3D Printer Extruder: A Simplified Guide to Understanding Direct and Bowden Extruder

When we choose a 3D printer, we often face a choice, direct extruder or Bowden extruder. So, what is a 3D printer extruder? And how 3D printer extruder affects the printing process. We are now discussing the extruder. First of all, the extruder is an important part of 3D printer. It is responsible for pushing out the material and feeding it into the hot end. Whether the transmission of the filament is accurate will directly affect the printing accuracy, etc. Secondly, different extruders have different advantages and corresponding disadvantages, understanding these two technologies will facilitate us to choose the right extruder and help the printer achieve better printing results.


What is an Extruder on a 3D Printer?

FDM 3D printer work by heating and melting thermoplastic materials (filament), and then depositing the material layer by layer to complete the construction of a 3D digital model. The 3D printer extruder play an important role in this process. There are two common extrusion systems are: direct extruder and Bowden extruder, which will also be referred to as direct and remote extruder. The extruder module is responsible for feeding the filament into a hot metal block with nozzle. The heated material is extruded through the nozzle, and cooled again to be deposited on the print bed for layer-by-layer accumulation.

The extruder needs to consider compatible materials, and some flexible materials require better performance of the printer. Of course, more consideration should be given to the basic use of the extruder, the extrusion force and the precise control of the material. Greater conveying force means high-efficiency printing, and reducing vibration during filament transmission can better ensure printing quality and precision.


Choosing the Right Extruder for Your 3D Printer: Direct vs Bowden

Different designs of extruders also have an impact on 3D printers. Understanding the features and limitations associated with the two commonly used extruders can help us choose the right printer and its configuration. The main difference between direct extruders and Bowden extruders is the location of the extruder and print head. The direct extruder is mounted inside the print head, while the Bowden extruder is mounted on the frame of 3D printer and connected by a tube to the hot end.

Direct Extruder: Suitable for Entry-Level 3D Printer

The direct extruder is one of the common extruder designs used for 3D printing. The direct extruder is mounted on the print head and can push the filament to the heating module, which is then extruded by the nozzle. The melted filament is deposited on the heating bed layer by layer to complete the construction of the model. The advantage of the direct extruder is that it is easy to maintain and easy to clean. If there is a problem with clearing or clogging of filaments, it will be easier to fix. However, the motor of the direct extruder is mounted on the print head, which increases the weight of the print head and can be a limitation for movement and stability during the printing process, resulting in less accurate print quality.


For entry-level desktop FDM printers, direct extruders are the most commonly selected and assembled. For example, the very popular beginner-friendly printer, Anycubic Kobra, is equipped with an integrated direct extruder, which provides greater delivery force and stable filament control, reduces filament transport jitter, and is compatible with a wide range of print materials including PLA / ABS / PETG / TPU. Anycubic Kobra is inexpensive and easy to use, also has an auto-leveling feature, making it ideal for cost-effective printer.


Bowden Extruder: High-Quality, High-Speed Printing

The Bowden extruder is also called a separate extruder. The extruder and the print head are installed separately. The extruder is responsible for advancing the filament and is connected to the print head through a tube. Obviously, the print head is lighter than a direct extruder, which will reduce the constraints on the print head and enable faster and more accurate printing. The Bowden extruder also has disadvantages, it uses a tube to advance the filament, is very easy to be clogged, users often encounter cleaning problems, and it is more difficult to maintain. Overall, Bowden extruders are the 3D extruder of choice for many larger and more advanced printer configurations.


Bowden extruders can be configured on large-size printers and achieve high-efficiency printing. One of the best large format printers, Anycubic Kobra Plus, has a print size of 300*300*350 mm. The printer is equipped with a Bowden extruder and a double-threaded z-axis moving structure, which can maximize stability to provide high-speed printing and achieve more model details. The extruder with all-metal gears is able to heat and melt the material quickly, and is equipped with a dual fan system for better smooth printing. Anycubic Kobra Plus is an upgraded version in terms of print size and quality. Preferential prices are available on the Anycubic official website, making it a superior choice among large-size printers.