If you just want pre-calculated dimensions go here
or calculate your own dimensions, go here and download the DIY Wind Chime Calculator.

As my good neighbor, Bob, pointed out when faced with the challenge of designing a new state-of-the-art toaster, you first determine what makes toast, toast; rather than dried bread before you design a great toaster, a fascinating story.

Clearly the question should have been, what makes a chime a chime, rather than what musical notes should be selected when designing a set of wind chimes. I had originally asked that question and now find that I should have also asked, "What makes a good chime"?

In 2001 I took a month to study, experiment, build, and test nine sets of pentatonic scale (CDEGA) chimes for fundamental C2 through C7 for Christmas presents. The gifts were well received and sounded okay. However, from my research, I found some internet information good and some information inaccurate, misleading or wrong. This is not surprising considering the tremendous breadth of information available on the web.

While I would not consider myself an expert by any definition, and the fact that I have absolutely no musical background, I consider my findings valuable for the understanding of tubular bells and useful if you desire to build a great set of wind chimes. My experience with this project is presented here and may help you in an effort to design a great set of wind chimes. Updates continue almost monthly as the research continues into 2012. BTW, another engineer, Chucks Chimes, has a lot of good information on his web site.

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What Is A Chime?
What is a chime? Tubular bells (chimes) were developed in the 1880's when using regular bells became impractical in an orchestra setting because their sound so closely imitates church bells. Now, that sounds simple enough but imbedded in that explanation resides two definitions. One definition is "a chime imitates a bell" and the other definition is that "a chime does not imitate a bell". While I found those two definitions to be true I also found that there are about three categories of chimes.

The first category has a note range from about C6 through the C8 octave. Not unlike other percussion instruments this category is characterized by an audible fundamental strike frequency (a noticeable pure tone) with overtones mostly absent. Overtones have minimal contribution to the perceived musical note. This note range is not particularly pleasing to the ear and is definitely a "non-bell" sounding chime. In addition, the loudness is typically low caused by the short length of the chime causing low radiating surface for the higher notes. The rapid attenuation of high frequencies in the environment cause this note range to quickly diminish at a distance.

The second category has a note range from about C4 through most of the C6 octave. The fundamental strike frequency is mostly audible and some overtones contribute to the perceived sound. The perceived note is not the fundamental strike frequency and not the overtones, but a combination of both that produce a perceived musical note. The sound is acceptable but not great. This has an "almost-bell" sound and sounds fairly good, but not particularly melodious. The loudness is acceptable but not great.

The third category has a note range of about C2 through most of the C4 octave. The fundamental strike frequency is present but audibly absent and there are a host of overtones. The perceived sound is not the fundamental strike frequency and not the overtones, but an imaginary note created by the combination of the overtones. To the ear this is a very melodious sound and clearly a "bell-like" sounding chime. The larger physical size for this note range causes the loudness to be quite adequate and easily supports radiation for the many overtones.

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 The overtone structure for a chime in not an integer harmonic as in string instruments but instead, non-harmonic as in other percussion instruments. When the chime is supported at the first overtone node the higher partials are dampened and the fundamental strike frequency remains. Overtones exist and are multiples of the fundamental multiplied by X 2.76, X 5.40, X 8.93, X 13.34, X 18.64 and X 31.87. If we could hear the complete compliment of overtones for each note of a chime tube, it would be a most wonderful "bell-like" sound. Unfortunately, not all of the overtones can be supported for all possible lengths of a chime tube. 

For example, a chime cut for C2, the fundamental frequency is audibly absent along with little audible contribution from the first overtone. The remaining overtones combine to produce a perceived musical note. The perceived note does not coincide with any specific overtone and is difficult to measure without a frequency spectrum analyzer.

You can see from the display to the right (click to expand) that a chime cut for 272.5 Hz (near C₄^#), has two characteristics. The first characteristic is the sound when the chime is first struck, the "Strike Note". It comprises both the fundamental and the first four overtones, and has that traditional chime sound for a short period of time.

The 2nd, 3rd and 4th overtones are present and contribute to the strike note but attenuate quickly. They have little contribution to the lingering perceived sound, aka "sustain time or hang-time"

The 1st overtone contributes for about two seconds and rapidly deteriorates. The remaining sound is solely the fundamental strike frequency. Note the long hang time for the fundamental.

In contrast to the above example, the sound for a chime cut at fundamental C6 and up is mostly the fundamental, and the overtones are audibly absent or mostly absent.

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The perceived musical note from a chime is not simply the fundamental frequency. To gain a better understanding of the perceived note I examined a set of orchestra chimes manufactured by Premier of England. The set was 1.5" chrome plated brass with a wall thickness of .0625 inches and ranged from C5 (523.30 Hz) to G6 (1568.00 Hz). The length of C5 was 62.625 inches. The fundamental frequency for this length is around 65 Hz, yet the perceived note is C5 at 523 Hz. The fundamental strike frequency of 65 Hz and the first over tone at 179.4 Hz (65 x 2.76 = 179.4 Hz) are audibly absent. In fact, even the second overtone at 351 Hz will not be strong in loudness. The remaining beam bending overtones (mechanical vibration modes) combined to produce what the ear hears acoustically, which is C5 at 523 Hz, yet there is not a specific overtone at that exact frequency.

In addition, an orchestra chime is not supported by the classical wind chime method using a string through the chime, but instead, is fitted with an end cap that contains a small hole through which a steel cable supports the chime. From my testing I find that the end cap not only enhances the "Bell-Like" sound by increasing the duration of the first overtone, but it also lowers the fundamental frequency by about 4% to 12 % from calculated values depending on tube material and diameter. More on this at "Location for Chime Tube Support".

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The physics of a perceived note:
To make a great set of wind chimes it is not necessary to understand why a chime note behaves as it does, but in my case I find it necessary. It turns out that several other people have spent time investigating the "missing fundamental" and the "perceived note' from a chime. Some sources are:

Hyper Physics  Wind Chime Physics   Paper by: Kyle Forinash, John Richie and Tim Jones

http://en.wikipedia.org/wiki/Missing_fundamental

I spoke with the folks at Musser Chimes and confirmed that indeed the process of tuning a chime is a complex process of accounting for all frequencies from the fundamental through the many overtones, using math calculations and grinding to length, to the achieve the final note. 

An integral part of the "perceived note" effect is the sensitivity of the human ear to loudness and to frequency for various notes. You can see the loudness sensitivity range and frequency sensitivity range of the ear by viewing the Fletcher/Munson "Equal Loudness Curves" found HERE. Clearly the ear has more sensitivity in the range from about 300 Hz to about 4 KHz than at other frequencies, and helps to explain why we can not always hear all the overtones, even is they are present.

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Chime Emulation:
There is a terrific piece of freeware called "Wind Chime Designer V2.0", 1997-2006, by Greg Phillips that will emulate a chime for any note in many different scales. It will help you determine what note(s) sound good on a chime and what scale to use. In addition, there is a comparison calculator that can determine the length of tube once you have a measured length as a reference.

Wind Chime Designer by Greg Phillips Version 2.0              Wind Chime Designer Instructions  PDF

If you have trouble unzipping Greg's new version here are the two files you need. Chime32A.exe and TUNING.DAT Using right mouse, select "Save Target As" and save to a folder of your choice. Place both files in the same folder and run the exe file.

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 Note Selection
Note selection is mostly a personal choice. I selected the pentatonic scale to build the nine sets of chimes; however, I discovered later in the year there is a better choice. The pentatonic scale was a safe choice and sounds good close to the chime set but not so good at a distance. The problem at a distance is the ear has difficulty detecting the separate notes of the pentatonic scale (CDEGA). All notes (CDEGA) had a strong tendency to sound alike at a distance of 150 feet.

Later on we determined a better approach is to use the C9 cord (C E G Bb D) for a five chime set.

You can listen to the C9 cord here www.8notes.com/piano_chord_chart/C9.asp   Select the C9 Cord, not C m9 & not C maj9.

If your interest is making the chime set sound good at a distance of say 150 feet or more, you need to consider increasing the diameter of the tubing from the traditional sizes. A set of chimes designed for the C2 to the C3 octave have good acoustic radiation properties close to the set but so good not far away. I suggest you consider a diameter at least 3 inch or more, 4" to 6" is better.

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Tuning:
If you are attempting to create exact notes for an orchestra setting, exact tuning is required, and the use of an electronic tuning device or a good tuning ear is necessary, and it is a lot of work! On the other hand, if you desire a good sounding set of chimes but do not need orchestra accuracy then cutting a tube to the length suggested by the formula listed at the bottom of this page should be adequate. For your convenience, pre-calculated lengths for various materials and sizes are listed in the table below in addition you can calculate your own dimensions using this DIY Excel sheet.

Not all tubing is created equal. Be aware that some tubing may produce a beating effect when struck. This is often due to variations in the cross section of the tubing from variations and inconsistencies in the manufacturing process. The Elasticity and the Density of the tubing will be different depending on where the tube is struck. The tube will produce two frequencies and these two frequencies will produce the beating effect. Some people enjoy this type of effect and others may find it annoying. If you want to avoid this wah-wah effect, make sure you acquire high quality tubing – or test a small piece before buying in bulk. While some tubing may be considered poor quality for musical requirements, it may be just fine for structural needs. The problem with tubing that exhibits this effect is that it makes precise tuning more difficult.. Listen HERE (mp3) to the beating sound for the tube shown to the right.

 If you can determine the exact Material Density and the exact Modulus of Elasticity, enter those parameters into the DIY Calculator "Data" page when using the DIY calculator.

I want to emphasize that good tuning will certainly help to accurately produce the appropriate overtones for the selected note, particularly for the higher note ranges.

In addition to the many overtones present for each chime we have the difficulty of knowing which overtones are prominent for each note because of the ear's sensitivity as represented by "The Equal Loudness Curves". As you might suspect, the loudness of a particular overtone changes as we move up the scale. For a typical ear sensitivity range of 300 Hz to 3 KHz, see the sheet named 300Hz-3KHz. Obviously this is not the entire audible range of the ear but is presented as a simple example of the limited ability of the ear to hear all the frequencies generated by the overtone structure. In particular, the range of C2 to C3 contain a large number of audible overtones while the range of C5 to C7 contains very few. The range of C2 to C4 produces the most melodious sound and is the easiest set of chimes to build. Precise tuning (+ / - .1Hz) is not required.

Caution at a distance . . .
I often hear comments like "I have a set of chimes on my deck and they sound great; however, I was over to my neighbors the other day and my chimes do not sound so good. In fact, they sound "out of tune", why is this?". The answer lies in the conditions that make up the note for the chime. As mentioned above, a chime note is a combination of the fundamental strike frequency and the many overtones. Some of the overtones attenuate more than others at a distance. The original combination of strike frequency and overtones are not the same at a distance.

Remember, not always does the fundamental frequency contribute to the note and not always are there many overtones for a given note. The actual note depends on exactly where in the musical scale the chime is operating. When you have a chime that contains a larger number of overtones that are located in the higher frequencies, and mostly missing the fundamental, you can get this distance effect. High frequencies attenuate more quickly in the atmosphere than do the lower frequencies. At a distance you are not hearing the same sound you hear close in. Some of the high frequencies can be greatly attenuated or missing. The chime can sound completely different under these conditions. Typically this occurs when you select notes in the lower part of the scale.

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Location for chime tube mechanical support:
Chime support is at either of two locations. The more tubular bell sounding chime is when the chime tube is supported by a cable through a hole in an end cap. The end cap lowers the fundamental frequency and some associated overtones from values calculated by the DIY calculator or pre-calculated charts. For 1/2" copper pipe, type L, the fundamental is lowered by about 3% to 6% from calculated values on this page. For 3/4" type L copper pipe, the fundamental is lowered by about 11% to 12%. The good news is that the end cap noticeably increases the duration for the first overtone and the chime has a much more bell-like sound. Look at these two spectral waterfall displays and specifically compare the hang time of the 1st overtone. You will notice the a considerable increase in sustain time for the end cap supported tube.

Waterfall display for a chime tube supported by a hole in the end cap. Similar to the traditional orchestra chime	Waterfall display for a chime tube supported at the traditional 1st overtone node	End Cap Support

The second support method uses the traditional 1st overtone node which is 22.42 % from the either end. See the Free Bar Vibrational Modes at the right. I found it easy to destroy the Q (hang-time or sustain-time) of a hi-Q chime by improper support. Thin wire, rubber grommets and plastic inserts all worked but contributed to a lowering of the Q. Nylon plumb line with no inserts worked best and the line is available in a variety of colors. Of course it is necessary to de-burr and burnish the drilled support holes to minimize wear and tear of the line. Sources for rubber or plastic grommets include Radio Shack, Home Depot, Lowes and your local model airplane & hobby store.

You can support the chime at the second or third overtone nodes but it is not recommended. All charts and calculations on this page are for support at the first overtone node. See reference at right.

BTY, for acoustics, it is easy to confuse overtones and harmonics. Overtones = Harmonics -1, or Harmonics = Overtones + 1. This acoustic harmonic relationship has no connection to the Radio Frequency definition of harmonics.

1st Overtone                             2nd Overtone                               3rd Overtone
 Animations courtesy of Dr. Daniel A. Russell at Kettering University, Flint, Mi

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A variety of methods can be used for 1st node mechanical support

Method 1	Method 2	Method 3	Method 4
Most typical and the most stable in high winds.	One support point and somewhat less stable than method 1. More difficult to de-burr the inside support hole.	May be more pleasing to the eye with less visible string. Less stable that method 1. More difficult to de-burr the inside support hole.	A mounting pin eliminates the string knot and provides a cleaner look.

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Centering the support line on the pin for this example I used #12 copper wire but you can use what works best for you.

Method suggested by Chuck from Columbus

Site visitor "Tom" has a good suggestion for an easier way to accomplish the wire method above. Buy some of the "batwing" type binder clips, remove the arms, stretch them out a little, and then squeeze one arm into the pipe, and, using needle nose pliers, wiggle the arm until the tips pop out of the holes. Be sure to attach your hanger wire first. The arms tend to be self centering. The batwing binder clips come in different sizes, so you can match the clip to the diameter of the pipe. The diameter of the arms increase with the size of the clip, so make sure to check the diameter of the arm before you drill the pipes. The batwing binder clips have the metal clip in the center, and the "wings" (wire extensions), are used to open the metal clip. Thanks Tom . . .

Support Plate
The top support plate can be of most any design in most any shape as long as the chimes are supported so the striker can effectively contact the chime tube. If you desire the traditional round top support plate we have a DIY Support Plate Calculator to assist you. Also included in the main DIY Calculator below.

Requires any of the following to view and execute:
MS Excel Viewer (Free) Get it here; or Sun Open Office (Free) Get it here; or MS Excel (Cost $) Get it here;

The calculator ask you to decide on the Chime Diameter (CD), the Striker Diameter (SD) and the clearance between the striker and the chime tube (D). The calculator provides the correct location for placing the chimes (R) and (CS), and the diameter of the support plate (PD). Instructions for use are included with the calculator.

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Frequency measurement:
Measuring the exact fundamental frequency of the chime is quite easy. All you need is a microphone, some tuning software and a method to support the tube at it's nodes. A few scrap pieces of wood to make a couple of "U" brackets, rubber bands and you're in business. Most any computer microphone will work, in fact I have even used the microphone on a headset that I use for Skype and it worked quite well.

A good software solution for frequency measurement is to use a tuning program. I found a program, "Tune Lab Pro" worked well. This is good for frequency measurements but completely ignore the musical note display because it's set up for string instruments which are integer harmonic and chimes are non-harmonic. A few additional sources are listed below.

Tune Lab Pro version 4 Good for frequency measurement only, not for musical notes from chimes

DL4YHF's Amateur Radio Software: Audio Spectrum Analyzer ("Spectrum Lab")
Good for fundamental frequency and overtone frequency measurement.

OscilloMeter Good for fundamental frequency and overtone frequency measurement.

A commercial electronic guitar tuner by Korg worked well for fundamental frequency measurements but can be tricky because of the short hang-time from the chime. Good for frequency measurement only, not for musical notes from chimes

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Mechanical support for frequency measurement:
I had good success supporting the chime horizontally at both nodes, one by a rubber band, and at the other node by a thin wire attached to an accelerometer. The accelerometer eliminated the annoying background noise when using a microphone.

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The Wind Chime Striker:
Orchestra chimes, of course, need a human to strike the chime and a rawhide-covered rubber mallet works well for that application. However, for wind chimes there is little strike energy available from the wind catcher so preserving and applying that energy is the challenge. I tested a number of strikers and found that considerable strike energy can be applied by using a 2" diameter oak disk machined to a knife-edge and loaded with about 1oz of weight. I also used a small 1/16-inch brass tube about 5 inches long as an axle for the disk. The axle keeps the disk horizontal during rapid and sudden movements from high winds.

If you live in a area with little wind then eliminating the 1oz weight may be desirable. See the next section on striker location for more info on striker weight and location.

The small diameter disk was used to minimize the striker from contacting more than one chime at a time. Attempting to strike several chimes simultaneously to produce a chord was a waste of strike energy and ineffective. There is little strike energy available to start with and attempting to strike a musical cord with the striker is, at best, disappointing. A larger diameter disk may be preferred as it is less likely to be blown to the outside of the chime circular mounting profile during high winds.

There are two locations on the chime that work well for striking. If you are building a "non-bell sounding chime" for fundamental C6 and up, striking at the center or the end works equally well. Striking the center assures excitation of the second harmonic but, you run the risk of not exciting the odd harmonics.

On the other hand, if you are building a "bell sounding" chime it is important to excite all possible modes for good overtone representation. This is easily accomplished by striking at the very end of the chime. Striking at the end will assure the excitation of all modes since all modes exhibit high impedance at the end of the chime. I much prefer this method.

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A Better "Ringer Dinger"
The traditional striker described above works well, however from comments above we remember that not all tubing is created equal and the chime can sound different depending on where it is struck, at the end or at the center. I was looking for an approach that would produce a more consistent sound. To my surprise I believe there is a better way. Striking the chime at the very end consistently produced a much better sound that striking near the end or in the center. As mentioned above, you run the risk of not exciting the odd harmonics by striking at the center. This should not be been surprising since orchestra chimes are struck at the end. Try it for your self. On most chimes it made a difference except on the high notes where few auditable overtones exist.

A tapered striker was used to accomplish this goal and to assure the striking of all chimes at the very end. If you have access to a wood lathe, it's an easy task to machine a tapered striker from wood. I used pressure treated stock because of its softness. It is important to under-cut the inside to minimize excessive weight which will inhibit striker resonance.

This heavier striker (to the left & right) requires more energy to move and makes support line resonance more difficult. (see Striker Location, below). The choice of material depends on the note selection. For lower frequency chimes a soft, heavy striker is best and for higher frequency chimes a harder, lighter striker works better.

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The Wind Chime Striker Location a new approach "The Resonate Striker"

I happen to live in a wooded area with little wind and have struggled to achieve good strike energy with low winds. With that in mind, I set out to improve the low wind performance of the striker.

The objective is to maximize striker movement with little input energy. The easy solution was to resonate the line holding both the striker and the catcher using the second mode bending principle. This resonance will help to amplify and sustain the motion of the striker with little input energy from the wind.

You can easily recognize this movement by using both hands to hold a string vertically and have a second person pluck the center of the string. The natural resonance of the string will cause the center to move back and forth horizontally. If you position the striker at the exact center between the top support and the catcher you can achieve this resonance.

 When you attempt to resonate the support line, I suggest a light weight striker to assist with good resonance. A heavy striker will not resonate. On the other hand, for medium to high winds and for a non-resonate mounting, the catcher/sail should have a weight equal to about 25% of the striker.

When resonance is working well you will notice as the catcher comes to rest, the striker will continue to bounce off the chimes for a few more strikes, an indication of dissipating the stored energy from resonance. See this Resonant Striker VIDEO WMV, for a demo. Notice the large movement of the striker compared with little movement from the catcher.

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The Wind Chime Wind Catcher, a new approach. "The Unstable Catcher"

Traditional wind catchers work well, hang vertically, and can be configured in a variety of materials, sizes and shapes. The objective of a better catcher is to cause the catcher to become unstable and to move the striker in a more circular motion from the force of single-direction winds and to better capture the effect of turbulence.

First, my dissatisfaction with the traditional wind catcher is that in single-direction winds it has a tendency to cause the striker to swing to and from the direction of the wind and not strike adjacent chimes. Much like the periodic motion from the pendulum effect and sounding like ding-dong, ding-dong, etc.

Secondly, with turbulent winds the traditional catcher does not do a good job of contacting all the chimes. Certainly, the wind is random in direction and the catcher will eventually cause the striker to contact all chimes, but I wondered if there might be a better way?

Thirdly, as you know, winds vary considerably across the country from low speed to high speed and from predominately single-direction winds to mostly turbulence winds, and in any combination. The best solution for you will depend on your type of wind. You may need to try a few different catchers for your best success..

From some windmill research I did several years ago I recall that wind, close to the ground, can behave quite differently than winds aloft. As you know, wind can be quite turbulent and often does not blow horizontally as intuition would suggest. Instead, it is a two dimensional force simultaneously blowing in both the horizontal direction and the vertical direction. Swirling and blowing uphill, downhill, and horizontally. Wind sheer is a common occurrence close to the ground and perhaps we can exploit that force to make a better wind catcher.

To better understand wind turbulence mixed with single-direction winds watch this 20 sec WMV, Bi-Directional Wind Vein VIDEO showing a bi-directional wind vein mounted on my deck. You probably noticed the swirling motion mixed with single-direction winds and the random uphill and downhill movement, pitch & yaw. Let's take advantage of this movement to create a striker movement that is somewhat rotational in nature and does a better job of striking all the chimes.

To better capture turbulence the solution is quite simple. Mount the catcher at 45^O to the horizontal so as to catch the pitch and yaw forces. See the picture to the left and right for an easy solution. Thread the support line through two small holes next to the center of an old CD disk and tie the knot slightly off-center to create the 45^O slope. You may need to glue the line in place for the long term.

A site visitor (David) writes to say he has a simple solution to tilting the catcher that does not require drilling holes. That is to place the support line in the hole and tie to the line an object larger than the hole. Now you have a tilted catcher and a sun catcher, all-in-one. See picture at left.
Thanks David for a great idea.

A second approach to capturing turbulence and to cause the striker to move in a more circular motion is to hang the catcher perfectly horizontal. Counter intuitive, I agree, but depending on your particular type of wind it can work surprising well.

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Solving the "Ding-Dong"

With a single direction wind there is little one can do to avoid the annoying ding-dong sound despite all the innovative catcher designs I have seen. The above "angle-mount catcher" works and attempts to solve the "Ding-Dong" problem, but is not the ultimate answer. The real answer is to accept the "ding-dong" effect and rotate the chime set to take advantage of the periodic motion from the striker.

Rotation is easily accomplished by inserting a few paddles about the circumference of the support plate. As my wife says, "they look like "Mickey Mouse Ears". Hang the top support plate using a sturdy but flexible line. For light weight chimes I use nylon plumbing line from the local building supply store. Yes, nylon plumbing line even supports a Cincinnati snow load.

Heavy chimes require a more reliable material. You can either double up the nylon line or in my case, I use 1/8" nylon pull-line used for pulling wires through electrical conduit.

This approach has a tendency to self regulate the amount of rotation. The chime set will wind-up until the support line can no longer accept twist and then un-wind as the striker continues to function. In addition, the higher the wind velocity the less the chimes seem to rotate, which is good for high winds.

As an example, here is a "Rotating Wind Chime Part 1 of 2 Video", WMV, taken with normal winds. Notice the bi-directional wind vein indicates little turbulence with winds from a single direction.

Here is "Rotating Wind Chime Part 2 of 2 Video", WMV, taken with very high winds. Notice the chimes tend not to rotate out of control with the high winds.

If you don't want the Mickey Mouse Ears, and probably most don't, simply hang the top support plate from a line and the very nature of the wind will catch enough of the chime tubes to rotate the entire set.

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Choice of Material for Wind Chime Tubes:
As I am sure many already know, the choice of metal makes a considerable difference in the timbre of the chime sound.

There are no bad sounding chimes when they are properly tuned and selected, just different in how they sound.

Say for example, two identical sets of chimes were built using exactly the same dimensions, one set from steel and one set from aluminum. They will sound vastly different. I selected aluminum and steel because they are at the opposite ends for density and elasticity. Steel has high elasticity and high density while aluminum has lower elasticity and lower-density. See chart to the right.

To confuse the issue even more, let’s say we properly build a 5-chime set of chimes using the C9 cord beginning with the C4 octave. One set from aluminum, 2” OD and 1/8” wall thickness, and one set from steel, 2” OD and 1/8” wall thickness. While each set will have different lengths, they will both strike the same note, but will again sound differently.

The steel set will have a longer sustain time (hang time) because it has more mass and can store more strike energy than the aluminum chime. Since the sustain time is different, the two sets will radiate the fundamental frequency and its overtones for different lengths of time, and sound quite different while striking the same note.

This does not make one metal good and another bad, they just sound differently. It's basically impossible to have a set of chimes for the same note range made from aluminum sound the same as a set made from steel because of the difference in density and elasticity.

Most often the choice is based on economics and weight. Your budget may not approve the cost of copper or brass, and aluminum may be more favorable than steel because of weight.

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Source of Tubing:
 Tubing sources seems to becoming more scarce at time goes on. Here are a few I found but I have no personal experience with them. I have had considerable success in locating brass and aluminum tubing at my local metals recycler.

Aluminum and brass tubing tend to exactly follow their stated ID and OD dimensions, however, copper tubing does not.
Wall thickness of copper pipe varies with the pipe schedule.
The four common schedules are named K (Thick-Walled), L (Medium-Walled), M (Thin-Wall),
and DWV (Drain/Waste/Vent - non-pressurized)
The printing on the pipe is color coded for identification;
K is Green, L is Blue, M is Red, and DWV is Yellow.
Both type "M" & type "L" can be found in home plumbing at Home Depot & Lowes.

Commonly available sizes for aluminum, copper, brass, steel and cast iron are in the DIY Wind Chime Calculator
 

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Measuring Tape:
I found it much easier to work in millimeters rather than inches. The problem was finding a tape measure that uses mm here in the USA. I found one made by The L.S. Starrett Company, model # CS1-8ME12. Lowe's Home Improvement carries the item but only at their web site. It cost about $10-. Another possibility is L.S. Starrett model # CH12-10DME

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Conclusions:
Clearly there is more to a chime than I had anticipated and I am sure I did not learn all that there is to know about the physics of a chime. This was a Christmas present project and not a focused research project. I am convinced that it is not necessary to hand tune a set of "bell-like" chimes designed for a musical notes from fundamental C2 through C4 because the formula achieved the desired frequency well within 1 Hz. Tuning to achieve an accuracy closer than 1 Hz was a waste of time. However, for a fundamental note from C5 and up, good tuning is required. BTW, good physical measurements are important to achieve the calculated accuracy.

My favorite design has changed over the years and is currently an end cap supported chime with the striker contacting the tube at the very bottom of the chime using a tapered striker, and having the wind rotate the chime set using a single line support for the support plate. Unfortunately, I know of no formula for calculating the length of a chime tube with an end cap. I begin with a length from standard calculations on this page and then tune by trimming off the length. End caps lower the frequency which requires removal of material to raise the tuning back to the correct vale. Yes, it's a lot of work.....!

On occasion I have just added an end cap to the calculated value for an open end tube in order to gain a more bell-like sound, but not adjusted the length to regain accurate tuning. For the most part, it has been difficult to acoustically tell the difference between the un-tuned chime set with an end caps and a set of tuned chimes with end caps. Perhaps I have been lucky or maybe the natural shift caused by the end cap is reasonably consistent for all five tubes, and they remain mostly in relative tune.

Your particular type of wind (single-direction or turbulent) and wind speed will determine the best choice for both the wind catcher and for the chime striker. Rotating the chime-set works well to solve the "Ding-Dong" sound caused from low velocity single directions winds.

Another phenomena that we observed, but did not have time to investigate, was the simultaneous sound from the natural bending mode of the chime coinciding with the resonance of the air column for the tube. The good news is that another engineer, Chuck at Chuck's Chimes, has done an excellent job detailing this effect  I suggest you give this a look-see. He has excellent information and calculations to accomplish this special effect.  https://sites.google.com/site/chuckchimes/home

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Calculations: Skip the math... If your looking for DIY calculations or pre-calculated dimensions, scroll down to here.

The bending natural frequency for a tube open at both ends is predicted by Euler's* equation. w = (B X l)2 X √ (E X I/(rho X l4))

If you want additional math on the subject here is a paper by Tom Irvine

I am not aware of calculations for a tube closed at one end. i.e. a chime with an end cap.

w - frequency radian per second  -  for frequency in cycles per second (Hz),  f = w/(2 X π)
E - modulus of elasticity
I - area moment of inertia = π X d³ X t/8 for a thin wall round tube
d - mean diameter
t - wall thickness
rho = mass per unit length = Area  X  mass per unit volume = π X d X t X density
l - length of tube

w= (B X l)² X (d/l²) X √ (1/8) X √ (E/density)

(B X l)²  - Constants based on the boundary conditions for a wind chime (Free-Free Beam)
(B X l)²  = 22.373 for the first natural frequency.
(B X l)²  = 61.7 for the second natural frequency.
(B X l²  = 121 for the third natural frequency.
(B X l)²  = 199.859 for the fourth natural frequency.

To get the units correct you must multiply the values inside the square root by gravity (g).
g = 386.4 in/sec² for these units.

For a given material then the frequency of a thin wall tube reduces to f = constant  X  d / l²

The formula reduces to:

Area Moment of Inertia = π X (OD^⁴ - ID^⁴)/64
                          Area = πX(OD^² - ID^²)/4
                              K = √((Elasticity X Moment X Gravity)/(Area X Density))
      Length (inches) = √(22.42 X K/(2 X π X f))

If you're curious about the circular mode (not considered here) see this http://paws.kettering.edu/~drussell/Demos/radiation/radiation.html

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Calculate your own Chime dimensions DIY
Requires any of the following to view and execute:
MS Excel Viewer (Free) Get it here; or Sun Open Office (Free) Get it here; or MS Excel (Cost $) Get it here;

Click to download or using right mouse, select "Save Target As" and save to a folder of your choice.

  DIY Wind Chime Calculator Base A=440 Hz in MS Excel (Traditional)

  DIY Wind Chime Calculator Base A=432 Hz in MS Excel (Old Original)

NOTE: Do not use these calculations for an orchestra or a musical setting unless you are certain they use A=440 Hz. An orchestra or symphony may brighten slightly and will typically tune for A=442 Hz, or 443 Hz, or 444 Hz. The above chart uses A = 440 Hz. Most symphony grade instruments are shipped with A=442 Hz

DIY Calculator includes the following features:

• Calculates length for tubes open at both ends or with end caps by using the "ratio calculator".

• Look-up tables for stand size tubing

• Look-up table for material properties

• Standard Music Scale

• All dimensions calculated are based on OD, ID in inches and Material type.

• OD = outside dimension of tubing (inches), ID = inside dimension of tubing (inches)

• Material type = Aluminum, Brass, Cast Iron, Copper, Steel, Stainless Steel & EMT

• Note selection by frequency in Hz

• The calculator uses nominal values for material properties; however, if you know the exact material density and the exact modulus of elasticity, you can enter that data for your specific material.

• The embedded Top Support Plate Calculator ask you to decide on the Chime Diameter (CD), the Striker Diameter (SD) and the clearance between the striker and the chime tube (D). The calculator provides the correct location for placing the chimes (R) and (CS), and the diameter of the support plate (PD). Instructions for use are included with the calculator.

• Read about cautions here

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Pre-calculated lengths for some common materials used in chimes are in the table below.
For sizes different than the pre-calculated tables use the DIY Excel sheet above.

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Suggested Reading

An interesting physics class, student project, authored by Professor G. William Baxter and Assistant Professor Keith M. Hagenbuch, both from Penn State, Erie

Thanks to the suggestion of a visitor (Larry) here is a book "The Physics of Musical Instruments by Neville H. Fletcher, Thomas D. Rossing" available at eBay HERE that has a great chapter on chimes and bells.
The missing fundamental effect
The missing fundamental (Hanover College)
Fletcher/Munson Curves   Fletcher/Munson Curves with ISO 

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Software:

  Wind Chime Designer by Greg Phillips Version 2.0

           Wind Chime Designer Instructions  PDF

If you have trouble unzipping Greg's new version here are the two files you need. Chime32A.exe and TUNING.DAT Using right mouse, select "Save Target As" and save to a folder of your choice. Place both files in the same folder and run the exe file.

Tune Lab Pro version 4 Good for frequency measurement only, not for musical notes from chimes

DL4YHF's Amateur Radio Software: Audio Spectrum Analyzer ("Spectrum Lab")
Good for fundamental frequency and overtone frequency measurement.

OscilloMeter Good for fundamental frequency and overtone frequency measurement.

Some good links:

Chuck's Chimes  Another engineer, Chuck, has an excellent web site for chime calculations and information. https://sites.google.com/site/chuckchimes/home

The Sound of Bells www.hibberts.co.uk/index.htm This site has not only nice pages on bell sounds and tuning but offers free software that lets you listen to the effects of overtones and allows you to tune your bell or chime using a sound card and microphone.

Bells and Their Music  www.msu.edu/~carillon/batmbook/index.htm Chapter 5: The Acoustics of Bells is a nice introduction to bell physics.

Pitch Perception  http://www.mmk.ei.tum.de/persons/ter/top/pitch.html Psychoacoustics of pitch perception.

The Strike Note of Bells   www.mmk.ei.tum.de/persons/ter/top/strikenote.html

* Equations from paper by Tom Irvine    Web Site   www.eng-tips.com/viewthread.cfm?qid=152064

Not exactly related but an interesting video Steam Driven Chimes   

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A Few Sources for Chimes

SQUIDOO

Windchimes by the inch  (Good source for supplies)

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FAQ's

Q Is there a length where a tube of a given size will not resonate as intended?  Specifically, I cut a tube of 1.5" thinwall
steel conduit to 1002mm, and it sounds higher in pitch than an adjacent 730 mm tube. I just can't wrap my head around this...:(
A Good question. The chime tube appears not to resonate but it is actually resonating. You discovered part of the "missing fundamental" phenomena. The 1002mm length has a fundamental resonance of about 193Hz and that frequency is hard to hear because of the low sensitivity of the ear at the lower freq (mostly below 300 Hz). Therefore you will hear the second overtone better which is 193 Hz x 2.76 = 523Hz. The fundamental for the 730mm chime is about 384Hz which is getting more into the sensitive range of the ear and you are much more likely to hear it's fundamental as compared to the fundamental for the 1002mm chime. Also see this.

Q Some chimes are anodized or appear to have a clear coat type finish for weather resistance or aesthetics I assume. Does a coating (powder coat, anodize or paint) affect the tone quality, tuning, or note sustain of the pipe?
A In general the answer is NO. However, if you were to paint it with a thick latex paint or some such coating, it would have a considerable affect. But a powder coat or anodizing will have little affect.

Q I have measured some different chimes and the hang point is usually close but far from exact. Should you drill the hang point hole at the center of the calculated measurement or is the hang point where the string actually contacts the tube (upper edge of the hole)?
A An excellent question. The answer is yes, the location of the hole should allow the string to touch the upper edge of the hole at the hang point. I drill just slightly below the mark to hang on the mark. With a small hole, there is enough flexibility in the location that even drilling on the mark won't seriously degrade the Q.

Q Does the hole size that you drill for the hang point matter?
A Yes, if it is large relative to the diameter of the tube it would affect the modes but a small hole has no affect. I personally use 1/8 inch or smaller.

Q I recently bought two not cheap wind chimes – and they do not chime in the absence of hurricane gale winds!!! Is there anything we (read – my husband) can do to get them to catch any breeze that happens by? Would the CD section in your article be all he needs? I have spent a long time on the internet looking for some quick fix but can’t find anything. The power company recently cut down all of the shrubs we have been carefully tending for years and now we have dreadful road noise. The chimes were an optimistic detraction to that new situation
A This is a typical problem in that the wind catcher is often too small and too heavy. Without seeing the set of chimes directly I might suggest you replace the wind catcher with something larger and lighter weight. I use an old CD just to make the point that it needs to be light weight and fairly large in size. Often an old CD is not large enough. You can use anything that pleases your eye and meets the size requirements, like a decorative aluminum pie pan or any such item.

Q Where do I get the mounting pins and what size is recommended?
A I typically use 1/8 inch brass pins and that stock is available at my local hobby store where a person can buy model airplane parts, model trains, model cars and the like. I have also seen 1/8 inch round stock at Home Depot.

Q How are they held in position in the tubes?
A If you put a 1/8 inch rod in a 1/8 inch hole it can be loose. I will take a hammer and slightly flatten one end of the pin for a force fit.

Q How does the string stay in the middle of pin and not slide off to the side?
A A spot of hot glue or epoxy will do the trick. A knot works well too. Click here to see a mechanical method

Q What type of string is recommended to hang the pipes?
A I have had good long term endurance with the nylon plumbing line from Home Depot and available in several colors. To reduce the UV effects I most often will dip the white nylon line in a dark wood stain to help reduce the deterioration over time. Nylon fishing line works well but be sure to deburr the mounting holes. For the heavy chimes I use 1/8 inch cable-pull nylon line used in the electronic data transmission business. I found an ample supply at a Hamfest one day. Not sure where to buy it over the counter. Might try an electrical supply store?

Q  I would like to know if it is possible to support a chime in a way that it is fixed, for example with a nail, without loosing its tune. I'm asking because I would like to build a music box. Also is it possible to fix it in a way that I wont need to drill a hole in it?
A  Yes, the chime can be structured for a fixed support using a number of methods. Any of the following methods should locate the support at 22.4% from both ends. An invasive method involves drilling small holes at the support locations and placing a nail or similar support through the hole. Exercise caution when using metal to metal since the contacting surface will tend to buzz when the chime is struck. The use of heat-shrink tubing or rubber mounts will solve that issue. See example at right. See advice from Travis Oberg below.

A noninvasive method is to use the traditional string method for supporting an orchestra grade chime bar. The chime can be located above or below the support string. See the picture to the left.

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Projects by site visitors click picture to expand

Aluminum & Copper wind chimes by Dan Shaw, Virginia, January, 2012
Swarovski crystals are used for the strikers while the hand carved Eagles are from sinker cypress. The Eagles are finished using Tung oil, white wood stain and mixed acrylic paint.
            

   Rustic cast iron water pipe chimes by David Balfour, June, 2011
 I made my striker and sail with small sections of the same wrought iron pipe (1.68" galvanized water pipe) and welded on hooks. I am keeping the finish natural (a bit rusty) but did coat it with WD40. The top leg support is made from a triangle of half inch steel with stubs that the legs slip on to. The top is an aluminum fry pan and it just sits on the to. I drilled holes into it to hold the chimes and striker. I chose the metal striker because after I had one strung up I really liked the clear tonal quality. I had some weed eater string (.060") that I used for chime support. They kind of sound like church bells. I didn't do any tuning except to measure the lengths. This was a fun project. I made it for my wife since she wanted a set of chimes.
 

A Chromatic Chime Set, By: Dan Larson Download Here pdf January, 2011

Why? Just because I could. I have friends who ring bells in church, and I am a closet piano player. When Pablo Casals played a Bach cello sonata VERY fast, someone asked him: why so fast? He answered: Because I can. My son named my creation C Machine, because it plays a C scale.

Read the entire account of this activity by Dan, very interesting....

 Tube Chimes by: Musician, Travis Oberg, California, www.travisoberg.com, May, 2010

Demo Song "White Stone" mp3, 7meg, 4:52, using the Tube Chimes

I chose 1" copper tubing and a chromatic scale C4 thru C5 (C4 was actually a test piece that I used and it's the only 3/4" pipe) and hung the pipes on a hardwood frame. Using the excel sheet as a guide I cut all pipe 1/16th long (as suggested) for fine tuning later. Using a hand file and a tuning device I tuned each pipe.

The most difficult was hanging the pipe without getting buzz. I chose a solid brass rod which I cut to length, and bought a drill bit that was essentially 'one sheet of paper' smaller than the diameter of the rod. Hammering the pins (cut from the rod) into the hole allowed a super snug fit; the copper gave way to the brass, fitting very tight. No buzz! That was the most tedious part, getting the hole to be drilled fairly straight and hammering each pin thru. I also built a sustain pedal to allow the chimes to ring a desired length. This wooden pedal bar pictured at the bottom is spring loaded. All in all the project was a weeks work and I am super satisfied with the result. Sounds good! Thank you!

Chimes by Stanley, Park City, Utah, April, 2010 - See his YouTube video here
Copper chimes using a cabinet knob as the striker and an aluminum electrical box cover for the wind catcher.

  Birdhouse Chimes, by James, April, 2010

  A cool father /daughter project

  Watch his video here wmv - 4 meg

Hip Chimes by John, Troy, NY, Jan, 2010
Tubular not, but none the less, they are chimes. Yes, these really are Chimes made from old orthopedic and dental implants that I have in my collection from 32 years, e.g., hip stems, knee prostheses, acetabular cup prostheses, dental blade-type implants, etc. Two of the hip stems are Ti (one is actually just a scrap piece from machining a hip stem) and the other 2 stems are Co-Cr-Mo alloy. When they are made out of Vitallium (a very hard Co-Cr-Mo alloy, usually cast, but sometimes wrought), the ringing is terrific. (Ti-6Al-4V alloy sometimes also rings pretty well.) (See the (Hip Chime Video Here) WMV

The middle clapper thing is an old-style Co-Cr-Mo acetabular cup replacement, which was meant to screw into the pelvis. The small rectangular plate above it is a little Ti plate, which will hopefully catch the wind a bit.

Medical Chimes by John, Troy, NY
Made from orthopedic (and dental) implants. This one has 2 knee joint pieces in it -- the portions that would attach to the end of one's femur. One is made from Vitallium and the other from Ti-6Al-4V alloy. Also one of the other hanging things is an implant-shaped "rasp" (used to prepare the femoral site for a hip stem). The 4th item is a porous-coated acetabular cup (with a little inverted nylon bolt passively running thru it, as a hanger to let it ring decently. (There's a small dental implant threaded into the shaft of the nylon bolt so I can hang the whole thing.) The striker is a large chunk of left-over titanium alloy, which was left from machining another part. The 2 flat wind-catching plates are pure titanium and Ti-6Al-4V alloy, left over from some cell culture experiments.

Chimes by Chuck, from Columbus, Ohio  Dec, 2009  Nice use of chains.
I made six set of chimes based on the information on your site and gave them away as Christmas presents. They sound great. Although, I'm not too sure about using the chain to support the ringer and wind catcher. It's probably much too heavy. See his Chime Video WMV

One bit of information you didn't explain is the need to create notes within the same chord in a given key. That way, any two or more notes that chime together will sound great together. My music teacher friend helped me select an F major 9th cord and a G major 9th cord.

Chimes by David from Alaska, Dec, 2009
The set is contains 20 chimes from 1-1/2" EMT (electrical metallic tubing) with a range from C4 to G above C5. The chimes are mounted in a frame of jacoba wood (sometimes called Brazilian Cherry). The frame construction is a combination of mortise/tenon and screwed connections.

I also found a given type of pipe has a limited range of notes that will ring well. I put a copper wire through the tube and through the last link of the chain. Then I used a long stick that just fit inside the bottom of the pipe with a point cut on the end in the middle. I pressed the stick against the copper wire to put a bend in the middle so the chain will center itself. It is much prettier, more heavy duty, and more permanent than string. Finding the brass chain was the most difficult part. I used Trex decking to make the top support and ringer so they will never decay.

Commissioned Chime Set by Kenny Schneider, 2003, 
 plays Bach's, "Joy of Man's Desiring" when struck.
 See https://artistsregister.com/artist_image.phtml?slideId=13395&backlink=artists&number=CO201

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The Biggest Intel® Chime Set

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An Engineering Approach to Wind Chime Design by Lee Hite
Loveland, Ohio, USA
Last updated on 01/30/2012
All Rights Reserved 1996-2012
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