Equal-Spaced Finger Hole Placement

The method of placing the finger holes described on this page is largely taken from the 16th edition of Keith Stanford's flute-crafting manual ([Stanford 2014]). Keith has been very generous in letting me re-publish it here. Keith offers the full flute-crafting manual (and other publications) on his CherryCows web site.

Keith Stanford, aka "Ki-e-ta"

Preamble

Using a hole-placement method that spaces the finger holes on the flute an equal distance apart is preferred by many flute makers and players. The finger holes are relatively easy to position, and some players find that the equal spacing makes it easier to re-locate the finger holes with your fingers after you lift them off to play a note.

However, note that equal spacing does not typically mean that the finger holes will be equally sized. Of course, this depends on the tuning method you use.

This page primarily describes Keith Stanford's CherryCows Knuckle Method (which actually uses a ruler rather than your knuckles). This method has been used by many makers over a long period of time. I have altered some of the terminology to match that used on other parts of Flutopedia.

Finger Hole Location

Measure the total physical length of the bore of the flute: the distance from the bottom end of the plug to the open foot end of the flute. Then divide this in half and mark a “midway” point on the body of the flute.

From that “midway” mark, measure South ¼″ and that will be your finger hole #3 (this page is using “flute-maker numbering”). The rest of this page will use “FH” for “finger hole”.

From FH #3, measure 1” down toward the South end of the flute. That will be your FH #2. Measure one more time 1” toward the South end and that is your FH #1.

Now go back up to your original FH, the #3 FH mark, and measure 1” up toward the North end of the flute. That will be your FH #4. (That #4 FH is ¾” from the “midway” mark, and 1” from the #3 FH.) Measure again 1” toward the North end of the flute and that is your FH #5. Measure one more time 1” toward the North end and that is your FH #6.

You should have a total of six equally spaced finger holes, all 1” apart.

Note: All measurements are made to the center of the finger holes.

Figure 1. Flute marked for equally-spaced finger holes.

Wall Thickness

The thickness of the bore wall will influence the finger hole locations. If your bore wall thickness is 3/16”, then the finger hole locations that you just marked will be fine.

If the bore wall thickness is thinner than 3/16”, you will want to move all of the finger holes up (North) anywhere from 1/8” to 1/4”.

If the bore wall thickness is thicker than 3/16”, you will want to move all of the finger holes down (South) anywhere from 1/8” to 1/4”.

Bore Diameter

As the bore diameter increases, the top three finger holes (#4, #5, and #6) may need to all be moved upwards (i.e. North). Otherwise, after you tune the flute, the top three finger holes might end up too large in diameter for you to play comfortably. The bottom three finger holes (#1, #2, and #3) will not need to be moved up.

For flutes with a bore diameter of 7/8” or less, all of the finger holes can remain one inch apart. However, flutes with bore diameters larger than 7/8” will require the finger hole spacing to be greater than one inch apart. For larger bore flutes, a good rule-of-thumb is to make the finger hole spacing equivalent to the bore diameter. For instance, if the bore diameter is 1¼”, then the finger hole spacing should be 1¼”.

If you are making a flute with a larger bore diameter and have kept your bore wall thickness at 3/16”, you will need to move the top three finger holes North (only the top three finger holes). Do this by moving the #4 finger hole further North of the #3 hole than the normal one inch:

Note: You will still have the top three finger holes all spaced the same distance apart from each other, and the bottom three finger holes all spaced the same distance apart from each other.

Drilling the Finger Holes

Once you have all of your finger holes properly located and marked, drill a ⅛” hole at each of these six marks. Then enlarge these holes by gradually drilling larger holes, finishing with a 3/16” drill bit.

I find that it is more convenient to drill all of the finger holes at one time. Every time you drill a hole, you are changing the flow of the air-stream in the sound chamber. If you were to proceed by drilling one hole and tun it, and then drill another hole and tune it, etc., those ‘tuned’ holes will change slightly by the time you get to FH #6. By drilling all the finger holes at the same time, whatever turbulence you were going to get is already there, and you will overcome that turbulence immediately as you tune each hole.

Note: Be sure to completely clean out any splinters caused by drilling the finger holes.