Types of fdm 3d printers

3. Delta FDM Printers

These printers are being seen more and more on the FDM 3D printing market. They operate with Cartesian coordinates. This involves a circular printing plate that is combined with an extruder that is fixed at three triangular points (hence the name ‘Delta’). Each of the three points then moves up and down and left and right, thereby determining the position and direction of the print head. Therefore, the manufacturing limits of these machines are defined solely by the diameter of the base and the height of the arms. Delta printers, with a fixed print tray, were designed to speed up the printing process. Another advantage of Delta printers is that they can be resized, without affecting quality. However, they can prove more difficult to calibrate.

4. FDM 3D Printing with Robotic Arms

Robotic arms are most commonly known for assembling components on industrial production lines, especially in large automotive plants. While 3D printing has begun to incorporate robotic arms into their production process, most notably seen in the 3D printing of homes and buildings, this technology still remains in the development stage. Robotic arms are primarily used for the assembly of parts.

Although not a commonly used printing process, this FDM printing method is beginning to see an increase in use. This is because the process is not fixed to a printing plate, making it much more mobile. In addition, thanks to the flexibility when positioning the FDM 3D printer head, it is easier to create complex structures, which are sometimes larger thanks to the length of the arms. It should be noted, however, that the final print quality is still far from that of conventional Cartesian printers, so many companies are working on developing it. Major manufacturers of robotic arms include Kuka and ABB, whose solutions are used by many companies including COBOD and Massive Dimension.

Hybrid 3D printers

Hybrid manufacturing is defined as a combination of additive (3D printing) and subtractive (CNC machining, milling) methods in a single solution. It is a machine that allows the exchange of tools for model creation. In the case of FDM 3D printers that incorporate subtractive heads, most tend to have a Cartesian structure. However, there are other cases, such as the Kraken project, which rely on a robotic arm capable of extruding material, but which also use subtractive methods, making it a hybrid manufacturing project. It should be remembered that any solution that incorporates both technologies will have a higher price tag, although the benefits can be far greater as it expands the capabilities of part creation.

Hybrid 3D printers offer more printing possibilities.

Which type of FFF / FDM 3D printer do you use? Let us know in a comment below or on our Facebook and Twitter pages. Don’t forget to sign up for our free weekly newsletter, with all the latest news in 3D printing delivered straight to your inbox!

The 4 Types of FDM 3D Printer Explained (Cartesian, Delta, Polar & Scara)

FDM 3D printers have existed since the late 1980s, but only in the last decade have become affordable 3D printer options for the everyday maker. Unbeknownst to most, there are 4 different types of FDM 3D printer. So, if you are unsure whether a Cartesian 3D printer, Delta 3D printer, Polar 3D printer, or even a Scara 3D printer is best suited to your needs, this article will explain all.

• This article discusses the different types of FDM 3D printer. We also have an article explaining every different type of 3D printer.

This buyer’s guide analyzes the differences between each of the four main types of FDM 3D printer based on your needs, and recommends the 3D printers we feel are best within each 3D printer type. We explain how each type of 3D printing came to prominence, the advantages and disadvantages of each, and niches that each type of FDM 3D printer fulfills especially well.

Cartesian 3D Printers

Cartesian 3D printers are the most common FDM 3D printer type. Name a 3D printer you like, and it will almost certainly be a Cartesian 3D printer. These were the first printers that emerged from the RepRap 3D printer movement over a decade ago that brought 3D printer prices down from tens of thousands of dollars, down to a few hundred currently.

Fun fact: Cartesian FDM 3D printers are named after the Cartesian coordinate mathematical system first discovered by René Descartes back in the 17th century.

These types of FDM 3D printer follow the exact same mathematical pattern: they rely on X, Y, and Z coordinates to place a print head in the correct place to print the plastic filament.A basic model of how a Cartesian 3D printer operates.

Usually the print head moves on the X- and Y-axes, whilst the print head or bed moves up and down on the Z-axis. Some 3D printers move the extruder up and down for each layer, whereas some Cartesian 3D printers have the print bed move up and down instead. This creates an overall strong printing structure, leading to consistent, accurate and steady prints.

They are simple, reliable and can be easily disassembled and upgraded, leading to a number of excellent 3D printer kits being developed, such as the popular Ender 3.

3DSourced is reader-supported. When you buy through links on our site, we may earn an affiliate commission. Learn more

Best Cartesian 3D Printer Options

This is why many successful 3D printer companies have opted to build Cartesian FDM 3D printers, including Creality, Makerbot, Ultimaker, Raise3D and many more. Though other types of FDM 3D printer have become more popular in the last two years, Cartesian 3D printers are still the main FDM printer type in use today.

For filaments for Cartesian and Delta 3D printers, we recommend the following:

• Matterhackers ABS filament
• Matterhackers PLA filament
• Matterhackers PETG filament

Delta FDM 3D printers

Though not as popular as Cartesian 3D printers, delta 3D printers are becoming increasingly seen as FDM technology advances and becomes cheaper. Popular Delta 3D printers include FLSUN‘s printers, as well as the very affordable Monoprice Mini Delta.

Delta 3D printers involve a circular print bed with a 3D printer extruder featuring three fixed triangular points. Each of these three points can move both upwards and downwards within the cylinder print structure, to be able to place the print head where it needs to be to print.

Delta printers first came to prominence via early RepRap designs, that advanced and became well-loved models like the Rostock and Kossel. Companies like WASP have since taken delta 3D printing to the next level, building some of the fastest 3D printers in the world, as well as delta clay 3D printers.

Overall, Delta 3D printers are very similar to Cartesian printers, though there are some slight differences.

• You can view our full delta 3D printer buyer’s guide here.

Cartesian vs Delta 3D Printers: Comparison

The major difference between these two types of FDM 3D printer is where each printer type can print compared to where the print bed is.

For example, in a Cartesian 3D printer each part can only move in one direction — a certain distance down each axis. However, within a Delta 3D printer, the print head is more flexible and can move in any direction, and instead the print bed stays still.

Delta printers are slimmer and taller — they require more height but also offer the ability to print taller structures as a result. So if you’re printing tall parts, go for a Delta 3D printer. Though Cartesian printers must be larger than the same delta printer to have the same build volume, they are consistent and do not lose accuracy towards the edges of the print area.

These differences create a trade-off: Cartesian 3D printers are considered more accurate, with better quality prints; Delta 3D printers are however considered to be faster. The print quality difference, if any, is minimal, whereas the speed of delta 3D printers is exponentially higher than Cartesian 3D printers.

Cartesian 3D printers are also best for printing flexible filaments like TPU, as they often use direct drive extruders which are considered better for flexibles than Bowden extruders, which always feature on delta 3D printers. So for makers looking to print flexible parts, such as 3D printed shoe soles, tires, door stoppers and other parts, you’ll prefer a Cartesian printer.

If you are choosing between a Cartesian 3D printer or a delta printer, think about whether your priority is speed, or print quality and consistency.

Polar 3D Printers

• Notable polar 3D printers: Polar 3D.

Polar 3D printers aren’t as similar to Cartesian printers as Delta, but there are again some aspects that will seem familiar.

They’re called polar because they use a polar coordinate system, whereby every other point on the print bed is determined by its position compared to the central point in the middle of the print bed. This sounds complex, and is difficult for our brains to compute, as each point is not a nominal place but is relative to this central point.

As a result, instead of the square or rectangle print beds on Cartesian printers, Polar 3D printers have circular print beds that rotate and lift up and down to allow for efficient 3D printing.

Fun fact: though the term polar coordinates is attributed to Gregorio Fontana, Alexis Clairaut first conceived of polar coordinates across three dimensions, whilst Swiss mathematician Leonhard Euler was the first person to develop them.

Calculating distance and angle from the central point, with a print bed that spins itself into the correct position, means that an overhanging structure for the extruder and hot end is not required. The L-shaped Polar 3D printer build (rather than cuboid or cylindrical for Cartesian and Delta printers) is efficient, and means that very little maximum build area is lost, with quite large parts printable on a relatively small 3D printer — a massive advantage if you don’t have much space.

Additionally, Polar 3D printers require just two engines to print, working with just angle and length in calculating print areas. On the other hand, Cartesian and Delta printers typically require 3 engines to power each axis. This is theoretically more efficient in terms of energy usage.

SCARA / Robotic Arm 3D Printer

• Example printer: RepRap Morgan, Dobot 3D printer, house 3D printers

The last, and strangest type of FDM 3D printer, are robotic arm 3D printers, also known as SCARA 3D printers.

SCARA stands for Selective Compliance Assembly Robotic Arm.

If you’ve ever been inside an industrial manufacturing plant, or seen clips of one on the news, you’ll have seen huge mechanical arms, welding metals or assembling parts. These robotic arms, used for 3D printing, are scara 3D printers.

Undoubtedly, these are the coolest looking printers. However, we won’t exaggerate like these are already accessible and you can pick one up for a few hundred dollars — these are not cheap like Cartesian printers yet. In fact, most Scara 3D printer applications are in the building of 3D printed houses and other industrial projects.Robotic arms are increasingly used in 3D printing, especially in large, industrial projects like houses.

Advantages of robotic arm 3D printers include additional flexibility when printing. This is because printing is not fixed to a print plate and is therefore more mobile and versatile, making it easier to print geometrically complex parts. Scara 3D printers move in the most similar way to human hands, and print faster than Cartesian printers.

However, there are trade-offs with print quality in most cases. When 3D printing large cement walls these slight imperfections aren’t an issue, however when printing intricate, small parts, Scara 3D printers cannot effectively compete with those such as Cartesian or Polar 3D printers.

At a certain size, super large 3D printers have to become Scara 3D printers. This is because for printing huge structures, like houses, you have to be able to move the house 3D printer to the location. Cartesian and delta 3D printers have structures around them, with the large cube or cylindrical structures making them suitable for remaining stationery in a factory, such as for rapid prototyping. Scara 3D printers on the other hand are better suited as industrial 3D printers. Huge robotic arms can be moved to the site of the build, as we have seen with house 3D printing projects like Apis Cor, to deposit layers of cement to build walls.

We expect to see more Scara 3D printers in the future for these industrial house-building projects, so keep an eye out.

That’s it! Hopefully our guide sheds some light on which type of FDM printer is best for your printing needs. If you’re still not completely sure, we have a bunch of other great guides and rankings to help you choose, including:

• Best FDM 3D printer.
• Best dual extruder 3D printer.
• Our favorite 3D printers overall.
• The best online 3D printing services

FDM 3D printer

• 1 Description
• 2 General process
• 3 Structural elements
• 3.1 Body
• 3.2 Extruder
• 3.3 Working platform
• 4 Preparing digital model
• 5 Seal
• 6 Application

Description

Fused Deposition Printing (FDM) printing technology has become widespread among individuals and small businesses due to its wide capabilities, relative simplicity and good affordability. The popularity of this method deserves a more detailed description of the process and the printers used. In this section, we will look at the nuances of the design of printers and the application of technology in practice. nine0028

General process

Like all 3D printing methods, FDM belongs to additive manufacturing technologies. The term "additive" is an Anglicism from the word "additive", meaning "addition" or "by addition". The term is intended to separate technologies for the production of complex three-dimensional products that differ from the usual "subtractive" ("subtractive" - ​​"due to separation") methods - milling, drilling, grinding, etc.

FDM can be considered one of the most technologically simple 3D printing methods. The process is based on the successive layering of a thin thread of molten plastic up to the creation of a solid three-dimensional object. A plastic thread wound on a spool is used as a consumable. Occasionally, individual bars of plastic are used. The standard thread diameter is 1.75mm or 3mm. nine0028

The printing process consists of a number of steps:

• Create or import a digital 3D model
• Processing of a digital model for printing with the addition of supporting structures
• Location and orientation of the digital model on the desktop
• Slicing - cutting a digital model into separate layers with data conversion into instructions for the printer, called the G-code
• Direct print
• If necessary, physical or chemical treatment of the finished model

Structural elements

Enclosure

Ultimaker 3D Printer with open wooden enclosure

Many elements are important in the design of an FDM 3D printer that are not always obvious to the inexperienced person. So, the material of the case matters in the event that it carries the load. Many FDM printers are available with wooden cases - this solution seems cheap and unsightly, but in fact it helps to absorb vibrations during printing, which has a positive effect on the quality of the manufactured models. On the other hand, a steel or aluminum frame ensures the durability and impact resistance of the device. nine0028

The open or closed design of the printer also matters. A well-ventilated working chamber is useful when printing with polylactide (aka PLA plastic), as this material vitrifies for a long time. If the printed layers do not have time to solidify and seize, they may spread, or deformation of the underlying layers under the pressure of the upper ones.

On the other hand, many popular materials (such as ABS and nylon) have a high degree of shrinkage. By "shrinkage" is meant the reduction in volume of the material as it cools. In the case of the same ABS plastic, excessively fast and uneven cooling of the applied layers can lead to their twisting, or deformation and cracking of the model as a whole. nine0028

PICASO Designer 3D printer with closed plastic case

In this case, the case with closed cladding comes in handy, allowing you to achieve slow, uniform cooling of the material.

Finally, the shape of the FDM printer can also be linked to the coordinate system used.

Thus, the most popular option is the Cartesian or, more precisely, in most cases, the rectangular coordinate system.

Delta-shaped coordinate systems are gaining popularity recently - such devices are called "delta robots" and offer certain benefits in terms of printing accuracy and ease of expanding the vertical size of the construction area. nine0028

Structural elements and rails are usually made of aluminum or steel. The extruder and platform are driven by belts or screws.

3DPrintBox printer extruder, partially disassembled. You can clearly see the pink plastic thread and the pulling mechanism - two gears with grooves in the teeth

Extruder

The next important element is the extruder, that is, the print head of the printer. These devices may vary in design, but generally contain the same basic components: nine0028

• Thread feeder for feeding the thread into the nozzle
• Nozzle used to melt the filament and extrude the molten material
• Heating element for heated nozzle
• Fan

As a rule, the pulling mechanism consists of gears or screws driven by an electric motor.

Obviously, the electric motor drives the gears to feed the filament into the nozzle. In the nozzle, the thread is melted, followed by extrusion of a viscous material. nine0028

An extremely important point is the sharp temperature gradient between the bottom and top of the nozzle - this is exactly what the fan is installed for.

At the transition of the glass transition temperature, the plastic becomes soft, but not yet viscous, expanding in volume.

3DPrintBox extruder assembled. The electric motor of the traction mechanism is visible (top), double fan (middle) and nozzle with attached electric heating element (bottom)

In this state, the friction of the material with the inner walls of the nozzle increases.

If the length (and, as a result, the area) of this section is too large, then the total coefficient of friction may become unbearable for the pulling mechanism.

Thus, the length of the nozzle section with unmelted filament and the length of the section with molten material do not really matter, but the length of the plastic section at the glass transition temperature should be as short as possible. nine0028

The most effective solution to this problem is the use of heat sinks and fans to cool the filament and the top of the nozzle.

In fairness, the residence time of the plastic in the molten state should also be minimized, since many thermoplastics lose their plasticity after prolonged exposure to high temperatures, and the resulting solid particles can clog the nozzle.

Diagram of the transition of a plastic filament from a solid to a viscous state. The length of the middle section should be as short as possible to prevent problems with material push through

Typically, this kind of problem does not occur in normal, stable extrusion because the nozzle length is too short.

Clogging of the nozzle can occur due to internal irregularities or errors in the manufacture of the thread: the resulting stagnation leads to the gradual formation of grains, which are then carried away by the flow of molten plastic and clog the outlet.

The most common nozzle materials are aluminum and brass. nine0028

Hole diameter may vary, but average is 0.3mm.

Smaller bores allow for higher resolution, while larger bores increase build speed and reduce the risk of nozzle clogging.

Work Platform

The 3D Systems Cube 3D Printer Platform moves in the X and Z axes and the extruder moves in the Y axis

The work platform serves as a surface for building models. nine0028

Depending on the coordinate system used, the platform can be movable or static.

Typically, in printers using the Cartesian coordinate system, the movement of the platform in the vertical plane is responsible for the vertical positioning of the extruder relative to the platform itself.

Some models also add movement of the platform along one of the axes in the horizontal plane, which allows you to slightly reduce the dimensions of the device, provided that the case is open. nine0028

An example of such printers is the popular 3D Systems Cube.

The delta robot work platform remains in place. Positioning of the extruder in three planes is carried out solely by the movement of three manipulators

Delta printers ("delta robots") use static platforms.

The positioning of the print head in all three dimensions is carried out exclusively by the movement of the extruder itself. nine0028

As a rule, the extruder is suspended on three manipulators, whose coordinated movement along vertical guides moves the die.

Asymmetric movement controls the positioning of the extruder horizontally by changing the angle of the manipulators, and symmetrical movement - vertically.

Alternatively, a movable platform and a stationary extruder can be used, but these designs are not yet widely used.

Experimental Quantum Delta Printer uses "inverted" design with moving bed and stationary extruder

A distinctive feature of all Delta printers is the cylindrical shape of the build area. One of the advantages of such designs is the ease of building up the working area. So, to increase the height of the building, you only need to install guides and cables of increased length.

However, even static platforms are not completely immobile. Before starting printing, platform calibration is required, that is, the elimination of a possible tilt. Calibration mechanisms can be either manual or automatic, depending on the printer model. nine0028

In the case of manual calibration, the user will be required to consistently position the nozzle at different points on the platform.

To measure the distance, special templates are used, and in the cases of the most simple or home-made designs, simply sheets of office paper, whose thickness corresponds approximately to 100 microns.

More advanced devices like the MakerBot Replicator use special sensors to accurately measure distance. Tilt adjustment is made by rotating the spring-loaded screws on which the platform rests. nine0028

Calibration of the platform is often carried out with the help of adjustment screws, although most printers help in this task by moving the extruder in succession to different points of the platform.