The filament cutter uses an unusual (but effective) 3D printed spring design
When one needs a spring, a 3D printed version might not be the first choice. It might even be fair to say that printed springs are something unique end manufacture, rather than something that one proposes to use. This might change once you try the spring design in [the_ress]3D printed filament cutter with printed springs.
The filament cutter works like this: the filament is inserted into the device through one of the pairs of holes at the bottom. To cut the thread, press the plunger. This pushes a blade down to cleanly cut the filament at an angle. The cutter is the only unprinted part of the device; a single segment of an 18mm utility knife blade.
The sources are of particular interest and don’t quite look like a typical source. They take their design from this conformal linear motion mechanism documented on reprap.org and look like small 4-bar parallel linkages. These springs have limited travel, but are definitely springy enough for the job they need to do, and that’s the important part.
Want a more traditional coil spring? Annealing filament wrapped around a mandrel can yield useful results, and don’t forget the fantastic mechanisms known as flexes; they have obvious similarities with springs [the_ress] used. You can see its design in action in the short video, embedded below.