•Acceleration of Music Rolls Whilst Playing Twice recently I have played the YouTube examples of player piano rolls; the latest was "The Ice Skaters" Fox Trot mentioned in MMD 31/01/17: https://www.youtube.com/watch?v=dGXZdY0-h18 In each case the music appeared to be playing considerably faster at t...

•Hi everyone. Well now, I have to take issue with those who say that the velocity of a hammer _cannot_ be increasing after its set-off. The function of the set-off is of course to reposition the hammer nose correctly in order to facilitate repetition; and to allow the hammer to fly freely before mak...

•The hammer is most certainly _not_ accelerating after the jack is disconnected from the hammer butt. _Any_ system that accelerates _must_ have energy put into it and the jack is the only energy input the hammer has. In fact, gravity is taking its toll the instant the jack stops imparting energy to ...

•Hi All, I'm not a physics anything but I do know this much: the hammers in an upright action pass over the center of balance point before they hit the strings. Anyone who has spaced hammers to the strings before the hammer return spring rail is installed knows this perfectly well. This is due to th...

•If I can remember back twenty odd (at least some were) years to my college Physics, a great deal of time was spent discussing force, velocity, and acceleration. As it was put simply to this Freshman, acceleration is a change in velocity and can only come about through a force applied to the subject...

•Hi folks, I guess it is humble pie time. I am tracing my family tree at present and have discovered that I am not related to Isaac Newton. A mental block is the only way that I can describe my thinking. Thanks to all who put me right. Roger Waring

•Jeff Davis suggested yesterday that "a very firm blow in a grand can make the hammer shank bend, or "whip", and that "it may be possible for the hammer to accelerate after let-off, as it unbends." A hammer shank, if bent, will have some energy stored. It will release that energy as it straightens o...

•In a message dated 98-05-08 Ray Fairfield writes: > The center of gravity of an object can only move if it is acted on > by an outside force .... Friends, the principles previously enumerated presume straight-line acceleration, which is incorrect. Piano hammers travel in an arc. While the hammer sh...

•Hi, Here is my view on the subject. Let us look at a ice skater turning around his own axis with arms stretched out sideways. He accelerates initially and the spins around at a certain speed. Compare his one arm being a hammer shank travelling. Now, if he pulls his arms in or bends them, he will sp...

•Bernt Damm wrote: > Some other point to note here is that the energy transmitted from > the hammer to the string is constant, flex or no flex of shank, > because the moving mass does not change. I therefore say that it > will not influence the volume of sound at all if the shank bends > a little or...

•Robbie, You wrote: > Although the center of mass (hence the inertia) might shift slightly > as you describe, I think the energy stored in the compliant shank > dominates the situation. Think of a limber golf club, or the > pole-vaulter with a fiberglass pole. Please don't think of a limber golf clu...

•Bernt Damm wrote: > Some other point to note here is that the energy transmitted from > the hammer to the string is constant, flex or no flex of shank, > because the moving mass does not change. I therefore say that it > will not influence the volume of sound at all if the shank bends > a little or...

•My previous posting was maybe little misunderstood by some readers. I wrote: > Some other point to note here is that the energy transmitted from > the hammer to the string is constant, flex or no flex of shank, > because the moving mass does not change. I therefore say that it > will not influence ...

•Since we have been discussing tempo acceleration of the music on rolls, I wanted to measure an Ampico roll and an 88-note roll of about the same length, and see if the steps-per-beat of the perforator at the beginning and end of the roll was changed. I first had to choose rolls that traditionally h...

•All: I couldn't find this in the archives, so I'm asking (probably again). 1. On a big core A-roll (or any other big core roll) what is the feet/minute tempo difference between the beginning and the end. 2. If known, what is the approximate difference from tune to tune, assuming the tunes are each ...

•Thanks Robbie. I've enclosed two documents -- an Excel spread sheet implementing your formula, and a text output of same. Cheers, George Bogatko gbogatko@intac.com http://www.intac.com/~gbogatko - - - Roll buildup effect on A-roll speed, assuming ten 2.5-minute tunes, evenly divided. Assume standar...

•Arrangements for 10-tune nickelodeon rolls must deal with the constantly increasing paper speed, as the paper builds up on the constant-speed take-up spool. This paper presents the mathematics involved. Units: distance: inches time: seconds Parameters: p = paper thickness (inches) r0 = initial radi...

•Re: Digest 980425 I have been waiting to respond to the ongoing discussion about "build-up" in roll speed, but now that Robbie has done all the work of posting his formulae, my post can be easy. In 1984, Robbie assisted the Chicago Chapter of AMICA in producing NEW Ampico rolls. Robbie's part was t...

•Several people have asked me over the past few weeks how the tempos were chosen for the new Telarc CD of Rachmaninoff's Ampico rolls. Tempo is extremely important, of course, so I thought it would be worthwhile to write a short article to be included with the liner notes in the upcoming Telarc CD e...

•Julian Dyer was wondering about roll acceleration in Ampico rolls. He was wondering why Ampico didn't correct it, etc. when Duo-Art did. The "acceleration" Wayne Stahnke was referring to is caused by all air motors' loading characteristics. There was never an air motor built that doesn't slow down ...