When we talk about FDM 3D Printers, most of the time we tend to talk about the Cartesian version of the 3D printer. But rarely do users know that there are four types of FDM 3D printers and namely, Cartesian, Delta, Polar, and Scara 3D Printers.
We aim to explain these four versions of the 3D printers for new learners and users. But before we begin to talk about the 3D printers, let us first understand the four coordinate systems on which the printers are based.
This is a universal geometrical term and not necessarily connected to 3D printing but it becomes important to understand this 3D printing concept to understand how a 3D printer works.
According to Britannica, a coordinate system is an arrangement of reference lines or curves used to identify the location of points in space. In two dimensions it is generally represented by horizontal (X-axis) & Vertical (Y-axis) while in three-dimensions it adds a third direction that is perpendicular to both the horizontal and vertical direction, the Z-axis.
So depending on how the 3D printer identifies the different points on the build platform to print the exact design, the 3D printers are called so.
CARTESIAN 3D PRINTERS
Above: Operations of a Cartesian 3D Printer/Video Credit: Mohawk College IDEAWORKS/YouTube
This is the most common type of FDM 3D printer. Cartesian 3D printers are the most popular type of FDM 3D printers across the world. A huge majority of 3D printer manufacturers use the Cartesian coordinate system as it one of the most fundamental coordinate systems used in a wide range of industrial and academic applications.
In a Cartesian 3D printer, three numbers are used to define the position of a point in space represented by X, Y & Z. The X & Y-axis represents the lateral and longitudinal position of a point, while the Z-axis represents the elevation of the point.
Being the most popular type, Cartesian3D printer owners can easily find experts to learn more or get professional help or troubleshoot their 3D printers. It also becomes easy to find replacement parts or a relevant community that own a Cartesian 3D printer like the one the user owns to share resources.
From a user’s point of view, having a Cartesian 3D printer secures you of a lot of stress that 3D printer owners go through during their early learning phase.
For a learner, the Cartesian 3D printer is comparatively easy to learn and easy to build and the structure is quite easy to understand.
Cartesian 3D printers have applications in almost all types of product manufacturing barring applications that are long or tall in size.
Some popular examples of Cartesian 3D printers are those from Ultimaker, Zortrax, Roboze, BigRep, etc.
DELTA 3D PRINTERS
Above: Operations of a Delta 3D Printer/Video Credit: WASP/YouTube
Delta 3D printers are the second most popular type of FDM 3D printer. They can be easily distinguished from a Cartesian 3D printer due to their tall appearance. The unique structure as well is quite intriguing to look at and it’s a joy to watch the Delta 3D printer in action.
The printhead is connected to the three arms of the printer and they all operate in sync to print the layer of the object. The delta 3D printer works in a triangulation configuration and since the three arms work simultaneously, the build volume of the printer is not a cube but a cylinder and the base is a circle.
Instead of positioning the print head according to x, y, and z positions, each of the three arms changes its angle to position the print head on the build platform according to the model. Hitting the precise location is done by a series of trigonometric functions that consider the angle of all positioning arms.
The biggest benefit of a Delta 3D printer is its speed. The high speeds are possible as the extruder does not carry the weight of the stepper motor and this weight reduction is translated into increased speed.
Another advantage of the Delta 3D printer is its height. It is tailor-made for creating objects that are taller and so manufacturers rely on the delta coordinate system when they want to build a 3D printer for manufacturing objects that have a higher Z-axis.
However, delta 3D printers do have a lot of problems. They cannot be used with Bowden extruders and so it limits the use of flexible materials. They also have a smaller base limiting the lateral size of the object to be manufactured. Besides, due to their size, they tend to be delivered in kits and new users find it hard to assemble such kits thereby keeping them away from this type of 3D printer.
Delta 3D printers have applications in building tall products like columns in architecture models, etc.
Some popular examples of Delta 3D printers are Kossel – RepRap, Anycubic Delta, DeltaWasp, etc.
POLAR 3D PRINTERS
Above: Polar3D 3D Printer in action/Video Credit: Tracy & Tom Hazzard/YouTube
Polar 3D printers are not popularly used but still, they offer quite an interesting design. In a Polar 3D printer, the position of a point is defined only by two numbers i.e., an angle in 3D space and the separation distance (or radius) from a pre-defined centre. As a result, they use a circular grid instead of a square in a Cartesian 3D printer.
The build platform of a Polar 3D printer can move left to right – back and forth and can also rotate while the arm (printhead) only moves in the Z-direction. This way, much larger objects can be made in a smaller space.
Polar 3D printers have applications in building tall products like columns in architecture models, etc.
Polar3D is a popular example of a Polar 3D printer.
SCARA 3D PRINTERS
Above: Robots developed by MX3D/Video Credit: MX3D
SCARA or Selective Compliance Assembly Robot Arm is a popular coordinate system employed in industrial robots. A SCARA 3D printer resembles the industrial robots and offers greater freedom and flexibility when printing as it is not limited to a build platform and can move in all possible directions 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.
Currently, they have applications in the construction of structures like bridges, buildings, and even large scale industrial projects.
Dobot M1 3D printer, Robots used by MX3D to build the steel bridge in the Netherlands are great examples of Scara 3D Printers.
The four types of FDM 3D printers are effectively used as per their applications. While the Cartesian 3D printer remains the dominant type of FDM 3D printer, other types like Polar and SCARA are quickly gaining an audience and finding new applications. It seems all the types of FDM 3D printers will have their niche market and usage.
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