extruder.
Step motors are used to move the different parts.
That is, they are not controlled using the speed they spin like DC motors. The step is the minimum movement that the motor can make.
Imagine that an engine every time it makes a step turns 45º. If I want the engine of a whole round (360º) I will need that of 8 steps.
What happens with this type of engines. Knowing how much they have moved is very easy, the movement is related to the number of steps. But the problem comes in knowing the starting point, in what position it is before moving.
The printers use the motors to move the extruder. The extruder moves along the 3 axes.
To know the exact position, a starting point or origin ( Homing ) is set. The printer is assigned a reference point, usually when the axes are in the zero position.
To go to origin or homing, the printer uses some limit switches. The limit switches are nothing more than switches (buttons).
The first thing the printer needs to move is to know the position it is in. As he does not know what position he is starting to move so that he approaches the end of the race.
In the case of the X-axis, the extruder moves to the zero position, it will go to the left. Once the end of the stroke is reached, the printer already knows that it is in the 0 positions of the X-axis.
The same thing happens with the Y and Z axis. As you know where the extruder is, the printer can move to the position that you want.
For this reason, before printing a file the printer goes to origins, the starting point.
So with stepper motors and limit switches, you can make precise and economical movement systems.
The only detail that needs to be added is to adapt the Arduino signals to the motors. Drivers or drivers are used.
3d Printer Software(FDM)
When you talk about programs or software for 3D printing you have to differentiate them by the utility. First, we find 3D design programs.
These programs allow you to create and modify a file to be able to print it.
Programs exclusively of the printer can be differentiated two types:
The 3D files that are used are STL format. These 3D files are transformed into GCODE through the laminator. The GCODE file is interpreted by the printer thanks to the firmware. That is, printers use GCODE files to work.
The firmware is the operating system of the printer.
It is the program that is installed in the microcontroller to determine the orders. If the microcontroller is the “brain” the firmware is the “ability to think”.
At the open source level, I want to highlight Marlin andRepetier Firmware.
The printer’s characteristics are saved in the firmware.
What kind of movement they have (is Cartesian, delta)
What dimensions does the printing surface have? If you have a hot or cold bed.
The steps needed by the engines are configured.
Even what kind of electronics is being used.
Laminator or “Slicer”
The laminator is the program that divides the 3D object into layers, divides it into sheets.
The 3D printer does not recognize 3D files. The printer recognizes orders, generally of movement.
It is important to know how to use the laminator well since it is very common to think that the printer fails when the file is badly laminated.
If the printer moves well and heats up well, it will most likely get the orders wrong.
Even so, do not worry, there are configurations already made for each material and type and printing. This way you can laminate a 3D file with a simple click.
Program free and open source 3D printers of Ultimaker printers.
It is designed for both beginners and experts.
It has a very friendly and intuitive interface.
For beginners, it comes with predefined profiles.
For experts, it allows you to modify more than 200 settings.
It is a free and open source program.
This program is very powerful and allows to modify many parameters
The interface is not very intuitive compared to other programs
It is one of the oldest and most used programs in the world of open source for 3D printers
The problem is that it is much more complex and is more oriented to expert people.
Repetier Host is free but it is not a laminator itself
It is a graphic environment for 3D printing with a friendly interface.
It serves to connect directly with the printer
You can also change firmware settings directly if you use the RepRap firmware
You can laminate objects using third-party laminators such as Slic3r
CraftWare is a free, fast, easy to use laminator software
It is from the same company as the jetbot printers
This is relatively new and is aimed at both beginners andexperts
It is a good alternative to start since the print settings are described in a visual way
It is the most widely used and recognized payment 3D printing software around the world.
With a cost of around € 150, it can be a good option for companies since it is professional software.
The main advantage it brings is the ability to carry out support structures in a manual way.
FDM 3D Printer File (3D Design)
When it comes to printing in 3D, the first thing you need is a 3D file.
The STL format is the type of 3D file used by 3D printers. It is a very basic 3D file format, so the vast majority of 3D design programs will allow you to export in this format.
If you want to use your own designs try going to the “file” tab and clicking “save as” or “export” of your program.
If you still do not know how to design do not worry, to print in 3D is not necessary. The Internet is full of free databases with 3D designs ready to print.
3D printing in general. You can find a wide variety of files, from kitchen utensils to objects for education:
Thingiverse – Makerbot 3D Database
Youmagine – Ultimaker 3D Database
XYZ Gallery – 3D Database of XYZ Printing
If you are interested in more technical things related to science these are your pages.
NIH 3D PRINT – Collection of biomedical files for 3D printing
NASA 3D – NASA website with files to print in 3D
Smithsonian 3D – Smithsonian website with files to print in 3D
3D files for design programs. Databases designed to import into 3D design files, even if you can find some STL:
Grabcad.com – 3D files for engineering
3dwarehouse.sketchup.com – 3D Designs for Sketchup
One of the most well-known and used websites in the world of 3D is Thingiverse.
Not only have designs, but there are also mini applications that allow you to customize the design. In this way, you can make unique designs without having to know how to design.
You can search by categories or an object directly, but remember that you have to do it in English. Within each model to print there are a series of sections. It is advisable to enter the section of Things Details.
FDM 3D Printer Materials
For FDM 3D Printer wide range of material is available in the market.
It can available in a range of below category also:
At the top of pyramid mechanical property of the material is high.
3D Printed parts output depend on material mechanical property and its accuracy. Most common material are listed in below table.
+ Good strength + Good temperature resistance – More susceptible to warping
+ Excellent visual quality + Easy to print with – Low impact strength
+ High strength + Excellent wear and chemical resistance – Low humidity resistance
+ Food Safe + Good strength + Easy to print with
+ Very flexible – Difficult to print accurately
+ Excellent strength to weight + Excellent fire and chemical resistance – High cost
Benefits & Limitations of FDM
The main advantages and disadvantages of the FDM 3D Printer technology are listed below
+ This type of 3D Printing technology is cost-effective to produce thermoplastic parts and model.
+ FDM Technology is very fast printing process. So lead time will be reduced to make next day delivery
+ Due to availability of Wide range of material, it can be used in many fields
– This technology having low dimension accuracy compared to other technology. So it is not suitable for complex parts.
– Parts output have a layer line visible to our eyes. So Post processing is needed to remove these layer line
– The layer attachment mechanics makes FDM parts inherently anisotropic.
Characteristics of FDM 3D Printer is listed in below table.