There are hundreds of types of 3D printers, and a lot of technical terms. In terms of design, you might have heard of two types: 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 their principles!
．Basic Principles:
The image on the right shows a direct drive system. Since the print head itself has a feeder, the filament is pushed directly into the heated nozzle. This also means that when the print head moves along the X-axis, it must bear the weight and vibration of the feeder.
The image on the left shows a Bowden tube system. The feeder is usually located on the frame of the 3D printer and is separate from the print head. This is why the filament needs an additional feed tube. This setup is clearly visible on Ultimaker printers. By feeding the filament through the tube (usually made of PTFE plastic) to the nozzle, the filament can be prevented from being affected by kinks or tugging from machine operation.
What are the advantages and disadvantages of these two forms?
．Using Direct Drive:
．Advantages: Easy and convenient filament changes, faster cleaning, usually more mobile, and generally suitable for users who like to modify their printers.
(The Lulzbot Mini 2 3D printer, which uses direct drive, has a handle for portability.)
．Disadvantages: Limited by the feeder, it requires more power for printing; also, due to more vibrations and forces in various directions on the print head, the printing precision and stability are more restricted.
(The print head of the direct drive Lulzbot Mini 2 3D printer bears the weight of the feeder and physical effects during printing.)
．Using a Bowden Tube:
．Advantages: Since the weight of the feeder is not on the print head, high-speed printing can be achieved with less power; the 3D printer can move slightly with lower acceleration, reducing vibrations caused by changing positions, resulting in more precise printing and improving overall layer consistency.
(The image shows the nozzle exposed inside a 3D printer print head with a Bowden tube system. Since there is no feeder loaded, the burden is lighter.)
．Disadvantages: Due to the longer distance between the tube and the feeder and print head, flexible filaments may not feed as smoothly due to larger bending. Since there is a slight time delay when extruding and retracting the filament, stringing may occasionally occur when printing unsupported structures.
Fortunately, this can now be resolved by increasing the retraction distance and speed parameters; in the latest version of Cura 3.6 for Ultimaker, using original soft materials and parameter settings makes it easy to configure. (Further reading:Automatic settings for special filaments in Ultimaker Cura 3.6!)
In addition, taking the Ultimaker S5 as an example, daily cleaning involves two extra steps:
1. Push open the white clip
2. Pull out the tube
There is no absolute superiority or inferiority between these two forms; it depends on your usage needs. In addition to the influences mentioned above, the quality of a 3D printer also depends on many other factors, and the best 3D printer should be able to overcome various situations. If you're still confused, you can refer to the key points below.
．Comparison for the impatient:
．If you prioritize printing speed and precision, and don't mind a few extra steps for cleaning, you can choose a Bowden tube 3D printer.
．If you are not concerned about printing speed and want to modify it yourself, or frequently move it, you can choose a direct drive 3D printer.
Want to learn more 3D printing techniques? Want to experience how a 3D printer works? Want to personally verify the precision of the Ultimaker S5? After the New Year, we will be holding 3D printinglectures, and you will also see various samples on the day. Don't miss this great opportunity, click here to register online! Seats are limited, so register now!
References: https://all3dp.com/2/bowden-tube-all-you-need-to-know/