Comments on our Bowden vs Direct 3D printer extruder post led us to the “flying extruder” concept, which is a bit of both.
As we described in the previous story, the two primary methods of plastic filament extrusion used in desktop 3D printers today are “Direct”, where the filament is pushed directly into the hot end from a motor mounted on top of the hot end, or the “Bowden” concept, where the motor is remotely located and must push the filament through a long tube to reach the hot end. There are advantages and disadvantages of both approaches.
While those are the most frequently found methods, there are many other less seen alternatives, and even more experimental ones. All attempt to overcome the disadvantages of the approaches.
One of those experiments is a radical idea called the “Flying Extruder”, and they’re not kidding. Designed by folks on the RepRap forum a few years ago, the design attempts to do the following:
- Remove weight from the moving portion of the printer, making momentum shifts much easier
- Remain “close” to the hot end to enable effective printing of flexible materials and remove tube friction
- Reduce motion “lag” caused by lengthy tube traversals
Apparently, the approach works, although the resulting motion of the hot end and flying extruder look a bit suspicious, as you can see in this video:
The images above are the original prototype. We wondered whether such a design could endure many prints, as is quite a bit of motion that may cause things to wear out, such as the rubber bands holding up the extruder. They’ve been replaced with a counterweight system as shown here.
While there are many experiments such as this one, few make it to market as many designs prove impractical for manufacturing, pricing or endurance. But this one has!
You can purchase a DeltaWASP 20 40 3D printer that includes the flying extruder approach (which they call the “amortized bowden”) for €2,370 (USD$2,550). This machine is a delta, which typically use a full Bowden extruder. Such machines often have trouble printing flexible filament, but not so with the DeltaWASP 20 40.
And if you’d like to make one on your own, there is a design for a flying extruder available for free download at Thingiverse.