There are hundreds of 3D printers, with a lot of jargon. In terms of type, 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 the principles!
．Basic Principles:
The image on the right shows a direct drive type. Since the print head itself has an extruder, the filament is directly pushed 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 extruder.
The image on the left shows a Bowden tube system. The extruder is usually installed on the frame of the 3D printer and is separate from the print head. This is also why the filament needs an additional Bowden tube for conveyance, a device clearly visible on Ultimaker. By conveying the filament through the Bowden tube (usually made of PTFE plastic) to the nozzle, the filament can be prevented from being affected by kinks or pulls from machine operation.
What are the advantages and disadvantages of these two forms?
．Using Direct Drive:
．Advantages: Direct and convenient filament changes, faster cleaning, usually more mobile, generally suitable for modders.
(The direct-drive Lulzbot Mini 2 3D printer has a handle for portability.)
．Disadvantages: Limited by the extruder, it requires more motor power for printing; also, due to more vibrations and directional forces on the print head, the printing precision and stability are more limited.
(The print head of the direct-drive Lulzbot Mini 2 3D printer must bear the weight and physical effects of the extruder during printing.)
．Using a Bowden Tube System:
．Advantages: Since the weight of the extruder is not on the print head, high-speed printing can be achieved with less motor power; the 3D printer can move slightly with lower acceleration, which reduces vibrations caused by changing positions, resulting in more accurate prints and improved overall layer consistency.
(The image shows the nozzle exposed inside a Bowden tube system 3D print head. Since there is no extruder installed, the burden is lighter.)
．Disadvantages: Due to the longer distance between the tube, the extruder, and the print head, flexible filaments may not feed as smoothly due to larger bending angles during input. There may be a slight time lag between filament extrusion and retraction, sometimes causing stringing when printing suspended structures.
Fortunately, these issues can now be resolved by increasing retraction distance and speed parameters. In the latest version of Cura 3.6 for Ultimaker, you can easily set this using the original soft filament and parameter settings. (Further reading:Automatic settings for special filaments with Ultimaker Cura 3.6!)
In addition, taking the Ultimaker S5 as an example, there are two extra steps for daily cleaning:
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 feeling confused, you can refer to the key points below.
．Comparison for the lazy:
．If you require printing speed and product precision, and don't mind a few extra steps for cleaning, you can choose a Bowden tube system 3D printer.
．If you don't mind the 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? After the New Year, we will be holding 3D printing lectures, where you can also see various samples. Don't miss this great opportunity! Click here to register online! Seats are limited, so register before it's full!
References: https://all3dp.com/2/bowden-tube-all-you-need-to-know/