[3D Printing Knowledge] Easy-to-understand Illustrated Guide! Two Feeding Principles of 3D Printers and Their Impact

[3D Printing Knowledge] Easy-to-understand Illustrated Guide! Two Feeding Principles of 3D Printers and Their Impact

There are countless 3D printers , with a plethora of technical terms. You may have heard of two designs: Direct Drive Extruder and Bowden Extruder, but what exactly do they refer to? How do they affect the printing results? And which one should you choose? Let us explain based on the principles!

Basic principles:



The image on the right shows a direct drive type. Since the printhead itself has a propeller, the wire is directly pushed into the heated nozzle. This also means that when the printhead moves along the x-axis, it must bear the weight and vibration of the propeller.

The image on the left shows a tubular delivery system, typically with a pusher mounted on the frame of the 3D printer , separate from the print head; this is why the filament requires an additional delivery tube, a feature clearly visible on the Ultimaker . By feeding the filament to the nozzle through the delivery tube (usually made of PTFE plastic), the filament is prevented from being affected by clipping or the pulling of the machine's operation.



What are the advantages and disadvantages of these two forms?

• Using direct drive:

Advantages: Material replacement is direct and convenient, cleaning is relatively quick, it is usually highly mobile, and it is generally suitable for modification enthusiasts.


( The Lulzbot Mini 2 3D printer, featuring direct drive, is portable with a carrying handle. )

Disadvantages: Due to the influence of the propulsion system, a large amount of horsepower is required for printing; also, due to the vibration of the print head and the large amount of directional forces, the accuracy and stability of the printing are relatively limited.


( The printhead of the Lulzbot Mini 2 3D printer , which is directly driven, must bear the weight of the propeller and physical influences during printing. )

• Use delivery pipelines:

Advantages: Since the weight of the propeller is not on the print head, high-speed printing can be achieved with less horsepower; 3D printers can move slightly with lower acceleration, which reduces vibration caused by changes in position, resulting in more accurate printing results and improved overall layer consistency.


(The image shows the nozzles inside a 3D printing printhead with a pipeline delivery system . Because it does not have a propulsion unit, it has a lower load. )

Disadvantages: Due to the long distance between the pipeline and the propeller and nozzle, the flexible wire may bend significantly during input, making the delivery less smooth. Slight timing errors during wire extension and retraction may occasionally cause fraying when printing suspended structures.
Fortunately , these issues can now be resolved by increasing the retraction distance and speed parameters; in the latest version of Ultimaker , Cura 3.6 , this can be easily achieved using the manufacturer's original materials and parameter settings . (Further reading: Automatic setting for special cables with Ultimaker Cura 3.6! )

Additionally, using the Ultimaker S5 as an example, there are two extra steps involved in daily cleaning :

1. Push open the white clip



2. Pull out the tubing



Neither of these two methods is inherently superior or inferior; it depends on individual user needs. Besides the factors mentioned above, the quality of a 3D printer also depends on many other factors, and the best 3D printers should be able to handle various situations. If you're still feeling overwhelmed, please refer to the key points below.

The Lazy Person's Comparison Method:

For those who require high printing speed and precision, and do not mind multiple cleaning steps, a pipeline conveyor 3D printer can be selected.
If you don't care about printing speed and want to modify it yourself or move it frequently , you can choose a direct drive 3D printer .

Want to learn more about 3D printing technology? Want to experience how a 3D printer works? Want to personally verify the precision of the Ultimaker S5 ? We will be holding a 3D printing workshop after the New Year, where you can also see various samples. Don't miss this great opportunity! Register online now ! Seats are limited, first come, first served!

Reference: https://all3dp.com/2/bowden-tube-all-you-need-to-know/