3D printed Titanium Difference tone bell
- Australian Bell
- Longnow Foundation
- CSIRO Lab 22
Invited by Danny Hillis of the Longnow Foundation to invent a difference-tone bell design suitable for the Longnow Foundation’s 10,000-Year Clock project inside a mountain in Texas (www.longnow.org) and subsequently, commissioned to cast and tune a musical set of ten difference tone bells to a musical scale composed by Brian Eno for the Clock, I decided to use this unique Finite Element Analysis (collaborator Ryan Adams) bell design in a Synapse Residency at CSIRO’s Lab 22 with its director Dr Daniel East. Currently on exhibition at the Grainger Museum is the world’s first 3D printed in Titanium difference-tone bell.
After co-inventing the Harmonic bell design used in the Federation Bells Carillon in Melbourne, I have been inventing new sounds from new bell designs. The opportunity to work with Dr Daniel East at CSIRO Lab 22 on 3D printing in direct metals titanium and stainless steel allowed for the printing of difference tone bells. Our paper on the acoustic research of 3D printed metal bells has been accepted for publication by MIT\’s Leonardo Journal. My work in bell design offers new opportunities for placing bells in contemporary urban design as place-making and way-faring ambient sound overlay in the built ecology.
Difficult to see the impact of so recent a technological innovation, but it will become the future of new bell design, and open up new uses for bell sound experience, as music, as acoustic spatial mapping in the built environment and as sound for personal wellbeing use. As the cost of 3D printing technology falls and its scale of production rises even traditional church uses of the bell will surely be replace with 3D printed bells.
The bell is a profound cultural artefact that has subliminal resonance in most civilisations. Its transition from the occult \’Voice of God\’ to an instrument of music, and the two distinct traditions developed in Europe and Asia, have seen bell design invented by iteration over centuries. The digital revolution has opened up new design possibilities for new sound experiences, and my work has been at the forefront of this invention. The request to invent a difference tone bell was based on the need for a bell at half the scale of any there bell for a given pitch, if the low pitches of the Clock\’s bell could fit the space. Post this project, 3D printing this bell design is a world first.
3D printing of bells is the future for bell making. Virtual Finite Element modelling of complex vibrational forms for new acoustic experience pushes beyond the capacity of cast molten metal and moulds. Virtual models of highly complex forms can be 3D printed in stainless steel, titanium. The swirl of liquid metal in moulds and differential cooling produces density disparity in the casting. 3D printing with laser beams produce constant density, critical for musical performance of the bell. This innovation points to the future of bell design and fabrication.
A difference tone bell has the unusual feature of sounding a pitch an octave below its fundamental or lowest frequency. Most bell\’s pitch are their fundamental frequency. The difference tone bell produces a psychoacoustic pitch sensation in the listener\’s ear. This acoustic phenomenon means that this FEA bell design need only be half the scale of any other bell sounding the same pitch.