As Ron says, stiffness and inertia are the issue. Think of a reed organ. If you file a little off the free end of the reed, the rotational inertia is reduced, and it gets sharper. To lower it, you file a little off near the attached end, making it more flexible, and the pitch gets lower. A bell puts you into 3 dimensions, so it's harder to visualize, but the trick is WHERE you remove the material. If you grind off material from the open end of the bell, it should go up. If I had time, I'd try this for you. Do you have any cheap decorative bells around from Christmas? Play with one of them. --John Ashcraft On Tue, Jan 11, 2011 at 2:10 PM, Ron Nossaman <rnossaman at cox.net> wrote: > On 1/11/2011 3:42 PM, David B. Stang wrote: > > Can someone help me get my pea-brained head around the fact that >> removing material from a bell would LOWER its pitch, where I would >> have thought that removing material would make it lighter and more >> flexible, and therefore RAISE the pitch. >> > > With anything vibrational, stiffer raises pitch, more flexible lowers it. > Adding mass lowers pitch, removing some raises it. How much of which, and > where is the problem. It seems you made it more flexible than light. > > > > Any ideas about what to do now? Drill the other 11? >> Or, does anybody have a spare D6 metal bell lying around? >> Thanks. >> > > Grind a little off the end (rim) and make it shorter? I don't know what it > looks like, so that's a guess in the dark. > Ron N > -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://ptg.org/pipermail/pianotech.php/attachments/20110111/a337198a/attachment.htm>
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