Make a D flute
5 Hole Minor Pentanic
Material:
1 24” x 1” PVC Pipe
1 1” Coupler
1 1” Reducer
1 piece of 1” dowel or equivalent
Tools: Set of small hobby files.
1: square
1: flat
1: flat with rounded back
1: 1/4” wood chisel
1: carving knife
1: chromatic guitar tuner
Drill with graduated sizes starting at 1/8 inch
Hack saw or miter saw
On
what you determine to be
the mouth end of the flute, put the coupler on and push it all the
way on. Make a mark with a pencil. This will be the placement of
the TSH (true sound hole). Measure and mark a rectangle from the
point you will make the TSH. This will be where you carve out the
flue. It should be 3/8” to 1/2” wide and extend from the mark you
made to the end of the flute (mouth end). Be sure the flue
extends clear off the flute, so air can enter the flue
Now, chisel and file out the
rectangle from the side closest to the mouth end of the flute
extending all the way to the end. It should be no deeper than a
credit card thickness.
Centered on the “flue”
you just carved, drill a 1/8” hole where you made pencil line. Put
the tip of the drill bit on the line. This will bring the mouth side
edge to just under the lip of the coupler when in place. Use the
square file to file a slot the same width as the flue and only as
deep as the file. Now take the flat file and
make it a perfect rectangle.
Carve/sand/file the dowel so it will
fit snugly into the PVC pipe. Cut off a piece that will block the end
of the pipe and extend about half way to 2/3 of the way to the TSH.
The will leave some back-flow in the pipe. Glue the wooden piece in
the mouth end of the pipe ensuring that it does not extend all the
way to the sound hole.
Now slowly begin to file
the
TSH with the flat file, on the edge towards the foot end of the TSH. Maintain the
perfect rectangle shape and a nice, squared, flat edge. Make an
undercut angle on the foot edge of the TSH that is approx 35 degrees.
It does not need to be exactly 35 degrees, but close. Work the edge
and the bevel in small steps. You should maintain a thin flat edge
of about 1/15th to 1/16th of an inch so the TSH
edge is not sharp, but blunt.
As you file and work the
edge, place the coupler on the flute and line it up with the edge
nearest the mouth end of the flute. Blow very, very gently. You are
looking for a tone, even if it is high pitched. Once you have a tone,
begin to file the bevel and the blunt edge increasing the TSH size
toward the foot end of the flute. A little change makes a big
difference. Keep testing until you get a fairly clear tone. If your
TSH reaches 1/4” deep, you have likely gone to far and the flute will
begin sounding breathy.
Once you have a fairly
clear tone, check it with a chromatic guitar tuner. It will likely
be lower than a D. Using a miter saw or hack saw, cut off small
pieces from the foot end in not more than 1/8” increments checking
the tuning each time. Note how much change there is in the note
pitch each time so you can judge whether to take more off. When you get to a
point you feel another cut might take off too much, use a file and
fine tune the body of the flute to a perfect “D”.
Now go to the TSH and tweak
the blunt edge and bevel noting what improvement if any, the
adjustment makes. When you have a clear tone. That is good enough! You
DO NOT want to fine tune past good. It cannot be put back on if
you go too far.
Now that you have a good
clear base pitch for the flute it is time to make the finger holes. It
is very important to start with small holes. Use a 1/8” or
smaller bit for the first drilling. Check the tuning and increase 1
bit size until you are close enough to the correct pitch that the
next size seems will take it to high. If the hole seems to be
getting too big for your finger, you started too low on the flute. At
that point you can try undercutting to increase the hole size and
keep the overall hole useable.
Here are the measurements
for the hole placement for the working flute I made during this
tutorial.
The overall length of the main sound chamber (measured inside to the internal block I made) is 19.5”.
Keep in mind the size of
the
TSH can affect things so these are approximates when applied to your flute. If you start with
small bits as you drill, it should work out fine.
The distance for the
fingering holes is measured from the mouth end edge of the TSH.
Hole 1 (closest to the foot) is 13.5 to the center of the hole
Hole 2 (second from the foot) is 11 & 5/8” to the center of the hole
Hole 3 (third from the foot) is 9 & 3/4” to the center of the hole
Hole 4 (fourth from the foot) is 7” to the center of the hole
Hold 5 (fifth from the foot) is 5.25” to the center of the hole
The notes you are aiming for are:
Lowest (all holes covered): D
Lowest hole uncovered: F
2 lowest holes uncovered: G
3 lowest holes uncovered: A
4 lowest holes uncoverd: C
All holes uncoverd: D
Adding holes tends to
flatten the lower holes. After all are tuned, you may need to go back
and tweak the holes again bringing them into perfect tune.
When
you play the flute, it
is designed so the coupler can be moved to adjust the alignment of
the edge of the TSH to get the clearest notes. Also it can be removed
to dry out the flue. It can get clogged with moisture. Experiment as
you go. Materials are inexpensive for these flutes so you can make
more than one. The width of the TSH and flue can affect the volume
and the tone of the flute. The depth of the flute has an impact on
volume. You should wind up with fairly large fingering holes that
are fairly consistent in size. If you make a smaller flute, do the
math to find percentages for the placement of the holes. You will
need to drop to a smaller pipe for the flutes around F# and above. 3/4”
works well and if you make really high flutes, 1/2” may be
in order. There are many good tools on the web for placing the
holes, but keep in mind, unless your work is perfect, there will be
variance. If you err, err on the low side as you can make a note
sharper, you can't flatten it without pluggin the hole and
redrilling. Flutes with plugged holes don't look all that great.
These principles can be applied to making wooden flutes. Since they don't make couplers or wooden tubes, you will need to make a slow air chamber (this was created by the coupler) and there will need to be an exit to the flue so the air can flow out of the slow chamber, down the flue and strike the TSH edge. A flat block is used to cover the flue. It can be carved to what ever design you want. Be sure the contact area with the body of the flute is flat so there is no air leakage.
Here
is a photo of some of the flute's I have built. The flute I made for
this tutorial is the white PVC at the bottom of the rack. Notice
the holes are not lined up. This is to accommodate the reach of
my fingers. Moving the holes around the flute makes them easier to
reach. It is a fairly good stretch to reach the holes on this
flute, so I tailored them to my hand for ease of playing.
I have linked to a song recorded with the PVC flute made for this tutorial. It is linked below.
Hope you have fun making your flute!
Song sample: Sojourn (Copyright 2011, All Rights Reserved)