Re: Force Versus Distance of a Pneumatic
By John Grant
Hi Robbie (and List),
On Fri, 22 Mar 96 01:05:39 PST Automatic Music Mailing List 96.03.21, Robbie Rhodes wrote:
>
> Subject: Force versus distance of a pneumatic
>
> Has anybody any numerical data on how the force of a simple "board"
> pneumatic varies with the opening?
<snip>
I'm a bit confused here, could this be an apples/oranges type discussion? The "force" of this pneumatic would effect the SPEED of operation of the hammer rail but would NOT (IMHO) directly affect the loudness of the note. (This assumes that you consider the positioning of the hammer rail "binary", that is, either at rest or raised to its maximum.) Note intensity would be affected by the action geometry, i.e., regulation, blow distance, amount of lost motion (and to what degree that is compensated for), etc, but would, I believe, be independent of how fast the hammer rail reached its raised position. (Again, notes struck while the rail is in motion are outside this discussion.) I'm also not so sure that having the blow distance shortened to 50% of its normal value necessarily produces (or even predicts) a 3 dB reduction in sound intensity. The physics of a moving hammer, i.e., mass, acceleration, kinetic energy, etc. are QUITE beyond my ability to analyize, but they ARE complicated. The physics of why a simple wedge pneumatic develops is greatest force at its full open position has, I believe, been discussed in one or more articles in the AMICA bulletin, although I have no specific references at hand. Perhaps someone else can provide this. Have I missed some other subtle point here?
-John Grant
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(Message sent Fri 22 Mar 1996, 15:44:13 GMT, from time zone GMT-0800.) |
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