CONICAL LOW D TIN WHISTLE

CONICAL D WHISTLE

A four-part printed whistle with a tapered bore.

Above I play a scale on this tin whistle. The second octave is slightly out of tune.

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WHY THIS EXISTS

Because I wanted a whistle I could actually play, and playability

turned out to be a geometry problem rather than a tuning one.

The usual way to lay out tone holes is to put each one where its

own note wants it. On a tapered bore that gives an uneven hand:

two holes close together set the wrist at one angle and the third

drags it out of that angle again. I built that version. The span

was fine, the stretch was not, and the awkward angles made the

near holes harder to SEAL rather than harder to reach -- which is

a fault a span measurement cannot see.

So the hand decides the positions here, and the tuning is solved

around them with hole diameter and, on the lowest hole, wall

thickness. Both hands are 70mm across with even gaps inside them.

Two other things came out of the same aim:

THE THIRD AND SIXTH HOLES ARE OFFSET, about 20 degrees, in

opposite directions. Those are the ring fingers, and the offset

follows how the wrist actually rotates rather than how long the

fingers are -- which is why the two hands go opposite ways

instead of both the same way.

THE BORE IS CONICAL, 22.35mm at the top of the body down to

16.9mm at the foot. It gives a rounder, less piercing tone than

a straight tube, and it lets the finger holes stay large enough

to seal comfortably without the top notes going shrill.

WHAT YOU GET

Four STL files, printed in this order down the instrument:

FinalMouthpiece_socket_fixed the fipple head

ConicalD_Neck 151mm, plain tube

VerticalFlute_Body1 holes 1-3, upper hand

VerticalFlute_Body2_Foot holes 4-6, lower hand, and foot

All friction-fit, 0.30mm clearance on every joint. It comes apart

for cleaning and transport, and it wants no glue anywhere.

ASSEMBLY. Push the joints together dry and firmly, until the

shoulders meet -- a joint that is not fully home makes the

instrument longer and everything above it flat. If a joint is

tight, sand the TENON (the male spigot), never ream the socket:

the tenon's outside touches no air column, so removing material

there costs nothing acoustically, while opening a socket cannot

be undone. If a joint is loose after a few dozen assemblies, a

turn of PTFE plumber's tape on the tenon is the standard fix.

PRINTING

PLA, 0.2mm layers, 3 perimeters. Print the bodies diagonally with

the tone holes facing UP, and give Body2 a brim -- it is the

longest part on the plate.

Do not scale anything. A whistle is not scale-invariant: the wall

thickness and the hole diameters do different acoustic jobs and

they do not move together.

TUNING, AND WHAT "IN TUNE" MEANS HERE

As printed on my machine it reads:

holes covered 6 5 4 3 2 1 0

note D4 E4 F#4 G4 A4 B4 C#5

Hz 290 325 361 386 440 490 552

That is a D major scale sitting about 20 cents flat overall, and

it comes up to pitch with normal breath support. A4 lands on 440

exactly. If your print reads flat as a whole, that is the same

thing mine does and it is not a fault.

EVERYTHING ERRS IN THE RECOVERABLE DIRECTION, ON PURPOSE:

the foot is left LONG -- a saw cut raises the bottom note

hole 6 is left SMALL -- a round file raises its note

the boss on hole 6 is

left TALL -- sanding it down raises E4

Every one of those is a hand tool and none of them needs a

reprint. That matters, because your printer is not my printer and

a few tenths of a millimetre in the wrong place is worth more

cents than you would expect. Go slowly, a little at a time, and

check with a tuner between passes. None of it goes back.

THE BOSS ON HOLE 6

There is a raised collar around the lowest hole. It is not

decoration. A tone hole's pitch depends on its diameter, its

position AND the thickness of wall it passes through, and that

third lever is what let hole 6 sit where the hand wants it

instead of where the note wanted it. Without the boss the hole

would have to be about 6.8mm -- small enough to go veiled and

stuffy on the note that is hardest to voice anyway.

LIMITS, HONESTLY

This is one instrument, printed on one machine, played by one

person. Take all of the following seriously:

IT IS ABOUT 20 CENTS FLAT as printed, corrected by breath.

Fixable with a 3mm trim off the foot if it bothers you, but the

foot is coupled -- taking length off down there moves D4 and E4

together, roughly 3 cents on E4 for every 4 on D4. Changing one

note changes two.

F#4 IS THE WEAKEST NOTE, a little flat relative to its

neighbours. It has been the worst-behaved note through every

round of tuning. Hole 5 can be opened slightly if it bothers

you.

THE PRINTED BOSS IS NOT WELL CHARACTERISED. It works on this

instrument. How much effect it delivers on a different printer,

in a different filament, at a different layer height, nobody

knows -- including me. It is the newest idea here and the least

tested.

ONLY THE FIRST OCTAVE IS TUNED. The second octave overblows and

is usable, but no work has been done on it.

THE TUNING MODEL IS PARTLY EMPIRICAL. Hole diameter, in

particular, has delivered anywhere between 29% and 142% of

what was predicted for it. The numbers in these files came from

measuring a real instrument far more than from calculating one.

THE FILENAMES SAY "VerticalFlute". The two body sections came

across from an abandoned transverse flute and kept their names.

The parts are right; the names are historical.

THESE ARE STLs, so the dimensions above are what you get. If

you want to move a hole or change a diameter you are editing a

mesh, which is why every adjustment described here is one you

can make with a file or a saw on the printed part instead.

IF YOU BUILD ONE

I would genuinely like to know what it reads on your printer,

especially the bottom note and E4. One instrument is an anecdote.

Licensed CC BY-NC-SA. Do what you like with it non-commercially,

share alike, and say where it came from.