Fabulous Fandrich re-Fabrication - 04/01/13 01:24 PM
As many of you are aware, Mr. Del Fandrich is one of the most innovative piano designers and technicians who is practicing today. Earlier this morning, he announced a breakthrough in piano technology. I reprint it here in full.
"I’ve been installing Wessel, Nickel & Gross action parts for some time now. I consider them to be a significant step forward in the ongoing developing development of the piano action. In particular I like the hammer shanks and I have now discovered a heretofore unknown benefit—the hammershanks themselves can be “voiced†to enhance the tone performance of the piano.
The thought occurred to me, as I was gluing hammers to the Wessel, Nickel & Gross carbon fiber shanks, that what we have here is a finite cylindrical pipe. In other words, the hammershank itself forms a cylinder with a fixed internal diameter and a finite length. When a flow of air is passed over the open end of a finite cylindrical pipe—i.e., as when a note is played and the hammer is accelerating toward the strings—it causes the air within the pipe to resonate at a pitch determined by the diameter and the length of the cylinder and this pitch is, to some extent, tunable.
The internal diameter of these hammershanks is fixed but we can still change their resonant frequency by changing the length of the pipe and this can be done by partially filling it with some rigid material such as epoxy. This has to be done carefully to get just the right pitch in the resonating pipe. (A good overview on the character of finite cylindrical pipes and calculating their pitch is given in The Physics of Musical Instruments by Fletcher & Rossing.) The principle here is to match the pitch of these resonating pipes to the frequency of one of the resonating partials in the strings. (As supplied by Wessel, Nickel & Gross their pitch does not reinforce the pitch of the notes played and, indeed, may detract from it.) These resonating pipes are tunable to a certain extent by trial and error; if you put just a bit too much epoxy into the hollow hammershank and get its pitch a little high you can always drill it out—albeit with some difficulty—to lower the pitch of the generated tone.
The volume of the tone generated by the resonating column of air in the hammershank/pipe is directly proportional to the velocity of the hammershank hence it is advantageous to keep the mass of the hammers low and, by extension, their potential velocity high. It is fortuitous that the volume of the tone generated by a moving finite cylindrical pipes is relatively low at pianissimo velocities and somewhat louder at forte levels of play thus the tone generated by the moving pipes appropriately and automatically reinforces the tone created by the hammers and strings across the power spectrum of the piano.
Obviously my work to date with Resonant Hammershank Voicing is in its early stages and has, thus far, only scratched the surface; much work remains to be done before we can exploit the full potential of this new technology. There are at least two areas that have already revealed a need for more research: 1) Shank protrusion, by allowing the hammershank to protrude slightly beyond the hammer molding seems to reduce the air turbulence immediately adjacent to the hammer molding making the tone generated by the resonant pipe clearer and stronger, and 2) Hammer shape, the shape of the hammer affects the flow of air around the felted portion of the hammer and this can affect the flow of air past the opening in the resonant pipe (if the airflow is not clean and smooth a certain amount of “falseness†can be detected in the resonant tone).
As well, new shapes for the hammershanks themselves should be explored to better match the tone generated by the resonant pipes to the natural voice of the piano. If the weight of the carbon fiber hammershanks can be kept low enough, for example, it would be interesting to explore hammershank shapes approaching that of a true Helmholtz resonator. Since it is often claimed—albeit probably incorrectly—that Helmholtz influenced the design of the early Steinway pianos this would finally bring the relationship between Helmholtz and the piano full circle."
It seems to me that if this creative approach were combined with Mr. Bill Bremmer's "Pipe Organ Effect," the perfect piano might finally be a reality.
"I’ve been installing Wessel, Nickel & Gross action parts for some time now. I consider them to be a significant step forward in the ongoing developing development of the piano action. In particular I like the hammer shanks and I have now discovered a heretofore unknown benefit—the hammershanks themselves can be “voiced†to enhance the tone performance of the piano.
The thought occurred to me, as I was gluing hammers to the Wessel, Nickel & Gross carbon fiber shanks, that what we have here is a finite cylindrical pipe. In other words, the hammershank itself forms a cylinder with a fixed internal diameter and a finite length. When a flow of air is passed over the open end of a finite cylindrical pipe—i.e., as when a note is played and the hammer is accelerating toward the strings—it causes the air within the pipe to resonate at a pitch determined by the diameter and the length of the cylinder and this pitch is, to some extent, tunable.
The internal diameter of these hammershanks is fixed but we can still change their resonant frequency by changing the length of the pipe and this can be done by partially filling it with some rigid material such as epoxy. This has to be done carefully to get just the right pitch in the resonating pipe. (A good overview on the character of finite cylindrical pipes and calculating their pitch is given in The Physics of Musical Instruments by Fletcher & Rossing.) The principle here is to match the pitch of these resonating pipes to the frequency of one of the resonating partials in the strings. (As supplied by Wessel, Nickel & Gross their pitch does not reinforce the pitch of the notes played and, indeed, may detract from it.) These resonating pipes are tunable to a certain extent by trial and error; if you put just a bit too much epoxy into the hollow hammershank and get its pitch a little high you can always drill it out—albeit with some difficulty—to lower the pitch of the generated tone.
The volume of the tone generated by the resonating column of air in the hammershank/pipe is directly proportional to the velocity of the hammershank hence it is advantageous to keep the mass of the hammers low and, by extension, their potential velocity high. It is fortuitous that the volume of the tone generated by a moving finite cylindrical pipes is relatively low at pianissimo velocities and somewhat louder at forte levels of play thus the tone generated by the moving pipes appropriately and automatically reinforces the tone created by the hammers and strings across the power spectrum of the piano.
Obviously my work to date with Resonant Hammershank Voicing is in its early stages and has, thus far, only scratched the surface; much work remains to be done before we can exploit the full potential of this new technology. There are at least two areas that have already revealed a need for more research: 1) Shank protrusion, by allowing the hammershank to protrude slightly beyond the hammer molding seems to reduce the air turbulence immediately adjacent to the hammer molding making the tone generated by the resonant pipe clearer and stronger, and 2) Hammer shape, the shape of the hammer affects the flow of air around the felted portion of the hammer and this can affect the flow of air past the opening in the resonant pipe (if the airflow is not clean and smooth a certain amount of “falseness†can be detected in the resonant tone).
As well, new shapes for the hammershanks themselves should be explored to better match the tone generated by the resonant pipes to the natural voice of the piano. If the weight of the carbon fiber hammershanks can be kept low enough, for example, it would be interesting to explore hammershank shapes approaching that of a true Helmholtz resonator. Since it is often claimed—albeit probably incorrectly—that Helmholtz influenced the design of the early Steinway pianos this would finally bring the relationship between Helmholtz and the piano full circle."
It seems to me that if this creative approach were combined with Mr. Bill Bremmer's "Pipe Organ Effect," the perfect piano might finally be a reality.
