For those just getting started with 3D printing, looking at the dazzling array of 3D printers on the market can definitely be a headache. Unlike traditional home appliances, which are generally consistent in appearance, 3D printers come in a variety of different structural types. Different structures have different advantages. Below, 3D Private School will provide a detailed overview of the current types of desktop printers.
Prusa i3 Structure
The Prusa i3 is the third generation model of the Reprap printer prusa mendel. Reprap was originally a type of 3D printer designed and built by Adrian Bowyer and others at the Department of Mechanical Engineering, the University of Bath in the UK. After the printer was unveiled, the designers open-sourced the relevant Reprap programs and structural designs to the public. Any enthusiast can find related printer design information, and even the program's source code, on their website. Due to Reprap's openness, it has become one of the easiest machine types for 3D printing beginners to learn. Through model upgrades and evolution, it has developed into the current Prusa i3. Its simple structural design and relatively low cost make the i3 the preferred choice for novice DIY printer enthusiasts.
The most prominent feature of the i3 is its minimalist frame structure. Its overall small footprint meets the requirements of a desktop machine. It has low requirements for assembly part precision, making it suitable for novice assembly. The main body is a rectangular gantry frame responsible for the movement of the print head in the Z and Y axis directions. Another part is the print platform, which is also responsible for movement in the X axis direction. Structurally, because the print platform needs to move in the X axis direction, this makes the model more prone to detaching during printing and also affects its printing speed.
Advantages:
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Simple structure, easy to learn, suitable for DIY enthusiasts new to 3D printing.
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Open design facilitates hardware upgrades or repairs and maintenance.
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Dual Z-axis motor design makes print head movement more stable.
Disadvantages:
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Low assembly precision of the frame structure leads to relatively low print accuracy.
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Print platform moves along the Y axis, increasing the risk of model shifting.
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Slower printing speed.
Box Frame Structure
The box frame structure, represented by MakerBot and Ultimaker, is currently the more popular structure on the market. Compared to general DIY models, it appears more commercialized in appearance. Printer movement is driven by motors and timing belts to move the print head along the X and Y axes. Unlike the i3 structure, the print platform only needs to move up and down along the Z axis via a lead screw motor. Precisely because the print head can move along the X and Y axes, the build volume can be utilized to its maximum. Therefore, industrial-grade 3D printers needing to print large models often choose this structure. The relatively enclosed build space of the box frame also leads some 3D printers focusing on ABS filament to choose this structure to isolate odors. This also leaves more room for creative exterior design. For example, domestic brands like Flashforge and Jgaurora have 3D printer designs that meet the aesthetic requirements of modern home appliances.
The box frame structure has several branches based on print head movement.
Ultimaker: The method of fixing the print head on cross rods makes printing more stable, indirectly improving printing precision and speed.
MakerBot: Two motors control the movement of the print head in two axes via timing belts. Unlike Ultimaker, the smooth rods guiding the print head movement do not cross.
Hbot: A timing belt transmission structure that has recently started gaining popularity. Unlike UM and MB where a single motor controls a single direction, its main operation mode involves the coordinated action of X and Y motors to move the print head in various directions. Because the routing of the motor timing belts forms an "H" shape, it is named Hbot.
Corexy: A structure improved from Hbot, also using coordinated action of X and Y motors. The difference is that Corexy has multiple timing belt routing methods.
Advantages:
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High molding precision.
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Fast printing speed.
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Circuit boards, power supplies, and other electronic components can be hidden inside the body, offering high space utilization.
Disadvantages:
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Relatively complex structure, not easy to assemble, troublesome to repair.
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High precision requirements for parts, leading to higher overall machine cost.
Delta / Delta-style Robots
This is a very common structure on the market, technically named the parallel arm structure. This structure was originally designed for machine claws capable of quickly and accurately grasping small, lightweight objects. Robots using this structure are now called parallel robots. This structure emerged in the 1990s, and due to its advantages of speed, precision, and high flexibility, parallel robots have become an important part of modern industrial robotics.
When applied to 3D printers, the parallel arm structure becomes what we commonly call the Delta or Delta-style model. The motion structure of Delta printers can be divided into two types. One is the motion mechanism represented by the most common printers on the market, the Rostock and Kossel. The other is the parallel mechanical arm structure. The former leans more towards practical application, while research on the latter focuses more on theoretical data analysis. Today, we will mainly discuss the Rostock/Kossel models.
Compared to other structural types, Delta printers have a smaller footprint and a relatively simpler structure. In terms of model size, Deltas can print taller models. Due to their structure, they have faster printing speeds and higher transmission efficiency. The disadvantages of Delta printers are also linked to their parallel arm structure. Although the footprint is small, the printer needs space for the three parallel arms to move, which directly limits the utilization of the build volume. Additionally, because they use a special interpolation algorithm for coordinate positioning, structures like arcs can only be approximated using multiple straight line segments, leading to slightly lower precision.
Advantages:
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Simple structure, convenient for repair and maintenance.
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Fast printing speed, high transmission efficiency.
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Small footprint.
Disadvantages:
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Low build volume utilization.
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Because the print platform is fixed, leveling and debugging the printer is relatively complex and not suitable for beginners.
Other Models:
Printbot
Printbot is also a branch of the Reprap printer family, structurally very similar to the Prusa i3 but missing one Z-axis support. The Printbot claims to be the world's simplest and cheapest printer. Its original design intention was to create a 3D printer that even children could assemble and repair, while also allowing more students to access 3D printing at a lower cost. Therefore, its biggest feature is its extremely simple structure. In terms of price, it is also significantly cheaper than mainstream MakerBot and Ultimaker printers. However, its drawbacks are also quite prominent: the model build size is small, and as a teaching machine, its printing precision is average. But for DIY enthusiasts just getting into 3D printing, it is still a good choice.
Robotic Arm 3D Printers
These are 3D printers modified or designed based on traditional multi-axis robotic arms. Besides 3D printing, these robotic arms typically also have other functions like laser engraving and object grasping. A very typical domestic example of such a robotic arm supporting 3D printing is Dobot.
