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Frequently Asked Questions about Crafting Native American Flutes

This page provides answers to various frequently asked questions about crafting Native American flutes. It is mostly designed for beginning and novice makers of the instrument, providing starting points for your own experimentation into flute craft.

Long-time flute maker Ken Light in his shop in Montana

Long-time flute maker Ken Light in his shop in Montana Larger image

For frequently asked questions on the Native American flute in general, please see the General FAQ page.

A general note on the information on this page: There is no single, “best” way to do anything when it come to making Native American flutes. And there is no better tool than an open mind. Please use the information on this page as suggestions for starting points, and always take you own path when it presents itself.

Since I am not a flute maker, I have gleaned most of the information on this page from referenced sources as well as discussion on several on-line forums, in particular the Native Flute Woodworking and Basic NAFlute Making Yahoo newsgroups. I have also included some private messages related to flute crafting. All source that I have used are cited. In cases where I have used a complete answer posted in one of the newgroups, I have provided a by-line citing the author and location of the post.

Woodworking Safety: The information provided on this page offers guidelines on methods, collected from various sources, for crafting wind instruments. Please realize that these methods (and woodworking in general) can be a dangerous undertaking, possibly resulting in serious injury or even death. This page does not offer sufficient information to avoid those risks. When using this information for any purpose, I advise you to consult a qualified professional to verify the accuracy of the methods described and to take appropriate precautions and use proper procedures and safety equipment to mitigate those risks. I will not be held liable under any circumstance for direct, indirect, incidental, punitive, or consequential loss or damage or injury, due directly or indirectly to the use of this information provided on this page or on other pages on this web site.

This page (unlike the rest of Flutopedia) uses direct citations to external newsgroup postings, files, and photos. In particular:

If you would like to suggest a question that would be appropriate for this page, have a question and answer to propose, know of a message in one of the Yahoo newsgroups listed above that has been particularly helpful, have additional information on flute crafting that might be appropriate for this page, or feel that an error has been made or have suggestions on improving this FAQ, please contact me with as many of the specifics as possible.

If you need information beyond what is provided on this page … please realize that I do not actively craft flutes and cannot address individual flute-making issues with any authority. However, there are two excellent forums for such discussion. I would strongly suggest that you join one (or both) of these Yahoo newsgroups — they have a combined history of 26 years and over 75,000 messages (!!):
 
Native Flute Woodworking Yahoo Newsgroup
 
Basic NAFlute Making Yahoo Newsgroup

Questions that begin with “…” are follow-on questions that relate to the question before them. For example:

… this is a follow-on question that relates to the prior question and answer

One more thing: please realize that some of these questions lead to rabbit hole topics. Questions that appear to be a straightforward lead to answers that get progressively more murky, with caveats, special cases, and historical issues popping up that take you farther and farther from what you hoped would be a straightforward answer.

Table of Contents

Here are links to the major sections of this FAQ:


Background Topics

What are the common design elements of a Native American flute?

A Native American flute is a flute that is held in front of the player, has open finger holes, and has two chambers: one for collecting the breath of the player and one which is designed to resonate and create sound. The two chambers, called the “slow air chamber” and the “sound chamber”, are separated by a “plug”. Air is directed from the slow air chamber to the sound chamber by a channel called a “flue”. The flue is formed by a combination of the body of the plug, the body of the flute, and an external “block”. The phrase “open finger holes” means that the finger holes on the instrument are closed by your fingers, rather than keys or mechanical mechanisms.

External and internal elements of a Native American flute

External and internal elements of a Native American flute Larger image

This description is based on the definition provided by R. Carlos Nakai on June 21, 2002 as “A front-held, open-holed whistle, with an external block and an internal wall that separates a mouth chamber from a resonating chamber.

There are a few elements shown in the diagram above that are not central to the design of the instrument: the strap is optional and the nest and breath hole have many configurations in various designs of the instrument. Also note the things that are not mentioned: there is no specified number of finger holes, spacing between the holes, or shape of the various components.

For more information, see the Native American Flute Anatomy page on this site.

 

What are the primary approaches to crafting the body of a Native American flute?

One of the main considerations in crafting a Native American flute is how to create the hollow interior chambers of the instrument. Here are three general strategies:

  • Natural bore. If you use a material that has a naturally hollow bore, a great deal of work has already been done for you! Bamboo, river cane, and yucca stalks are common materials with natural bores. Also, woods that have a soft pith in the center can be used.
  • Drilled bore. Augering a hole lengthwise down a blank of wood can be done to create the slow air chamber and the sound chamber. Some makers use lathes and drill bits designed for creating gun bores.
  • Split / routed bore. Take a solid block of material, split it in half, remove material in each half, and bind the two halves back together. There are many variations on how the wood is split (band saw, chisel in creating a branch flute), how the material is removed (power or hand router, scorp chisel), and how the halves are re-joined (various glues and external binding or sealing systems).

How are the finger holes numbered?

You are likely to encounter two different numbering conventions for the finger holes, depending on whether you are talking to a flute player or a flute maker, they are numbered differently:

Numbering the holes on a Native American flute

Numbering the holes on a Native American flute Larger image

Why this difference?

  • When a flute maker works on the finger holes of the flute to tune them, they begin with the holes nearest the foot end of the flute. So “flute maker hole #1” is at the foot end of the flute.
  • Flute players looking down at their fingers see “flute player hole #1” first.

Most of this web site uses the Flute Player Numbering convention. However, on this page I will explicitly describe the location of the hole based on whether it is near the head end or the foot end of the flute.

Are there alternate names for the parts of a flute?

Yes! Here is a diagram with all the alternate names I have encountered. The names that I prefer to use on Flutopedia are shown in green, with the alternate names in blue. Click on the image for an larger version:

Alternate names for Native American flute components

Alternate names for Native American flute components Larger image

What materials should I use?

Flute makers have used a huge variety of materials to construct the body of flutes: wood, metal, bone, bamboo, reed, plastic (PVC and ABS), glass, and I'm sure I'm missing some.

Most Native American flutes have traditionally been and are currently crafted of wood.

Which wood should I use?

The main issues of wood selection surround the species of wood — which primarily determines the density, grain pattern, toxicity, workability, suitability for gluing, etc — and the characteristics of the particular sample of wood — primarily the cut, moisture content, and straightness. Of course, there are real-world considerations of availability and cost.

The vast topic of wood attributes is beyond the scope of this web site. However, there is an excellent, authoritative, and detailed reference freely available from the Forest Products Laboratory of the U.S. Department of Agriculture Forest Service: [Bergman 2010] Wood Handbook — Wood as an Engineering Material, Centennial Edition. You can also browse the many discussions and recommendations on the Native Flute Woodworking and Basic NAFlute Making Yahoo newsgroups.

 


Basic Construction Parameters

What is the recommended diameter for the sound chamber?

The diameter of the sound chamber (also called the “bore” among flute makers) depends on the key of flute you are making. When starting out as a flute maker, it is best to keep the bore diameter within a certain range.

Here is a table of recommended bore diameters from three published sources: [Stanford 2008], page 11, [Wolf 2001], page 19, and [Wolf 2004]. The recommendations all use the 18″ steps typically available for router bits.

These recommendations can provide a good starting point. For a more in-depth analysis, including measurements from survey of 61 actual Native American flutes, see Native American Flute Bore Diameters.

Bore Diameters from Published Recommendations
Range Key Stanford 2008 Wolf 2001 Wolf 2004
High / Alto E5     38
D#5 / Eb5     12
D5 12 12 12
C#5 / Db5 12 58 58
C5 12″ or 58 58 58
Mid-Range /
Medium /
Tenor
B4 58 34 58
A#4 / Bb4 58 34 34
A4 34 34 34
G#4 / Ab4 34 34 34
G4 34″ or 78 34 34
F#4 / Gb4 78 78 78
F4 78 78 78
E4 1″ 1″ 1″
D#4 / Eb4 1″ 1 18 1 18
D4 1″ or 1 18 1 18 1 18
C#4 / Db4 1 18 1 14 1 14
C4 1 18 1 14 1 14
Low /
Baritone
B3 1 14 1 14 1 12
A#3 / Bb3 1 14 1 14 1 12
A3 1 14 1 14 1 12

Notes:

  • The Range is from the Flute Keys page on this site.
  • Using a smaller bore diameter than indicated will tend to produce a flute that overblows more easily. Using a larger bore than indicated tends to make the flute less easy to overblow, and reduces access to the upper-register notes. See the next question …

What are the effects of bore length and the bore diameter on flute design?

The ratio of the length to the diameter of the sound chamber has a dramatic effect on the playing characteristics of any wind instrument. Flute makers typically call the diameter of the bore (which forms the sound chamber) “D”. The length of the sound chamber that is called “L”. However, this length is really the acoustic length of the sound chamber — a number close to, but not exactly, the physical length of the sound chamber. (For more on acoustic length, see Acoustic Length of a Flute.)

The ratio L:D is called the sound chamber aspect ratio of the flute. For example: 18.6:1 is a typical ratio. It is often expressed as a single number by calculating L/D … for example: 18.6.

Native American flutes tend to have lower sound chamber aspect ratios (i.e. fatter sound chambers for their length) than other wind instrument designs … typically in the range of 12 to 22. A sound chamber aspect ratio of 18 is typically quoted as a good starting point in for novice flute makers. In contrast, the Western concert flute has a sound chamber aspect ratio of about 38 and the fujara, an ethnic wind instrument from Slovakia, typically has a sound chamber aspect ratio of about 55.

Generally speaking, here are some effects of the sound chamber aspect ratio:

  • Higher aspect ratios allow for higher registers to be reached by the instrument, increasing the overall range of notes that can be played by the instrument.
  • Wind instruments with higher sound chamber aspect ratios typically produce higher overtone frequencies in their first register, producing a timbre that many listeners say is “brighter”.
  • Instruments with higher sound chamber aspect ratios tend to overblow into the second register more easily.

What is the recommended length of the sound hole?

The predominant recommendation as a starting point for the length of the sound hole (measured along the long axis of the flute) in discussions on the Yahoo/NFW and Yahoo/BNAFM newsgroups is 732″ for a mid-range flute. This recommendation is also made in [Stanford 2008], page 28 as well as in [Price 2010] How I Make Flutes Today, excerpted here:

The sound mechanism is the most critical part of any flute. I use small rasps and small files to properly configure the channel, the true sound hole, and the splitting edge. The channel must be such as to allow smooth airflow (very little turbulence). The dimension of the true sound hole that is parallel to the length of the flute body is extremely important, and with most sound mechanisms should be precisely 732 inch. If this dimension is exceeded, the flute begins to lose its clear sound (begins to become breathy). If this dimension is reduced, the flute begins to lose volume of sound and sometimes suffers from “nodal interference” …. If one wants to have a breathy sound from a flute, there are many ways to set a flute to make it so, but there is no way to set a breathy flute to make it clear sounding. It is best to start with the clear sound when the flute is being created.

However, Mike Prairie (Yahoo/NFW, #56,324, March 24, 2014) notes that:

The optimum TSH (sound hole) length and flue depth will vary with the key of the flute, among other things. I wouldn't expect a high D flute to have a TSH as long as 7/32, nor would I expect a bass A to have one so short. What I have found to be “optimum” for me is based on the ratio of the TSH length to the flue depth; I tend to favor something around 6:1, while others tend toward 7:1 (a typical recorder has a 4:1 ratio). For a 7/32 TSH in a mid-range flute, I might have a flue that was about 0.035 (1.12/32) for a 6.25:1 ratio, while a 1/32-deep flue for the same TSH would be right on the 7:1 mark. Try different things and you might find that voice you're hunting — just be sure to be precise in crafting your sound mechanism since rough surfaces and non-symmetric shapes will cause more problems than you might expect.

See the Flute Crafting Dimensions page for more information on the key dimensions for constructing flutes.

What is the recommended width of the sound hole and the flue?

The predominant recommendation as a starting point for the width of the sound hole and flue in discussions on the Yahoo/NFW and Yahoo/BNAFM newsgroups is 50% of the diameter of the bore of the flute (i.e. half the width of the sound chamber). See, for example, Joe Nulph, Yahoo/BNAFM, #18,004, July 29, 2013. This recommendation is also made in [Stanford 2008], page 14.

For example, if the bore has a diameter of 34″ (typical for flutes with fundamental notes of G4, G#4, and A4), then the recommended sound hole and flue width is 38″.

Edward Kort (Yahoo/NFW, #56,009, December 23, 2014) prefers a wider sound hole and flue. He typically sets the width of his sound hole and flue in the range of 62–67% of the bore diameter.

See the Flute Crafting Dimensions page for more information on the key dimensions for constructing flutes.

What is the recommended depth of the flue?

Mike Prairie has calculated (Yahoo/NFW, document: TSH length vs. flue depth.pdf, posted in the “For Beginners” directory of the files section on January 1, 2007) that, a flue depth that is 20% of the length of the sound hole (measured along the long axis of the flute) results in “maximum efficiency”. For example, with a sound hole length of 732″, a flue depth of 364″ (or a shade under) is ideal. However, he also notes that other variables will affect the ideal ratio, so the 20% factor should be considered a good starting point.

See the Flute Crafting Dimensions page for more information on the key dimensions for constructing flutes.

What is the recommended length of the flue?

Mike Prairie (Yahoo/NFW, #57,470, June 20, 2015) provided the opinion:

The flue … shapes the profile of the jet [of air] as it emerges into the TSH. A short flue will have a flatter profile—meaning that the velocity across the jet from top to bottom will be flatter across the center, while a long flue will have more of a bell-shaped profile. This is because of a thing called the “boundary layer” that essentially slows the air between the main flow in the flue and the flue floor and the bottom of the bird. The air from the SAC enters the flue with a velocity profile that is flat (same velocity across the flue height), but the velocity at the top and bottom surfaces along the flue must be zero. The boundary layer is the transition between zero velocity at the surface and full velocity in the center, and it grows as the air progresses along the flue (the boundary layer remains laminar—no turbulence—if the walls are smooth). If the flue is long enough, the two boundary layers will meet in the middle, resulting in what is called “fully developed flow” that results in a bell-shaped velocity profile. I once estimated that in a “typical” flute the length for this to happen is between about one and two inches. If the flue is shorter, the boundary layers will not meet and the center profile will remain flat, and the shorter the flue, the flatter the jet.
 
When the jet leaves the flue it will begin to expand as it moves across the TSH, and the shape of the velocity profile will spread as well, but the jet with the flatter profile will hold together a little better by the time it reaches the cutting edge. The jet motion oscillates up and down, so think of the split air that flows under the edge as the driving force on the air column. If the jet profile was perfectly flat, the driving force would be a pure sine wave (no harmonics), but since the shape of the jet is not flat, the driving force will result in a distorted sine wave. The distortion in the driving force is what generates the harmonics, and depending on the shape of the jet as it hits the cutting edge, the relative strengths of the harmonics generated will be different.
 
The bottom line is a longer flue will therefore generate a different harmonic spectrum than a short flue.

See the Flute Crafting Dimensions page for more information on the key dimensions for constructing flutes.

What is the recommended length of the sound chamber?

Using the measurements and guidelines discussed so far in this Basic Parameters section, we can look at some example flute designs.

The table below shows a few example design variations for the most common mid-range Native American flutes. The calculated total bore length and L:D ratio come from the NAFlutomat tool (using defaults for all parameters that are not explicitly shown in the chart below). There are some simplifying assumptions in these designs:

  • The bore is round and limited to round-nose router bit sizes that are typically available.
  • Playing and tuning conditions are 72°F and 45% humidity (these values affect the speed of sound).
  • The flute has no direction holes.
  • Only designs with a L:D ratio in the range of approximately 16–20 are provided.

To create flute designs beyond these basic examples, see the NAFlutomat tool.

Example Flute Designs for mid-range Native American flutes
Key Bore diameter Sound hole Flue NAflutomat output
length width depth Bore Length L:D
A4 34 732 38 364 13.114″ 17.55
G#4 / Ab4 34 732 38 364 14.033″ 18.77
G4 34 732 38 364 15.006″ 20.07
78 732 716 364 14.536″ 16.65
F#4 / Gb4 78 732 716 364 15.568″ 17.83
F4 78 732 716 364 16.660″ 19.08
1″ 732 12 364 16.162″ 16.19
E4 1″ 732 12 364 17.319″ 17.35

What is the recommended length of the slow air chamber?

Vance Pennington (Waking Spirit) provided a detailed opinion on this issue (Yahoo/NFW, #16,253, August 24, 2004):

Slow Air Chambers are ideally as large as possible. I create all of my mid-range flutes with a 5 inch long SAC by whatever the bore is I am using for the flute. As another member of this group has stated, some makers create their flutes with a SAC at a length that makes the flute look good as, after all, the length of the SAC will determine where the bridge is situated. A flute with a SAC that is really long will result in a flute that looks as though the block is in the middle of the flute. It probably will play well but it sure doesn't look too good!
 
This is where flute design comes in because their are two other major factors which have to be considered when creating an instrument. One is how well the flute looks and the other being the 'balance' of the flute. An instrument that is top heavy at either end is cumbersome to play!
 
The longer the SAC the better the flute will play. With a SAC of 5 inches plus the blow hole length (for shaping purposes) of around 2.5 inches the length between the blow hole entrance and the bridge (plug) will total 7.5 inches. To compensate for this I create a longer sound chamber, adjusting my tuning and playing holes to compensate for this. Part of this 'compensation' includes assuring that when the flute is held between the finger and thumb at the very top hole position (nearest the bridge) the flute will balance perfectly.
 
Variations to this (but not the balancing factor) are high-range flutes and low-range flutes. High range flutes (say high C minor) have a smaller bore size and need to be shorter in length. This will result in a smaller SAC but this has an advantage. Higher frequency notes in a NAF are more difficult to produce at the same breath pressure as a mid range flute. The shorter SAC allows for this slight increase in pressure.
 
Low frequency notes, such as on a Low C (Bass) flute, however, require the opposite. Low range frequencies vibrate at a very slow rate and are easily distorted or destroyed by too much breath pressure. The problem here arises with the overall size of the flute and the reach required to play the fingering holes. A smaller SAC (say around 3 inches) makes the flute's fingering holes easier to reach. But, of course, ideally the SAC should be much longer. Experienced flute players compensate for this by simply blowing more gently into a bass flute than they would a mid-range or high-range flute.
 
So, there are several factors involved in answering this. Measurements depend on the size and style of bridge you use and the size of the block. The best way to advise you is to say that you should ideally make your SAC longer than 3 inches. The longer you can make it the less pressure will result.Your blow hole size and length depends on the style of mouth piece you create, be it a tapered end, a nipple end or something else. My advice is to make it as wide as practicable and as long as possible as this will also help reduce pressure. The exit hole from the SAC to the bridge should also be as large as possible but this size is restricted again by the bridge size you use and the block size.

 


Acoustics and Flute Dimensions

This section of questions develops the link between the physical dimensions of a flute and the pitches that we hear. Unfortunately, this is not a straightforward topic and my approach will only suit a small portion of the flute-maker community.

Please don't be put off by the complexity of this topic. An understanding of how the dimensions of the sound chamber relate to the flute's pitch is central to many aspect of flute making. However, if you find yourself bogged down in the details, just put it aside, play your flutes for a while, and come back to it from time to time. Also, surf around the web for other versions and approaches to this topic.

What is acoustic length?

Acoustic length is the length of the resonating column of air inside the sound chamber of a flute. The acoustic length determines the pitch or frequency of the note that is produced. The acoustic length is the effective length of the sound chamber of a flute when the fundamental note is played.

The acoustic length is typically longer than the physical bore length of the sound chamber (measured from the plug to the foot), because of acoustic effects that take place at the foot end and at the sound hole of the flute. These effects can be calculated by formulas for end corrections. Adding the end corrections to the physical bore length of the sound chamber gives you the (theoretical) acoustic length for the flute.

See Acoustic Length of a Flute for a full description of this phenomenon, including detailed calculations.

Acoustic Length = Physical Bore Length + End Corrections

Acoustic Length = Physical Bore Length + End Corrections Larger image

What are end corrections (k1 and k2)?

End corrections are calculated lengths caused by openings in a sound chamber, such as open finger holes, the sound hole, direction holes, or the end of the chamber. When you add all the end corrections of a sound chamber to the physical bore length of that sound chamber, you get the acoustic length.

It is customary to denote the end correction at the foot end of the flute as k1 and the end correction at the sound hole as k2.

See Acoustic Length of a Flute for a full description of this phenomenon, including detailed calculations.

How does acoustic length relate to the sound produced?

The acoustic length of the sound chamber directly determines the physical length of the air pressure wave produced. Specifically, the wavelength of the air pressure wave is twice as long as the acoustic length of the sound chamber that produced it.

How does wavelength relate to the frequency of the note produced?

We perceive the frequency of a sound based on how frequently our eardums are moved each second by changes in air pressure. If the air pressure changes at a steady 200 times per second (or 200 Hertz), our brain's auditory system hears a 200 Hertz frequency.

Higher frequencies sound like higher pitched notes to our ear. In particular if you double the frequency, you will hear a note that we call one octave higher.

If you hit a drum head, it vibrates for a short time based on its physical characteristics such as its material and how tightly it is stretched. If it vibrates at 200 Hertz, it creates an air pressure wave at 200 Hertz which travels through the air and pushes on our eardrums at 200 Hertz. However, the tone is not sustained since the drum head vibration stops quickly.

If you draw a bow across a violin string, it vibrates and creates an air pressure wave like the drum head. The frequency of the vibration is based on the length of the string and how tightly it is stretched across the violin. Unlike the drum head, the tone produced is sustained as long as the bow continues to cause the string to vibrate.

The sustained tone produced by a flute is similar to a violin. However, since the acoustic length of the sound chamber is typically fixed, the wavelength of the tone is likewise fixed (to twice the acoustic length). The frequency we hear is controlled by both the length of the air pressure wave (i.e. the wavelength) and how fast that air pressure wave arrives at our eardrum.

How fast does an air pressure wave travel?

It travels at the speed of sound, which is affected by air temperature and, to a much lesser degree, humidity.

How do you calculate the frequency from the acoustic length of a flute?

In addition to the acoustic length, you need to know the speed of sound.

In dry air at 68°F, sound travels at about 343 meters, 1,125 feet, or 13,500 inches each second. That is about 767 miles per hour or about a mile in five seconds.

The formula for frequency from acoustic length is:

frequency = speed of sound / wavelength

frequency = speed of sound / (acoustic length × 2)

For example, take a flute with a physical bore length of 17.50″ with end corrections of k1=0.50″ and k2=0.25″. This gives an acoustic length of 18.25″. Doubling the acoustic length give us the physical length of one cycle the air pressure wave created by the flute: 36.50″. Applying the formula:

frequency (cycles per second) = speed of sound (inches per second) / wavelength (inches per cycle)

frequency (cycles per second) = 13,500 (inches per second) / 36.50 (inches per cycle)

frequency = 369.86 cycles per second (Hertz)

So our example flute produces a frequency of 369.86 Hertz.

What are pitches?

Rather than dealing with frequencies, musicians use a shorthand notation of pitches.

In most music traditions, the pitches are divided into octaves. The octaves are numbered, with octave number 4 being a mid-range. See Octave Notation for details of octave numbering.

The frequencies in one octave are exactly double the frequencies in the next lower octave, and exactly half the frequencies in the next higher octave. In the Western music tradition there are 12 pitches within each octave. They are named C, C# (same as Db), D, D# (same as Eb), E, F, F# (same as Gb), G, G# (same as Ab), A, A# (same as Bb), and B.

A note in the Western music tradition is often followed by the octave number as a subscript. For example: C3 and G#5.

How does frequency relate to pitch?

In order to convert frequencies to pitches, we need two things:

  • a pitch standard or “standard pitch”, which fixes one pitch to a frequency, and
  • a tuning system, which is a rule that tells us how to calculate the frequencies of all the other notes.

There have been many pitch standards over the years, and the use of pitch standards is a major rabbit hole topic. One very prevalent standard is to assign the note A4 to the frequency 440 Hertz. This is often written as A4=440 or simply A440.

The various rules for tuning systems and musical temperaments are also a major rabbit hole topic. One very common musical temperament is called equal tempered tuning (or “equal temperament”), which places each note so that the ratio of frequencies between neighboring notes is the same. Equal temperament has various benefits and shortcomings, which will not be addressed in this FAQ, lest I fall down the rabbit hole and pop out in an alternate universe.

If you use equal temperament and A4=440, you can translate each frequency to a pitch. A table is provided on the Flute Keys pages on this site.

Continuing the example from above, we calculated that our flute would produce a frequency of 369.86 Hertz. Looking at the Flute Keys page, this translates to a shade lower (flatter) than a pitch of F#4.

 


Workshop at the Brussles Music Instrument Museum, Clint Goss, February 23, 2010

Workshop at the Brussles Music Instrument Museum
Clint Goss, February 23, 2010 Larger image

Tools

This sections provides some ideas on useful tools and jigs that can help in flute crafting.

What jigs are used by flute makers to craft flutes?

Here are some jigs that I have come across that can improve the safety and precision of flute crafting:



Sealing the Inside of the Flute

This section has thoughts and ideas on sealing the inside slow air chamber and sound chamber of the flute.

However, please note that, while sealing protects the wood from moisture, it is not a requirement to seal the bore or slow air chamber of the flute.

Shellac

However, Mike Prairie (Yahoo/NFW, #56,517, June 9, 2014) provided his experience with sealing flutes using shellac:

An old favorite is shellac. You can get it pre-mixed at any decent hardware store. You can also mix up your own if you order the dry flakes and mix with denatured alcohol and control the “cut,” or viscosity. The “full strength” stuff you get at the hardware store is a 4-pound cut (4 pounds of solid shellac to a gallon of denatured alcohol), but you can thin it to get a lighter cut. A one-pound cut is good as a sanding sealer, and because it is alcohol-based, it dries almost instantly if applied in thin coats. I have often used a 2-pound cut (50/50 denatured alcohol mixed with full strength premixed shel lac) for sealing the bore initially to get good penetration and quick dry time, followed by 4-pound shellac for subsequent coats if I am going for a glassy-smooth bore.
 
Some folks have made dipping tanks with PVC pipe, and dip their flutes and let them soak up the finish before pulling them out and hanging them to dry. I like to use tung oil as the first external coat to pop the grain (then seal that with shellac after it has cured), so I don't dip. (I used processed stuff in Formby's tung oil—natural tung oil takes forever plus a long time to fully cure …). Instead of dipping, before drilling finger holes are drilled or burned, I will seal up the sound hole and pour shellac into the bore. I swish it around and dump it, and then give it a quick wipe with a rag dampened with denatured alcohol to keep drips from forming. Any leaking onto the outer bore is wiped off, and the remaining shellac is removed with the final sanding to get ready for the oil.
 
Once the first coat is dry, I sand the bore with fine sandpaper, and repeat the process. My sanding is done with a rod chucked into a drill, and the end of the rod has duct tape spooled on it to build it up to just under the bore diameter. I tape enough sandpaper on to the tail of the duct tape so that when it makes the final wrap it just fits inside the bore. My last step is usually to polish the bore with 0000 steel wool on the end of a gun cleaning rod, but for a really glassy bore, I'll wax it (carnuba wax that cured hard) and burnish it with a paper towel taped to and wrapped around a rod.

Another approach to avoiding problems gluing halves of a flute that have been sealed …

Instead of taping off the areas to be glued, I cut my blanks a little bit thicker before beginning construction by 18″ or so. Then when routing the slow air chamber and main tube I increase the depth of cut by the same amount. For example, a 12″ radius core box bit would be set to cut a 58″ depth channel. After sanding, I then sealed and finished the interior without masking. After the finish dries completely, I then rip the blanks on the table saw, removing the extra 18″ thickness with a high quality saw blade, leaving perfect gluing surfaces without the need to mask the blank. (A big time saver, and a neater gluing edge).

— Carl Gilbert, personal communication, July 28, 2014


Locating the Finger Holes

Where do I position the finger holes?

There are many, many approaches to finger hole placement and tuning. You could:

  • place them randomly,
  • place them according to some rule,
  • copy another flute,
  • use an existing set of plans, or
  • try to predict the best placement based on an intended scale of notes and/or acoustic properties.

It is typically the last general approach that causes the most angst among flute makers, since it often involves many choices and calculations.

As a starting point, the Finger Hole Placement page on this site offers various approaches and general rules for placing the finger holes.

If you would like to use some published plans, visit the Plans for Flute Making on this site. There is also the Flute Sheet Excel spreadsheet that is available for download.

There are also a number of How-To Manuals available that specify how to locate the finger holes.

If you would like to embark on your own design, this generally involves several steps:

  1. Choose a flute tuning or scale. An overview of some of the possible tuning and scales is provide on the Native American Flute Tunings page, and an extensive map of potential tunings is provided on the Flute Tuning Map page.
  2. Use some calculation method to predict good starting locations for your finger holes. You could copy and existing flute of the same flute tuning, possibly scaling the finger hold locations to suit the key of flute you are making. If you are making a pentatonic minor mode 1/4 flute, you can use the NAFlutomat tool on-line calculator on this site.
  3. Drill your hole locations using relatively small holes, and then gradually increase their size to bring them into the tuning you want.

How large should the finger hole be?

If you intend to tune a flute to a particular scale, the size of the finger holes is closely tied to the (lengthwise) location of the finger holes on the sound chamber of the flute:

Design. Most flute makers design a flute considering both the location and size of finger holes. The issues include aesthetics, playability, the tuning of cross-fingered notes, tone quality, and the ability to play notes in the second register.

Construction. During construction, the finger holes are usually created to be smaller than their intended size. This will initially make the pitches of their notes flatter than intended.

Tuning. During the tuning phase, the flute maker will gradually make the finger holes larger until they produce the desired pitches.

See the page on Finger Hole Size for a discussion of these considerations.

What can I do to make it easier for players to reach and cover the finger holes?

There are many considerations related to reaching the finger: spread between fingers on the same hand, distance from the mouth to the upper and lower hands, size and shape of the finger hole itself.

A typical mid-range flute might have finger holes spaced to look something like this:

Finger hole layout in a typical mid-range six-hole Native American flute

Finger hole layout in a typical mid-range six-hole Native American flute. Finger layout 123-123 Larger image

The dimensions of images in this section are based on results from version 1.27.2e of the NAFlutomat tool on-line calculator for a mid-range F#4 flute using default parameters for all inputs to the calculator. In particular, the bore diameter was set to 78″ (0.875″) with a 316″ (0.1875″) wall thickness at all finger holes. The finger hole locations and dimensions of the bore are to-scale. However, in the interest of clarity in these diagrams, the finger holes are shown substantially larger (40–50%) than those specified for the NAFlutomat calculations.

In the typical six-hole arrangement above, the two groups of three finger holes are covered by the index finger, middle finger, and ring finger of each hand. I call this finger layout “123-123” (see the Finger Layout page for a complete description of this terminology).

As the key of the flute gets lower, the holes become spaced proportionally further apart. This creates a problem for players since one hand has to span the upper three holes and the other hand has to span the lower three holes. To accommodate this limitation, flute makers tend to cluster the upper three holes and also the lower three holes. Here is an exaggerated example of the result:

Finger hole layout with “clustered” groups of holes to accommodate the player's hand span

Finger hole layout with “clustered” groups of holes to accommodate the player's hand span Larger image

In each group of three holes, the hole nearest the head end moves toward the foot and the hole nearest the foot end moves toward the head. However, the sizes of the holes have to change to bring those notes into tune. There are several effect of having finger holes of drastically different sizes on a flute:

  • The tonality of notes across the scale changes noticeably from note to note.
  • The tuning of cross-fingered notes is affected, often to the point where it is not possible to achieve one or more cross-fingered notes without using half-hole techniques.
  • The very large finger holes may be difficult for the player to seal during normal play.

To avoid these issues, some flute makers offset some of the finger holes from the centerline of the instrument. Here is a typical arrangement:

Offset finger holes on a right-handed flute

Offset finger holes on a right-handed flute Larger image

Note that offsetting a finger hole by rotating it around to a different position on the bore does not affect the pitch produced. The finger hole nearest the foot of the flute in each group of three — the finger hole corresponding to the “ring” finger on each hand — is typically the hole that is offset.

However, this strategy does have one potential downside: only players that are comfortable with a particular “handedness” can play the flute. The flute in the diagram above will only be comfortable for a player that is used to a “right hand on the bottom” orientation.

Here is a flute showing offset finger holes as they would be arranged for a player who uses the “left hand on the bottom” orientation. (This is a flute crafted by Trent R. Logan, and I have reversed the photograph from his original to demonstrate this orientation):

Flute by Trent R. Logan showing offset finger holes designed for a “left hand on the bottom” orientation

Flute by Trent R. Logan showing offset finger holes designed for a “left hand on the bottom” orientation Larger image

Other things you can do to keep the finger holes at the same station (location along the length of the sound chamber) and avoid changing the sizes of finger holes (these ideas were suggested by Edward Kort, personal communication, August 23, 2014):

  • Since the tuning of a finger hole is based on where the hole is on the inside of the sound chamber, you can angle the finger hole (up to 45°).
  • Use bore perturbations to regulate hole spacing. [This is a complex topic and beyond the scope of issues covered in this FAQ. See discussions on the Yahoo newsgroups mentioned above for a wealth of information about bore perturbations.]

As flutes get lower in pitch, the strategy of offsetting finger holes needs to be taken further to keep the finger holes within reach. The finger layout below is a modification of a five-hole flute layout that is often used on Japanese shakuhachi flutes:

Finger hole layout T14-13

Finger hole layout T14-13 Larger image

The top hole has rotated 180° to the back of the flute and become a thumb hole. The second finger hole from the head of the flute is now covered by the index finger. The next finger hole, typically covered by the index finger of the lower hand, is now covered by the ring finger or pinky of the upper hand. The bottom two holes are covered by the index finger and the ring finger of the lower hand. I call this arrangement T14-13.

Here is an example of a T14-13 arrangement on a flute by Zacciah Blackburn (the thumb hole is not visible):

Zacciah Blackburn low Bb3 flute with finger hole layout T14-13

Zacciah Blackburn low Bb3 flute with finger hole layout T14-13 Larger image

... and here is the same flute in my hands. (But note that I do not actually play the flute like this — I am holding my hands away from the body of the flute to demonstrate the finger holes):

Zacciah Blackburn low Bb3 flute with finger hole layout T14-13

Zacciah Blackburn low Bb3 flute with finger hole layout T14-13 Larger image

I have flutes using the T14-13 finger hole layout shown above that go down to a fundamental of G3 and E3 (both crafted by Bill Hughes).

To go even lower, Romy Benton uses an innovative T2-T2 arrangement:

Finger hole layout T2-T2 for very low flutes

Finger hole layout T2-T2 for very low flutes Larger image

Since this finger layout only has four finger holes, the player needs to overblow in order to get the octave note.

Here is a photo of my holding a Romy Benton Eb3 flute. Again, I do not actually play the flute like this — I am holding my hands away from the body of the flute to demonstrate the finger holes:

Zacciah Blackburn low Bb3 flute with finger hole layout T14-13

Romy Benton low Eb3 flute with finger hole layout T2-T2 Larger image


Tuning

How do I tune the flute?

You begin with small finger holes placed in the locations that you have determined by one of the methods described in the "Where do I position the finger holes?" question above. You then gradually make them larger until they come into tune with the pitches you want.

Flutopedia has three tuning methods. The first two are relatively basic, and should probably be attempted first if you are a novice flute maker. The third method coaches you on how to bring all the cross-fingered notes into tune in addition to the primary notes:

What is “undercutting”?

Sometimes when a flute maker is tuning a particular finger hole, they need to remove material but do not wish to make the surface of the finger hole physically larger. If the hole gets too large on the external surface of the instrument, the player might have a difficult time covering the hole.

Cut-away image of an undercut finger hole

Cut-away image of an undercut finger hole Larger image

Undercutting is a technique of removing material from a finger hole underneath the external surface of the instrument. A finger hole that is undercut has a larger opening to the sound chamber than to the outside of the instrument. The effect of undercutting is similar to making the hole larger, typically making the note corresponding to that hole sharper.

Barry Higgins (Yahoo/NFW, #56,324, July 30, 2014) notes that:

Undercutting is a great tool to add to your skill set — it is especially useful with large bore flutes (bass) and high flutes (high C plus) to manage the “surface” hole size (coverage) and overall spacing (reach and playability). Undercutting in a Bass flute can get quite extreme but the end result is a flute with improved playability (handling/fingering). I tend to try to balance the use of undercutting depending on the size of the flute and general reach. As mentioned it does effect cross tuning — but also tone and octave tuning as would general hole size increases (it just looks better and easier to cover with undercuts). Personally I do not like the sound of extreme undercuts but one does have to expect this in some of the extreme flute designs, just another of the flute design compromises.

How much will undercutting affect tuning?

Edward Kort indicated (Yahoo/NFW, #56,630, July 29, 2014) that, with flute walls 316″ thick, he “can get about 40 cents by undercutting”.

What other techniques can be used for tuning?

Some makers use a bore that it not straight. The shape of the bore might form the section of a cone, or could flare or constrict near the foot end of the flute. Other makers have used a choke at the foot end to adjust tuning on the lower notes.

 


Miscellaneous Flute Characteristics

How can I design flutes with less of a tendency to water out?

When a flute waters out or “wets out”, condensation has formed in the flue to the point where the sound created by the flute is severely affected, or even silenced. In this situation, the player typically has to remove and re-tie the block.

Most situations of watering out are caused by condensation forming inside the flue. Air enters the flute at about 99°F and 100% humidity. When it encounters the (typically) colder material of the flute, the air is cooled and moisture condenses onto the interior flute surfaces. Moisture condenses in the flue and also migrates into the flue from the slow air chamber.

Condensation on woodCondensation on woodCondensation on wood

Condensation on wood Larger image  Larger image  Larger image

Aside from degrading or silencing the sound of the flute, watering can cause the wood in the flue, blocks, and slow air chamber to swell. It also encourages microbial growth. Designing flutes to reduce their tendency to water out is a goal of most flute makers. Here are some suggestions:

 

Flue length. A shorter flue tends to reduce the tendency to water out (John Suttles (aka Ozark Guru), Yahoo/NFW, #56,557, June 19, 2014; Mike Jones, Yahoo/NFW, #55,772, October 1, 2013).

Flue depth. Jim V. (Yahoo/NFW, #40,415, September 26, 2008) advocates increasing flue depth to reduce watering out:

I generally make my flues deeper/taller than most people. This reduces watering out by letting any condensed moisture blow through before the droplet size gets too big.

Finish. Any finish that is applied in the flue area (including the bottom of the block) dramatically affects the tendency of the flute to water out. However, exactly whether a finish speeds or delays watering out is debatable.

One line of thinking is that a flute with no finish in the slow air chamber or flue area will absorb moisture. While this may not be ideal for the shape of the flue (due to swelling of the wood), hygiene, and the possibility of inducing a crack in the flute, it does forestall wetting out since there is less condensation in the flue area (Bradd Powless Yahoo/NFW, #39,998, August 28, 2008; Brent Adams, Yahoo/NFW, #56,661, August 3, 2014). Ken Johnson (Yahoo/NFW, #18,852, October 1, 2006) says “The only cure that I have found is to use a "bird" that is made of eastern cedar or Honduras mahogany that is unfinished on the under side. It will soak up the water like a sponge. When I am playing at night in the spring or fall I keep a couple of plain unfinished birds in my shirt pocket to change out when one bird gets soak”.

However, other flute makers have had exactly the opposite experience: Edward Kort (Yahoo/NFW, #18,853, October 1, 2006) reported that “A buffed coat of furniture paste wax on the floor of the flue and the bottom of the bird will both increase the time before watering out and make it much easier to blow out the condensation”. Bradd Powless (Yahoo/NFW, #15,554, July 5, 2004) stated that “I have always sealed the primary air chamber, flue and fipple with Acrylic (water-based Acrylic spray in hi gloss, lightly sanding with 300-600 grit between coats), and that has prevented 'watering out'”.

Surface Smoothness. If the wood in the flue area is rough, it will hold moisture droplets more readily than if the floor of the flue and the bottom of the block are smooth (Brent Adams, Yahoo/NFW, #56,661, August 3, 2014).

Wood density. Dense woods in the material that make up the flue and the bottom of the block tend to increase a flute's tendency to water out; Less dense (or “lighter”) woods reduce water-out tendency. This effect is substantial, and has been noted by many flute makers, for example: White Bear (Yahoo/NFW, #45,669, October 12, 2009), Kuzin Bruce (Yahoo/NFW, #56,663, August 3, 2014), and Gary Cope (Montana Listserver, January 10, 2002).

The faster that the surface of the material in the flue and block areas warm to match the temperature of the incoming air, the less the flute will tend to water out. That “surface warming speed” is related to several properties of the wood that are proportional to the wood's density. For details on this issue, see Chapter 4 of the authoritative and detailed [Bergman 2010] Wood Handbook — Wood as an Engineering Material, Centennial Edition. See also Mike Prairie's analysis as it relates to flute makers in Yahoo/NFW, #56,667, August 3, 2014. The paper [Goss-WP 1992] Thermal Properties of Wood and Wood Products also describes some of the methodology used in gathering the data on wood attributes.

Screens. Dusty Moore (Yahoo/NFW, #51,170, April 10, 2011) experimented with placing a small brass screen from a local pipe tobacco shop in the SAC exit hole. He reported that “it seemed to keep the flue from watering out slightly”.

Drain holes. Bob Grealish (Yahoo/NFW, #43,263, March 24, 2009) as well as Edward Kort (Yahoo/NFW, #43,197, March 19, 2009) have used drain holes at the low point of the slow air chamber to redirect moisture that condenses before it enters the flue. Ed Kort's small, angled drain hole can be seen in the photo below — it is normally covered by a separate leather strap around the flute.

    Edward Kort - Wood Wind Flutes

    Drain hole on the bottom of the flute Larger image

Ceramic inserts. Bob Grealish (Yahoo/NFW, #43,263, March 24, 2009) reported that ceramic inserts in the floor of the flue and the base of the block floor and in the bird will totally prevent moisture droplets from forming:

An insert just in the flue floor will work 90% as well, and an insert in the bird only will work 60% as well as inserts in both. Terra cotta should work well, or you can get a potter to "bisque fire" some clay strips or pieces for you to use. In order to sand them to size, you can use silicon carbide wet/dry sandpaper, with lots of water. Regular dry sand paper will chip the edges. You can start with 250 grit and go up to 2000 grit to get the surface smooth, but still porous. A diamond grinder (for stained glass work) is also nice if you have one, to remove material faster from the ceramic. I have taken bubinga flutes that watered out in less than a minute, put ceramic inserts in them and they never water out. They do, however collect a lot of water in the SAC, so they need to be shaken out frequently.
 
There's a solution for that, however. After the SAC is sealed with epoxy, I have routed a slot in the bottom of the sac all the way through the wall. Then I put a ceramic insert in the slot, and sand the outside flush. It becomes a part of the wall of the SAC that sucks up all the moisture and wicks it to the outside where it evaporates.

Hydrophilic plastic inserts. Kilani Khaleel (Yahoo/NFW, #58,223, December 20, 2016) reported on a method of John Stillwell's that uses a hydrophilic plastic material in the floor of the flue. Here is Kilani's message, including the text he quotes from John Stillwell:

… [Here is an] extract from John Stillwell's description of his solution to the problem — I have two flutes from him with this mechanism and I must say they play for hours and I have yet to suffer Wet Out. Compared to the ceramic surfaces I found the hydrophilic plastic to be quite a bit smoother. However all these mods must somehow color the sound and it's down to the subjective listener to decide what they like.
 
I have discovered that it is possible to stop wet out by lining the flue of the Love flute and the bottom of the bird with an absorbent hydrophilic plastic material. The plastic absorbs moisture like a sponge without changing dimension. Even when saturated the surface of the plastic has a surfactant quality. This prevents moisture from beading up on the surface of the plastic. Instead it sheets off into the barrel of the flute. It is droplets of water in the flue that distort the flow of air. Sometimes airflow is stopped completely. I have developed a method of retrofitting an existing Love flute with this hydrophilic plastic. This involves routing out a groove on the bottom of the bird and the flue of the flute. Next, I seal the resulting raw wood surfaces with two coats of polyurethane sanding between coats. Finally I must hand fit the plastic into the bird and flute and glue the pieces in place. Each piece of plastic must be carefully dimensioned.

Sump in the SAC. See the end of Bob Grealish's message above. Also, Jim Adams (Yahoo/NFW, #13,819, December 18, 2003) stated that “After much experimentation and over the past year I've been inlaying a strip of raw cedar in the bottom of the compression chamber of flutes not made with cedar. All but the cedar strip is sealed. Not a foolproof way to prevent watering out but it does help.

Condensers. Items added into the slow air chamber to actively condense moisture before it reaches the flue. Edward Kort (Yahoo/NFW, #43,197, March 19, 2009) describes his experience:

Lew Paxton Price suggested metal plates (pennies work great); John Stillwell uses a bit of copper tubing. I have made flutes a la Lew Price and they neither water out nor build up moisture in the SAC. However, the baffles impede rapid pressure changes.

Player Education. And finally, some basic education of the players of your flutes can go a long way to reducing the issue. Some simple thing you might suggest:

  • Limit playing time on a given flute. Most flute makers recommended 15–20 minutes per day as a maximum.
  • Warm the flute up prior to playing. You can breathe into the flute, or hold the nest area in your warm hands prior to playing.
  • Thoroughly dry the flute after playing, removing the block if you suspect a substantial amount of condensation.

 

What is the warble?

More than any other ornament or effect, the warble (or “warbling”) is the classic and distinctive sound of traditional Native American flutes. Only a small portion of present-day Native American flutes are designed to warble. But, historically, some makers went as far as to discard a flute if it did not warble.

One of the best examples of a steady-state warble from a traditional recording is this two-second sample from a recording by Turkey Legs. The original recording was provided by O. W. Jones of Wild Horse Mountain Flutes (where you can hear the full-length recording), with audio restoration by Barry Higgins of White Crow Flutes:

Steady-state Warble (two-second sample) (excerpt)

Turkey Legs.

Note that it sounds like the flute is vacillating back and forth between different notes. However, this classic warbling sound is actually the sound of different harmonic components of the same note coming into dominance at different times.

For more information, see The Warble page on this site.

Robert Gatliff (Yahoo/NFW, #14,859, April 7, 2004) posted his experience with crafted warbling flutes:

From long talks with Michael [Graham Allen] and Doc [Dr. Richard W. Payne], I did all sorts of experiments with making or retrofitting flutes to warble. I looked at warbling flutes under spectrum analyzers, and played all sorts of tricks. From this I've created a recipe for warbling:
 
Recipe for a nice continuous warble:
1) A long flute, (Sound chamber length : inner diameter) ratio ≥ 17:1
2) Brass saddle, C shaped or a O shaped one with downward beveled cutting edge. Depends on the size of the sound hole.
3) Bird with a deep recessed chimney. Basically the channel in the bird is the dimension as the true sound hole, say ¼″.
 
A low cutting edge relative to the turbulent jet of air increases the even harmonics produced. Sometimes this is just enough to make a flute warble. Having a moveable brass saddle so you can reduce the gap of a large true sound hole, allows for more experimenting with controlling the rate of the warble. Such a brass spacer needs to have a beveled cutting edge, so you get the low cutting edge. The bird with its side walls seem to make it easier to control the warble, i.e., the positions of the other elements seem to become less critical.
 
The nice thing with this sort of setup is the tinker factor. I was talking to a flute collector last night and he told me about an old flute with a real nice warble. So I asked about the fipple, “lead spacer with the cutting edge bent down”, which I interpret as a low cutting edge.
 
I understand some flute makers will constrain the size of the blowhole and/or the exit hole from the slow air chamber to create more back-pressure. This has the benefit of making it harder to over blow the flute past the point of the warble, which is possible. There can be some technique to maintaining a warble. You must blow hard enough with all holes closed, but not too hard.
 
This is not to say this is the only way to make a flute that warbles. This appears to be the most reliable, repeatable way for me to create the warble. I've seen some flutes that poorly warble, and found they had an air leak and could only warble a cycle or two.
 
One note about tuning flutes that warble. To initiate the warble, the player has to blow much harder and this causes the fundamental pitch to rise approximately a half-step. So a warbling F#, will sound like an F when you are not warbling. In turn, this affects where the finger holes go if you are a tuning your flutes.

 


Branch Flutes

What are the best woods to use when making branch flutes?

As a crafter of branch flutes, my experience has been that the very best woods are close grain, but not so dense to make working with it difficult. In my opinion very porous grain, like oak, requires a lot of sealing and is more work than what the end product is worth. Very soft woods, like basswood, are very easy to work with hand tools and can make pretty flutes, but is damaged very easily with any bump or scrape. Very hard wood, like Osage orange or Blue beech, makes a beautiful, very lovely sounding flute, but is so difficult to hand work that I would not recommend it other than as an experiment. It does, however, make a fine weapon if you ever think you will need to defend yourself with stick fighting while playing your flute in a hostile environment.

I have had good experiences with fruit woods for walking stick flutes, but as mentioned earlier, make sure you have a durable finish on the flute for long term use.

My favorite wood for flutes are: bamboo, sassafras, plum, catalpa, and cedar/juniper. My very favorite was from a piece of mimosa sent to me by Donn Shands. It carved beautifully, sounded great, and had a deep lovely pale color grain. However, I don't have regular access to that wood where I live.

— David Allen, Yahoo/NFW, #56,531, June 12, 2014


Lee Entrekin

Lee Entrekin Larger image

Problems and Fixes

This section was authored by Lee Entrekin. He send me his “Don't Panic – Flute Fixes” document and has graciously allowed me to re-publish it here.

Thanks Lee!

Every flutemaker makes mistakes in the process of creating flutes. Don't panic. Almost anything you do can be fixed. The first thing to do is stop and think about what caused the problem. Analyze the situation and decide if the flute is worth repairing, or whether it should be saved as is as a lesson for the future. Take a deep breath, go for a walk, then come back and calmly start work again. Or, especially if it was an expensive piece of wood, just panic.

The bottom of the block or the area nest is not flat

Symptoms: Breathy, weak or warbly sound, squeaks, squawks, unexpected pitch jumps.

Diagnosis: Hold bird on nest and play a long steady note with a full breath; see if condensation pattern on bottom of bird matches flue shape perfectly. Irregularities indicate a leak around the base of the bird.

Cure: Place a clean piece of sandpaper on plate glass or other very flat, sturdy surface. Draw a few squiggly lines on the bottom of the bird with a pencil and pull the bird in one direction across the sandpaper. Repeat until the lines disappear uniformly. If this doesn't fix the problem, repeat with the nest.

Note: Keep in mind that many people consider a warble a very desirable characteristic

There are leaks in the sound chamber

Symptoms: No sound, weak sound, pitch unexpectedly high for flute size, pitch jumps irregularly. May sound O.K. sometimes.

Diagnosis: Look for possible leaks in seam, cracks, and wormholes. Place finger over sound hole and blow in bottom end; feel for leaks. Put a little liquid over suspected leaking area and repeat, watching for bubbles. (This may not work with tiny holes that may be getting clogged off and on with sawdust.)

Cure:

  1. Cover sound hole and pour polyurethane or other finish into bore. Old, thick finish is good for this. Swish around and pour out.
  2. Seal hole with glue and sawdust or crushed stone.
  3. Sometimes, just applying finish to the outside of the flute will seal tiny holes, but this may not be a permanent fix.

The finger holes are in the wrong place

Symptoms / Diagnosis: After placing first finger hole, it is either way too small and already too sharp, or it's getting too big and still way flat.

Cure: Either drill out and plug hole (see below) or rout a channel out where the finger holes will be and cut a contrasting piece of wood to fit. Redrill the holes in the right place. In some cases, putting tuning holes in and raising the pitch of the fundamental will fix this without major surgery.

The finger holes are too big

Symptoms: You realize that any finger hole on the flute has gotten too large (sharp), although it's in about the right place. You can't drill it smaller.

Diagnosis: Finger hole is too big (duh!).

Cure:

  1. Put a small drop of thick glue on the side of the hole nearest the mouth, and drop a little sawdust into it. Repeat until it's in tune. Thick CA glue works well for this.
  2. Drill the hole out using a bit the size of a standard dowel. Cut a short piece of dowel and plug the hole. When inserting the plug, put a piece of dowel in the bore of the flute to keep the plug from extending too far in. Redrill the hole and pretend you meant to do it that way.

The pitch of top (sixth) hole is too high or jumps

Symptoms / Diagnosis: After all the finger holes are drilled and tuned, the top hole will jump to a higher note uncontrollably. Sometimes, the right note can be played with a soft breath. All others notes are O.K.

Cure: This may be caused by the top finger hole being too close to the sound hole. This is difficult to fix. You can relocate the finger hole down slightly, or replace the entire set of finger holes (see above).

The flute overblows easily

Symptoms / Diagnosis: The fundamental note jumps up an octave with little breath

Cure: This is often caused by the airstream not hitting the splitting edge of the sound hole just right. Flatten the bottom of the flue, then sight down the flue to the cutting edge. It should be just slightly higher than the flue bottom. Either gradually make the flue deeper, or bevel the cutting edge on top. Also try a very slight bevel on the upstream side of the sound hole or the bottom of the bird.

The fundamental note is too high or too low

Symptoms / Diagnosis: The fundamental plays just fine, but it's between keys.

Cure: It's best to fix this before you put the fingerholes in. If the fundamental is too sharp:

  1. add a chimney to the bird or make the chimney deeper,
  2. make a bird that projects over the sound hole, or
  3. add an end cap with a bore smaller than the bore of the flute.

If the fundamental is too flat, trim a little off the end of the flute or add tuning holes. If the flute has an end cap that has a hole smaller than the bore, enlarge the hole.

You have accidentally routed off the nest

Symptoms: In your enthusiasm to finish the flute, and/or forgetting which side was up, you went too far with the router, and rounded off the entire top of the flute, including the nest. You can also do this with a lathe.

Diagnosis: Flute is nicely round in all the wrong places.

Cure: Using a rasp or a flat router bit (you wanted to use the router again, didn't you?), flatten the area where the nest should have been to a point where it's slightly wider than the base of the bird. The flat area should be slightly longer than the original nest. Cut a matching or contrasting piece of wood and glue it in place. Cut a new flue and sound hole, and round the edges of the new piece to match the existing contour of the flute. Call it a "design element."

The sound hole is too long

Symptoms: In your pursuit of the perfect sound, you have filed the sound hole so much that it's too long.

Diagnosis: Flute sounds breathy, lacks volume, or doesn't play at all.

Cure: Cut a piece of wood veneer the width of the sound hole and slightly deeper than the back wall and glue it to the back wall of the sound hole. After it dries, sand it to match the floor of the flue.


Other Resources

Where can I find more information on crafting Native American flutes?

Flutopedia has a list of References on Crafting Native American Flutes.

Also, here are some links to resources within Flutopedia:

 

 
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To cite this page on Wikipedia: <ref name="Goss_2017_faq_craft"> {{cite web |last=Goss |first=Clint |title=FAQ about Crafting Native American Flutes |url=http://www.Flutopedia.com/faq_craft.htm |date=15 April 2017 |website=Flutopedia |access-date=<YOUR RETRIEVAL DATE> }}</ref>