If you are advanced in building or renovating 3D printers, you will soon find yourself improving your 3D printer extruder. But what choices can and should you make when designing it? We look at the possibilities, the choices and the common mistakes that are made.
What types of 3D printer extruder are there?
Before we can look at what a 3D printer extruder consists of in terms of components, it is good to know that there are roughly two choices when choosing a 3D printer extruder, namely bowden or direct drive setups. There is no right or wrong here, they both have advantages and disadvantages. The result is also the same, melting the 3D printer filament to start 3D printing, but the position of some components is different. Let's take a closer look at both.
Bowden 3D printer extruder
As can be seen in the image above, with a Bowden 3D printer extruder the extruder motor is not mounted at the hotend, but elsewhere on the frame. A PTFE tube will be mounted between the motor and the hotend, which guides the filament to where it should go. A Bowden 3D printer extruder has advantages and disadvantages, namely:
Advantages:
- Better and faster 3D prints ; the hotend combination has less weight to move and can therefore move faster, both in acceleration and absolute speeds. This ensures better quality 3D prints that are also often quieter.
- Larger print volume; is not always the case, but often the hotend can be made smaller, resulting in a larger print volume. Manufacturers of 3D printers often know how to deal with this effectively, so you will not often see this difference.
Cons:
- More trouble with stringing; the extruder motor is mounted elsewhere and has some delay because a distance has to be bridged, which can result in some more post-processing in the 3D prints made.
- More difficult to print flexible 3D printer filament; It can happen that flexible 3D printer filament gets stuck in the PTFE tube between the extruder motor and the hotend. Because it is soft material, it can get into places where you would rather not have it.
- More powerful 3D printer extruder motor needed ; Because it has to push more material, this motor often needs to be larger than 3D printer extruder motors on direct drive setups. This is often not a problem, but it does require more power.
Direct drive 3D printer extruder
A direct drive 3D printer extruder has the extruder motor mounted directly on the moving hot end, as shown in the image above. This motor is often mounted as close as possible to the nozzle to keep the distances small. What advantages and disadvantages does this setup have?
Advantages:
- More 3D printer filaments to print; Due to the short distance between the extruder motor and the hotend, flexibles and other softer materials can be printed without problems, often with more reliability and without experiencing stringing.
- More reliable 3D prints; Because there is less that can go wrong in the PTFE tube between the motor and the hotend due to the distance, you generally also get a more reliable 3D printer.
- Smaller 3D printer extruder motor required; Because the distance to be bridged is smaller than with a Bowden setup, the 3D printer extruder motor can often be made smaller, resulting in less power in the 3D printer.
Cons:
- More maintenance; Because the entire hotend is often full and is built quite close together, it requires more frequent maintenance. It is less easily accessible, so it can be a bit more work
- Lower 3D printer speeds; Because the hotend has become heavier, slower speeds can be achieved than on a Bowden 3D printer extruder. More vibrations and noise are often the result of this.
What 3D printer extruder types are there?
There are various 3D printer extruders, the most important are:
- Direct drive 3D printer extruder
- Bowden 3D printer extruder
- Combinations of the above