3D-printing or additive manufacturing is a process of making objects from a digital file. In an additive process, as opposed to the traditional subtractive manufacturing, an object is created by laying down successive layers of material until the object is formed. There are several technologies that can be used to 3D-print an object, differing mainly in the way layers are built to create an object. Some methods use melting or softening material to extrude layers and others cure or fuse a photo-reactive resin, or a powder material with a UV laser (or another similar light source) layer by layer.1)
For the 3D-fagottini research project, two techniques were used to 3D-print different parts of the instruments: Stereolithography (SLA) technique for the metal keys, and Selective Laser Sintering (SLS) for the wooden part of the instruments, where in this case each bassoon joint was printed separately.
The method chosen to build the metal keys for the fagottini is based on a 3D-printed designed mould of the keys printed using Stereolithography (SLA) technique, which was then used to create keys in brass. The process is described in the tab 3D–CT scan.
Selective Laser Sintering (SLS) uses a beam of high intensity light, such as a laser, to fuse a powdered material–nylon by scanning the cross-sections, or layers generated by the 3D-modelling program on the surface of a powder bed. The objects created by this technique are both extremely high resolution, as low as 10 microns per layer, and also very strong. It was possible, for instance, to recreate the (originally metal) saddles in nylon attached to the body of the FT40 fagottino, instead of separately out of metal, as on the original instruments. These new 3D-printed parts in nylon are strong enough to support the resistance that the keys, together with the springs, offer while playing the instrument.
The SLS technology used to print the body of the fagottini was chosen because it is appropriate for creating precision objects that need to be both strong and durable, such as musical instruments.
1) Information about 3D-printing was taken from https://3dprinting.com/what-is-3d-printing/