SunDIY Project:
A Penny Whistle in D

Here are my notes on constructing a penny whistle in the key of D. I made this two years ago and so some of the theory is lost on me now but following my steps will still yield a playable instrument. All measurements are in inches (sorry I live in a backward country).

The Completed Penny Whistle

Using a hack saw or similar cutter:
Begin by cutting a piece of 1/2" PVC Water Pipe to 11 3/8" in length.
Cut a second piece to 1 1/8"
Cut a piece of wooden dowel that fits snugly inside the PVC to 1".

The short pieces

Take a piece out of one end of the long pipe that's 1/4" wide and 1" long.
Bevel the short side of this rectangle as shown.
DO NOT insert the wooden plug yet.

The Notch

This Penny Whistle is in the key of D.
The holes play C#, B, A, G, F#, and E.
Measureing from the notch you cut, make marks on the tube at:
4 1/2", 5 5/16", 6", 7 1/16", 7 13/16", and 8 13/16".
At these points, drill holes of
9/32, 9/32, 9/32, 1/4, 25/64 & 23/64 inches respectively.

Press the dowel into the end of the main tube leaving a 1/8" space to the bottom of the bevel you cut. (See the above picture).

Slice the short piece of pipe open lengthwise.
Slide it over the end of the main body.
Cut off the very tip of the main body, plug and short piece at 45 degrees.

Completed End

Et Voila!

Notes:
Your flute is essentially complete. Some fine tuning via adjustment of the short piece and plug may be needed for optimal sound production.

The holes are different sizes because that is how the individual notes can be set in tune. It would be out of tune if they were all the same size. If you are using metric drills, start with a tiny hole and drill progressively larger holes. Use a chromatic tuner to know when you hit the note.

Typical cutting tools I used were a hack saw, a pair of diagonal or "wire" cutters, and a utility knife. PLEASE be careful cutting the lengthwise cut in the short tube! Wear gloves or something.