Wind Chimes

Wind chimes are arrangements of metal, glass, wood, shell, pottery etc., that produce sound when the wind blows past them.  They can range in size from a few inches to several feet and retail from a few dollars to a several hundred dollars.  A wind chime must be built with fairly tight clearances if it is to make sound in gentle breezes.  Glass and pottery wind chimes must normally be hung where they will be protected from strong winds which will break the glass and pottery elements. The sound of a chime depends on the material, the thickness of the material, the length of the tubes or items, and the material of the striker.  Note that it is possible to make a wind chime without a striker, but it typically doesn't work very well because all the elements swing together instead of striking. An exception is when multiple flat or slightly curved pieces, such as seashells are placed close together so they spin or oscillate enough to strike those near by.   2006-03-14

Terminology
Chime - The element that actually makes the sound - a tube or flat piece
Striker - The moving part that hits the chimes, as a clapper in a bell. Chimes may also hit each other or another element.
Flapper - The device that catches the wind and moves the striker(s); light strikers may be blown by wind into each other.
Support - Disk, wire or shape from which chimes are hung - spaces the chimes
Line - The wires or threads holding the chimes from the support.
Element - Other parts of the unit, which may be purely decorative like flowers or leaves added,  a solid core for the chimes to be blown against like the glass globes below or some other purpose like the solar cells and LED's in the same unit.

Any attempt to make wind chimes should begin with testing the sound made by the materials for quality and quantity.  A first test can be using a paper clip or pliers to hold the piece while it is rapped with material like the planned striker(s). A further test taking a bit of time is to use clear household glue to attach a piece of thread (letting it dry) so it will hang freely and the sound be more clearly heard.  When I made miniature, three element wind chimes from colored glass, I fused a hook into each one and hung them from thread loops to test their sound together - if acceptable, the final threads were knotted and glued.

Wind chimes do not have to make musical ringing tone sounds.  Bamboo as tubes or splits and sea shells hung closely together are used to make a percussion sound with more or less musical tone to it - I saw some in a Big Lots the other day.  In a very quiet environment, something that looks like a wind chime but with paper or other light soft elements can provide a visual variety and some sound of very soothing quality.

Metal tube wind chimes can be built of a number of materials using the rules given in the table below.  Some materials and even some alloys of materials are dull and will not produce a reasonable sound.  Any tube of the same length, supported at the same point, will produce the same note, but as a trumpet and clarinet can produce the same note with a considerably different tone, the tone will vary depending on material and striking method.  Brass and aluminum are the most commonly used, steel making a very heavy chime.  Metal tubes make a considerably different initial sound when struck by a metal clapper compared to a wood clapper and different woods - harder and softer - with different shapes - square or round edged - will also produce different sounds.

This is an example of a wind chime made with fused glass chimes hanging from a shaped cherry wood support (the insert shows the color in moderate light - the contrast with the white background darkens the same support in the hanging version.)  Glass requires that the chimes be hung close together and on long threads to make sound in gentle breezes and that they be hung where strong winds won't bang and break them. The chime pieces shown have nichrome "stamen" wire fused between the large backing and the top small piece.  Making these things balance can be a bit tricky and this one already had the loops installed, so the pieces were selected to fit and not for best appearance.  When I was making these up on demand at a craft show, I would drill the holes for the pins by hand to match the chime pieces the customer selected.  The pins with loops are sold at lamp supply stores for hanging the crystals on shades and chandeliers. The picture shows 3 pieces of glass plus their shadows on a white background in bright sun.  The photo below shows some of the various cut wood and fused glass pieces.  2010-01-17

Recently, here in Texas, I have had trouble with the tubes being stuffed with grass by some insect and that or another laying eggs that hatch into tiny grasshoppers.  The first sign I had was wisps of grass hanging out the bottom, but of course, it also dulls the sound, acting as padding on the inside.  A stiff wire, like coat hanger wire, can push the trash out so a clear view through the tube can be seen. 2006-06-26

The source of original information for most of this table is
http://www.metalwebnews.com/howto/wchime/wchime.html

1

2

3

4

5

6

7

8

Eight Chimes: 16 7/8

16 7/8

17 3/8

18 7/16

19 1/2

20 3/4

21 3/8

22 3/4

24 1/8

fraction

0.6995

0.7202

0.7642

0.8083

0.8601

0.8860

0.9430

1

Viewed from the top, he shows a hanging order starting at the 12:00 position of chime
Since any two adjacent are in tune, the clapper can hit anywhere.

1

5

2

6

3

7

4

and 8

For 1/2" OD tubing with a 2-inch clapper, the chimes are placed on a 4.5-inch diameter.
These lengths are close to theory for a major chord, but rounded to the nearest 16th

Six Chimes: 16 5/8

16 5/9

17 5/8

19 1/4

20 7/16

21 5/8

23 3/4

0.697

0.742

0.811

0.861

0.911

1

 Hang distance at 0.2242

3 23/32

3 30/32

4 10/32

4 19/32

4 27/32

5 10/32

8 3/8

8 29/32

9 23/32

10 5/16

10 15/16

12

 Hang distance at 0.2242

1 28/32

2

2 6/32

2 10/32

2 14/32

2 22/32

0.3285

0.4713

0.6351

0.7835

0.9105

1

A six-element chime hung with the same spacing as the 8 element one above requires leaving two gaps so the adjacent discordant chimes will not normally be struck.

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1

4

2

(blank)

5

3

and 6.

Another consideration is how/where to hang each chime. It has been reported that hanging them .2242 X length from the end works well because this is a node point of the fundamental frequency (in other words it wiggles less there!). If you hang them using nylon fishing line be certain to deburr the hole and smooth it and don't place anything valuable under it (like a glass table)!. Also note the actual distance varies for each chime.  Also note the actual distance varies for each chime.

On many commercial chimes, the clapper is half way down the longest chime and others are hung so mid-point is struck.
This is merely a matter of changing the length of hanging thread so short elements are on longer thread.

i

One formula was presented in a book Music, Physics and Engineering" by Olsen for a tube free at both ends:

{radius of gyration of a hollow circular cylinder}

My mother-in-law was given a set of large wind chimes by her other daughter.  These are aluminum tubing and costly (a couple of hundred dollars) as I know from working at Elliott's.  They also have a lovely deep tone that rings for some time.  I was planning on making a set for us, although the cost of 2" aluminum tubing was discouraging. The original is 2" aluminum tubing with 1/8" wall, silver inside and anodized blue outside. (right)  A metal shell acts as spreader for the support lines.  An 1/8"x7" aluminum disk is the sail at the bottom and a 3/4"x6.5" hard disk with rounded edge is the striker.  The pipes are hung so the striker is striking 44% down their length and suspension is from a rod through the wall at 22% of length with the cord tied in the middle.
  After doing a bunch of measurements (below) and trying some stuff with steel pipe and conduit scraps, I decided to buy a 10 foot length of 1-1/2 (nominal) EMT conduit about 2" in OD and build what I could from that length. If worked out, I would go further.  Various experiments had convinced me that the relative weights of the striker and the sail were important, so I worked to compute those. Basically, I have been making my strikers bigger and heavier so swinging goes on longer and making them flat instead of bending them for direction.
  I cut the pieces of EMT on my cheap metal band saw and after filing or grinding to smooth the burred ends, I drilled 5/32 for 9 gauge steel wire for the hanger rods.  The rods were gently curved and cut about 1/8-1/4" longer than the OD.  Two tricks helped install the rods 1) Looking down the tube from the end, the light from the hole reflecting off the end of the wire helped get it in the hole, & 2) Holding the wire end with finger tips, the hanging cord with a steel nut on one end was slid down inside the tube until past the rod, then the tube was rolled over and inverted so the nut fell back taking the cord around the rod.  Holding both ends of the cord pulled tight to curve the rod upward in the tube, a hammer was used with the end of the rod on a vice to peen the ends, bowing the rod somewhat more and widening the ends.  When done, the nut was taken off the cord, a stopper knot tied in the end, and a slip knot added to tighten on the rod by pulling. Alt.Description
For the preliminary test, an existing steel ring 1/2"x1/2"x6"OD was used and a hardwood disk was cut to fit between the pipes with a small gap. A clear glass sheet was drilled (after several failures splitting the glass) and roughly shaped.  The sound was nice.
For the final installation a drawing was made to scale using measurements off the image (screen calipers) for pipe spacing and disk size.  A steel ring of flat 3/4"x1/8" was cut to be 9.5" OD and welded and rounded.  The pipes were mounted at the 1/6 points while suspension was at the 1/3rd points.  Using a ring allowed retying the knots to raise or lower the pipes.  A larger hardwood disk was cut in two halves from a narrow scrap board and edge glued and sanded including rounding the edge somewhat.  A small hole in the center admitted a stiff stainless steel wire for hanging.  Loops at top and bottom of the wire were bent for string and a loop twisted near the middle positioned the disk on the wire. A white glass disk 6.5" across was cut from on hand glass and drilled for hanging.  A wire was looped through the drilled hole to avoid glass chafing the string. Sounds good. 2008-03-18
During development of various wind chimes, using brass tubes and steel washers on strikers, steel pipe lengths were cut from pieces left at curb for trash.  First as double then as triple, these were hung, as shown above right, to work on different tones of steel same length.  I believe the sail and striker both need to be heavier than shown. 2008-03-19