There are two types of extruders found in most common desktop 3D printers today . Both the direct extruder and the Bowden extruder have some advantages and disadvantages that you should definitely know before buying or converting.
“Oldschool” direct extruder?
This is (still) the most common type of construction, especially when it comes to cheap DIY kits, you can almost exclusively find direct extruders. With the direct extruder, the stepper motor is placed directly on the hotend .
A big advantage is that all filament-processed components are in one place. However, if there are problems with printing, disassembly can be quite strenuous. A further disadvantage is the weight , so go right a few drawbacks associated:
- the power consumption is greater
- the wear on toothed belts and plain bearings is greater
- the printing speed is slower
With the direct extruder , the printhead often weighs 0.5kg ! Of course, this must be constantly accelerated and decelerated. That also creates vibrations. Printing speeds of more than 80mm / s are hardly possible. In the case of cheaper models with acrylic frames and poor assembly, only 50mm / s are often possible.
Nevertheless: I would always choose the direct extruder to get started if the price is significantly more attractive than models with a Bowden extruder. The print results are a little better, especially for beginners, as not so much has to be configured and the interaction of the many parameters (e.g. retraction speed, temperatures, Z-hops) is difficult to understand.
Bowden Extruder: The Better Way?
With the Bowden extruder, the stepper motor, which is responsible for feeding the filament, is not attached to the hotend, but (mostly) to the frame of the 3D printer .
Bowden extruder advantages include: the weight on the movable print head is significantly reduced . The Bowden extruder can often be found on Delta 3D printers, for example, as it is essential here to keep the weight of the print head as low as possible. But even with entry- level models , such as the Tronxy X3 , a Bowden extruder was installed next to the aluminum frame.
However, there are also disadvantages: for example, flexible filament can only be printed with difficulty or not at all, as it would compress in the tube. Another disadvantage is setting the correct retraction value. Even if the stepper no longer feeds the filament, the filament between the stepper and the hotend continues to push, which means that filament continues to be “printed” if the settings are poor. This usually leads to threads and protruding edges.
The most famous Bowden extruder is currently the E3D V6, which is available from GearBest for less than 10 €! Just make sure to choose the correct nozzle size (0.2mm or 0.4mm). If you decide to convert, you will find dozens of good mounts on Thingiverse, especially for Anet 3D printers .
Conclusion: choosing the right type of extruder
As is so often the case: there is no clear yes or no. But from us a crisp decision-making aid ;-). Are you a beginner and you don’t really care about speed, but want to learn and only print with PLA and ABS? Then take the direct extruder.
Do you already have experience? Do you know what most of the parameters in your slicer mean? Do you print a lot and want higher print speeds? Then opt for a 3D printer with a Bowden extruder or for a conversion.