Half a croissant, on a plate, with a sign in front of it saying '50c'
h a l f b a k e r y
Now, More Pleasing Odor!

idea: add, search, annotate, link, view, overview, recent, by name, random

meta: news, help, about, links, report a problem

account: browse anonymously, or get an account and write.

user:
pass:
register,


                                                       

Hoop Piano String

More compact, needs no tuning
  (+2)
(+2)
  [vote for,
against]

A piano "string" which is actually just a metal hoop. No tension need be added because the structure of the "hooped string" is such that it will vibrate like a bell when struck thus remaining permanently tuned.

The different sizes could be lined up inside the piano concentrically and played by the same hammer/damping mechanism of a regular piano.

Optional: You could have the hammers located at the harmonic points so you could partially dampen the strings to get a neat effect. You'd have to stagger the locations of the hammer/damper mechanisms anyway so this could be kind of cool.

doctorremulac3, Dec 04 2013

In-plane vibrations of annular rings http://imechanica.o...eVibrations1976.pdf
The vibrational modes of rings are inharmonic. [spidermother, Dec 05 2013]

Toy piano http://en.wikipedia.org/wiki/Toy_piano
[pocmloc, Dec 05 2013]

[link]






       This is a baby step away from a glockenspiel, which I understand to be a pianoid arrangement where the hammer hits chimes. Is there not another such device where the hammer hits a bell?   

       You could have the hammers hit all sorts of things. I like as an art project a varied assortment of objects, hanging, mounted and otherwise, with the only commonality that when struck they produce a tone of the appropriate pitch.   

       One could also do it with a line of chorus members. Maybe in the second act. The show could be called "Piano Mutations".
bungston, Dec 04 2013
  

       Bungston got in ahead of me. This is essentially a keyed glockenspiel. If you lengthen the hoops, it becomes chimes or tubular bells. If you close off the top, it becomes a carillon.
MechE, Dec 04 2013
  

       I'm thinking a hoop would offer sustain characteristics more simliar to a string than would the bell or bar of a glockenspiel.
doctorremulac3, Dec 04 2013
  

       I'm not convinced of that, it would depend on the mounting. If you can get it free hanging, then yes it would probably more closely approach the chimes.
MechE, Dec 04 2013
  

       Well, correct me if I'm wrong, but it seems like a closed vibraty thing like a loop or a string would use it's energy more effeciently than a bar on a glockenspiel with one loose end. The vibration energy of a string or loop bounces back into itself rather than just vibrating in space.
doctorremulac3, Dec 04 2013
  

       " just vibrating in space "   

       Ah yes, part of the niche interplanetary pornography series.
normzone, Dec 04 2013
  

       But that effect can also produce destructive interference, or weird overtones. Now the hoops are going to be relatively small for a given pitch, and getting enough metal in them to sustain an audible volume is going to be difficult.
MechE, Dec 04 2013
  

       I'm suggesting the circumference of the hoop would be the same as the length of the piano string it was replacing. Hang them in a series of concentric hoops with the minimum attachment you need to keep them from swinging around.   

       I think you'd get the same resonance characteristics as a string of the same length with regard to wave properties, harmonics, etc. Instead of the wave hitting a peg at the end of the string, changing phase and bouncing back, it would just hit the wave coming from the other side of the hoop, the far end of the point from where you struck it forming the first octive and do the same thing with regard to bouncing back, forming standing waves etc.   

       Interesting question. What's the difference between a string and a hoop? I'm not sure. Well, for starters the hoop would have to supply it's own tension whereas you pull the string on either side. But other than that, it seems like it would be the similar with regard to the way it rings when you hit it.   

       (mind wandering) I wonder if you could replace strings on a piano with wide strips of metal pulled taught to get a richer sound? Ehh, one dumb idea at a time. Plus, I should probably get back to work here and try to do something productive today.   

       Sigh.
doctorremulac3, Dec 04 2013
  

       Almost definitely not the same length for a given pitch. Remember that tension affects frequency, which is pitch, and piano wires are under a huge amount of tension (seriously, if the harp fails, pianos essentially implode). An unconstrained loop will be (I believe) a much lower pitch for the same length.
MechE, Dec 04 2013
  

       If you took a closed hoop and pressurized it ...
FlyingToaster, Dec 04 2013
  

       //An unconstrained loop will be (I believe) a much lower pitch for the same length.//   

       Yea, I think you're right.   

       Wonder if you could do that post tension slab thing that they do with concrete. Not sure what the point would be though.   

       I do want to go find a metal hoop and hit it to compare with a string sometime. I'll put that on my bucket list in the "less than exciting" category.
doctorremulac3, Dec 04 2013
  

       //wider strips of metal pulled tight//   

       Like a bandsaw? Ben awhile since I played one of those.
RayfordSteele, Dec 04 2013
  

       Yes the thing about strings is the tension; the wave is propagated along the string by the elastic stretching of the string resisting sideways deformation. An ideal string is totally flexible so there is no stiffness and no bending forces, only elastic tension. This is the complete opposite to a hoop, tube or bar, where there is no tension, and which vibrates purely from its stiffness.   

       So you could make your loop of piano wire but to tension it you need to have it magnetically levitated and spun at a ferocious RPM, so it becomes tensioned by centriputal force. Then how do you excite it without deforming it too much? A very fast hammer? The hammer usually bounces off the string... might work. Perhaps the hammer needs to move on a trajectory so that it is moving tangentially at the same speed as the wire.   

       Also how do you get the sound out? Vibrating strings themselves do not make much sound, because they displace little air. Think of an electric guitar played unplugged. Usually you attach one end to a wooden box or sheet which is excited by the string and which moves the air. Or you can have electric pickups, but they would have to be spinning at the same speed as the wire as well.   

       So each string has an enclosure that spins at ferocious RPM, the enclosure containing the levitating magnets, the pickup and the hammer.   

       I presume the string is rotated by eddy currents? Not sure how that works? How does the eddy and the levitating magnets interfere with electric pickups? Perhaps an optical pickup which shines a laser onto the string to detect its vibrations?
pocmloc, Dec 04 2013
  

       So you could raise and lower the pitch by increasing and decreasing the RPM of the spinning lasso string deal. Clever.
doctorremulac3, Dec 04 2013
  

       //f you close off the top, it becomes a carillon.   

       With an animal, when you do that, it becomes carrion. Strange that.   

       But anyway, yes this could work, but it looks like some kind of duplication, If you really wanted to tension a wire, best to stick a weight on the end and spin it, suggest hammer/wire/hammer/wire configuration.
not_morrison_rm, Dec 05 2013
  

       Sounds similar to the design of electric pianos from several decades ago, which used metal tines.
tatterdemalion, Dec 05 2013
  

       Ahh, it's a sign of the tines.
not_morrison_rm, Dec 05 2013
  

       Now, to simulate an early electric piano, you'd use a reverse Fourier transform. Ah, it's a sine of the tines.
spidermother, Dec 05 2013
  

       //This is essentially a keyed glockenspiel// - otherwise known as a 'celesta'.
hippo, Dec 05 2013
  

       [spidermother] that paper addresses stiff rings, rather than tensioned flexible loops? I presume they behave rather differently (as tensioned strings and stiff bars do)?
pocmloc, Dec 05 2013
  

       My question is how much can you ape the qualities of a string under tension by bending a cast metal wire. I know it would by necessity be thicker than a piano string, but when you bend it you'd be putting tension on it, like when you bow a saw and flex it to raise the pitch.   

       I'm wondering if you can do the post tension slab thing where you have a string in a string, the inside string being pulled very tight and kept in place by the outside part. If you had this thing under enough tension you might get the sustain qualities of a piano string. Glocks and carollions have very short sustain times, they just "chime", and in fact sound like somebody playing a bunch of doorbells. A piano can go on for a long time like the end of "A Day In The Life" by the Beatles.   

       Anyway, can you have the convenience and portability of a glockenspiel or celesta with the sustain of a piano? So the party's getting dull, you pull out your Remumax 9000 piano, everybody says "Look out! He's got a glockenspiel!" then you say "Uh uh! It's a piano!"   

       Women will want you, men will want to BE you.
doctorremulac3, Dec 05 2013
  

       //how much can you ape the qualities of a string under tension by bending a cast metal wire// Not very much - some of us have been chattering away up above about how these two things behave differently. We can carry on down below if you really want.   

       //Women will want you, men will want to BE you// What about those of us to whom this already applies, what further effect will your confused invention have?
pocmloc, Dec 05 2013
  

       Missed the idea of putting tension on the wire with a core that's pulled taught. Not sure if it would work but that was the latest concept.   

       As for your having reached the saturation point of desirability, I'm afraid there's probably not much you could gain from a miniature piano.
doctorremulac3, Dec 05 2013
  

       [Insert 12-inch pianist joke]
tatterdemalion, Dec 05 2013
  

       [pocmloc] //that paper addresses stiff rings, rather than tensioned flexible loops?//   

       I thought stiff rings was precisely what the idea proposed. As discussed above, a ring shape can only be maintained by stiffness, or by applying a force to create tension (e.g. by spinning).   

       It might indeed be possible to create harmonic overtones in rings, using sophisticated materials and manufacturing. After all, the first harmonic bell-shaped bells were only made a decade or so ago.   

       Anyway, (1) pianos aren't quite harmonic in the first place (because the strings are relatively thick), and (2) What's the obsession with pianos, and the need to copy them? A good digital piano will sound much closer to a real piano than any mechanical simulade, whereas a bunch of rings struck by hammers would be a fun thing in its own right.
spidermother, Dec 06 2013
  
      
[annotate]
  


 

back: main index

business  computer  culture  fashion  food  halfbakery  home  other  product  public  science  sport  vehicle