Chronology Current Month Current Thread Current Date
[Year List] [Month List (current year)] [Date Index] [Thread Index] [Thread Prev] [Thread Next] [Date Prev] [Date Next]

Re: Chimes; Waves in Pipes, Rods, Bars, etc



At 17:23 1/1/98 -0500, Durig Lewis wrote:
I am considering a unit on waves and want to get my students to make wind
chimes and xylophones. I now realize that I don't know as much about it as
I used to think I did. How do I calculate the frequency of a wave in a
struck pipe, rod, or bar. Which plays the bigger role: the transverse or
the longitudinal wave in the pipe. How does the air in the pipe or around a
rod or bar affect the tuning. I have heard that humidity affects even the
tuning of a xylophone.

DurigLewis@worldnet.att.net

This is the URL for a very practical piece on windchime construction:

http://users.why.net/wgray/www/howto/wchime/wchime.html


This is a public newsgroup post on chimes in transverse
vibration, xylophone style - I think you will see how they can be
made - quoted here without permission:

**********************************************************************
Subject: Re: "Zen" chime question
From: kinsler@froggy.frognet.net (Mark Kinsler)
Date: 1997/11/26
Message-ID: <65i3ut$jv6@froggy.frognet.net>
Newsgroups: rec.crafts.metalworking
[More Headers]


P'rfesser <terry.mccreary@murraystate.edu> wrote:
I saw a different kind of alarm clock in a catalog. It had what the
catalog called a "zen chime", a metal rod suspended by two strings
about a quarter the length from each end of the rod. It reminded me
of a similar device I saw in Hallmark. You tap it and it seems to
ring for about a minute. Very soothing.
Anyone know more about this: type of rod, exactly where to support
it, how to maximize the ringing time, etc.? Thanks, group.

You can do this with almost any piece of metal. A long, thin wrench works
well. You determine the nodes, which is where you place the
support strings, by experiment. Brass or bronze is
supposed to work better than steel, but I get swell notes
from a rather rusty piece of reinforcing rod. Wander over to the
music school and have a look at a vibraphone and you'll see where to
support the bars.

You can ring a lot of things. Wood bars, of course, make a xylophone.
Most ceramics ring well (I have to try flower pots sometime.) A tube (try
electrical conduit) has low sectional density, which I think is why it
will give you a very low note for its length--hence, tubular chimes.

Mark Kinsler
************************************************************************