Step 1: Making the Whistle Body
Make
2 pinch pots and stick them together to make a hollow form.
This will form the body of the whistle. It is not absolutely
necessary for the body to be spherical. It can be almost any shape.
Step
2: Attaching the whistle nozzle

Take
a small block of clay and attach it to the clay body. The top of
the block should be aligned with the top of the sphere.
Note: A nozzle is not technically needed for the whistle
although it provides a handy place to stick your mouth while you're blowing
into the whistle.
Step 3: Making the whistle opening
Insert
a thin stick into the nozzle, through the nozzle and into the hollow body.
The top of the stick must be aligned
with the inside top of the clay body. Using any sharp tool, cut an
angled opening in the top of the whistle as shown in the diagram.
The edge of the opening must be vertical and at the point where the stick
enters the clay body. The other edge must be at an angle (say, 45
degrees).
Note: the angle, width, and length of the opening are variables to play
with. Generally, the angle is 45 degrees, the width should be no
wider than the stick, and the length should be about the width.
At this point, blowing into your whistle should
produce a single tone. If it does not, here are some likely problems
and their solution.
Improper
Opening Placement
In this figure, examples 1 and 2 show improper opening placements.
The whistle will sound best when the opening begins directly above the
spot where the nozzle enters the clay body.
[Example 1 may work... I haven't researched it well enough.
Example 2, though, is a whistle killer.]
The
Drooping Opening
When forming the angled cut of the whistle opening, it is easy to push
the surface down into the hollow cavity. This leads to poor sound
quality. It is much better to have the inside surface of the clay
(at this angled cut) in-line with the nozzle, see the figure to the right.
To correct this situation, cut open the whistle and push the angled
cut back into place. Reseal the whistle with some clay slip and continue.
Opening
Sizes
I have found the size of the opening to be an important factor to sound
quality. As seen in the figure to the right (looking down at the
top of the whistle), a small opening gives no sound or poor sound.
As the opening gets larger, the sound suddenly improves. I have read
in some places that the opening should be a square and my experience tends
to affirm this. Still, you might try enlarging the opening if you
are having difficulty getting your whistle to sound good.
Step 4: Changing the Pitch of
the Whistle
Once
you have the whistle body made, you can put holes in it to change the tone
(or pitch). In general, the larger the hole the higher the pitch.
Likewise, the more holes the higher the pitch.
Note: It's a good idea to put all the holes in the clay
before
it is too hard to re-work the nozzle and opening. If the whistle
sounds good at it's highest pitch it will also sound good at it's lowest
pitch. The reverse is not always true.
Vary the Hole Sizes
If you put more than 1 hole in the whistle, you may want to consider
making the holes different sizes. This will maximize the number of
tones it will produce. For example, if you make 2 similar holes you
will have 3 tones. From low to high these tones are "both holes closed",
"one hole open", and "boths holes open". However, if you make the
holes different sizes then you will have 4 tones: "both holes closed",
"small hole open", "large hole open", and "both holes open".
Whistle versus Ocarina
An ocarina is a multiple-tone whistle.
Step 5: Tuning Your Whistle
Eventually, you will want to tune your ocarina so that you can really
play music with it.
The 3-Hole System
An octave is 8 notes. To achieve 8 notes you need at least 3 holes
all with different sizes. If 0 represents a closed
hole and 1 is an open hole and hole size goes left to right for larger
to smaller, an octave scale is
| doe |
ray |
me |
fa |
so |
la |
ti |
doe |
| 000 |
001 |
010 |
011 |
100 |
101 |
110 |
111 |
For those mathemeticians out there, this is like binary counting.
See the animated figure on playing the scales.
-
Start with no holes to establish "doe".
-
Cut the hole #1 to make "ray".
-
Cover hole #1 and cut hole #2 to make "me".
-
Try out the scale so far: "doe", "ray", "me", "fa".
-
Cover holes #1 and #2. Cut hole #3 to make "soe".
-
While this technique will give you 8 distinct notes, it may not
create a true octave scale. I have heard of a 4-hole technique for making a true octave scale (see below).
The 4-Hole True Octave System
A visitor to this website pointed me to another site deplicting the 4-hole octave scale. I've reproduced the fingering here.
When cutting holes in your ocarina for the 4-hole system, follow the method described above: cut one hole at a time going from low pitch to high pitch and following the fingering system.
Clay Shrinkage Issues
Rule #1 (well, a small number) in Clay: Clay Shrinks
When firing your ocarina to, say, Cone 6 the clay will shrink about 10 to 12% in each direction. This will markedly decrease the volume of the whistle (about 30%) resulting in a higher pitch. A carefully tuned pre-fired ocarina will be out of tune after it is fired. I suspect that's one reason why commercial ocarina makers use molds rather than hand-building.
I know of 2 ways around this problem:
1) After many years of building whistles you know exactly what size the wet clay body should be and what size to make the holes. Needless to say, this requires serious planning before making an oddly shaped whistle body.
2) Make a Re-tuning Slit in the ocarina body. This is a thin slit opening and, effectively, acts as a variable-sized hole. While playing the ocarina, the Re-tuning Slit is partially covered with your thumb to the correct amount that DOE truly sounds like DOE.
While the clay body is wet, cut the Re-tuning Slit and leave it open while cutting the normal fingering openings. After the ocarina is fired, determine how much the slit needs to be covered to perfectly tuned the ocarina. Either mark this position or permanently cover the slit (glue on a cover).
Note: I haven't actually tried out this technique out.
Step 6: Decorating Your Whistle
Once your whistle is tooting, you may wish to decorate it. You
can carve into it, paint it, or add to it. I like to add shapes to
whistles. For example, below are pieces to turn a whistle into a
Bird Flute. Note, the bird head is hollow and the whistle works by
blowing into the beak.
Here
is an example of a dinosaur-shaped whistle.