Rotary Extruder
Traditional Fused Filament Fabrication (FFF) extruders feed the filament into the melt zone with 1 or 2 drive gears, thereby only providing 1-2 points of contact between the drive system and the filament. At higher speeds or extrusion forces this can result in slipping and subsequent under-extrusion. The rotary extruder consists of 3 drive rollers each offering multiple points of contact, significantly increasing engagement between the drive mechanism and the filament.
This is particularly beneficial for 3D printing with metal powder based filaments. These filaments are more fragile due to their high metal powder and low binder content, and the distributed contact of the rotary extruder minimizes the risk of filament failure. In addition, the non-slip characteristic of the extruder eliminates under-extrusion, resulting in high solidity, which is especially desirable in metal parts.
Higher reliability
The multi-contact rotary extruder transfers the extrusion force over an increased number of contact points, reducing filament stress and minimizing the risk of filament failure.
Higher speed
Output efficiency of rotary extruder vs convention extruder, the rotary extruder delivered 100% of requested flow up to filament tensile strength limit
Higher printing speeds require higher extrusion forces. Our testing has demonstrated that extruder slip under high speed- high force conditions has been eliminated, removing extruder performance as a system limitation.
Fused Filament Fabrication
Fused Filament Fabrication (FFF) is an additive manufacturing process by which raw material in the form of filament wound on a spool is fed through a hot-end by means of an extruder mechanism. In the hot-end, the material is melted and pushed through a nozzle which deposits it in layers to build a part.
FFF is complimentary to other additive manufacturing processes with each having their strengths. FFF is typically characterized by a lower system cost, ease and safety of material handling, and the ability to create fully enclosed hollow features not possible with resin or powder based processes.
The latter can be particularly interesting as 3D printing offers the ability to design and manufacture lightweight hollow parts with internal stiffening features.
Traditional Fused Filament Fabrication (FFF) extruders feed the filament into the melt zone with 1 or 2 drive gears, thereby only providing 1-2 points of contact between the drive system and the filament. At higher speeds or extrusion forces this can result in slipping and subsequent under-extrusion. FuseLab’s rotary extruder consists of 3 drive rollers each offering multiple points of contact, significantly increasing engagement between the drive mechanism and the filament. This resolves one of the constraints of traditional FFF systems.
The benefit is pronounced when 3D printing with metal or ceramic powder based filaments. These filaments are more fragile due to their high powder and low binder content, and the distributed contact of the rotary extruder minimizes the risk of filament failure. In addition, the non-slip characteristic of the extruder eliminates under-extrusion, resulting in high solidity, which is especially desirable in metal parts.
Layer consistency
X-ray density test part produced on the FL300M. The characteristic layers of the FFF process are clearly visible under the microscope.
For FFF processes utilizing bound powder filaments, the printed part is called the green part and is subsequently processed through the debinder, removing the majority of the binder, yielding the brown part. The brown part is then sintered in a sintering oven to remove the remainder of the binder and fuse the metal or ceramic powder to form the final solid part.