Wood WhistleThis article and video contributed by Ron Walters
Exact dimensions are not critical. I drew concentric circles of the 1/2" thick body using 1-1/4" diameter and 1" diameter fender washers. The inside circle is used to align the Forstner bit. The 1-1/4" diameter fender washer was also used to draw the 1/8" thick side caps.
I have CAD captured the whistle, but did the drawing in metric. You can make a 1:1 printout of the drawings at left by downloading the eval version of my BigPrint program and just dragging the image at left onto the program. Or you can print the print the pdf. You can alslo download the whistle SketchUp model
The middle layer should be cut 13 mm thick, the two sides 3 mm thick.
Shorten the end of the top part of the mouthpiece, either by cutting or by sanding. Sand both inside faces of the mouthpiece (what will be the air slot) smooth. The inside of the body should be smooth. Maintain the sharp edge of the wind cutter.
Now is your opportunity to "tune" your whistle. Temporarily place the body of the whistle on the side cap, aligning the parts as shown with an approximate 1/16" slot between the top and bottom portions of the mouthpiece.
Blow on the whistle to test it.
Make sure your whistle is going to sound its best by adjusting the body position and the size of the air slot. When you are happy with the sound, glue the parts together. I filed and sanded everything smooth and radiused the edges.
Experiment with the various dimensions of the whistle and you can probably reduce the size of the mouth enabling the use of a small ball or pellet inside the body, which will tumble around in the turbulent air when you blow on the whistle. The tumbling ball will disrupt the airflow creating pressure fluctuations within the body and the warbling sound we associate with a police whistle.
Enjoy your whistle!