When it comes to innovation in FDM 3D printing, there doesn’t seem to be much room to move the needle. Pretty much everything related to filament printing has been stripped down to practicality, with more or less every assembly available on the market. Even the business end, the extruder, is so optimized that there isn’t much room left for innovation.
Or is there? The way [David Leitner] you see, there is, which is why you built this rolling screw extruder (if you can get to the Thingiverse link, [David] posted on reddit too). Standard extruders work on the pinch-roll principle, in which the relatively soft filament is fed through a spring-loaded gear connected to a stepper motor. The stepper turns the gear, which advances or retracts the hot end filament. [David]Instead, the design uses a trio of threaded rods mounted between two rings. The rods are angled to the central axis of the rings, forming a passageway that is just the right size for the filament to fit. When the rings rotate, the threads of the rods catch with the filament, gripping it in its entirety. circumference and forward or backward depending on which direction it is turning. The following video shows it working; we have to admit that it is quite fascinating to watch.
[David] he himself admits that it doesn’t have many advantages, perhaps apart from a reduced tendency to jump since the force is distributed over the entire surface of the filament rather than just a small pinch point. Regardless, we like the kind of thinking that goes into something like this, and we’re betting it probably has hidden benefits. And maybe the extruder really is a place for innovation after all; Witness this modular nozzle swapping system.
thanks again to [BaldPower] by the tip