Well, thought for this week I would try to lay out my thoughts on whistle mouth pieces and what I go through in their construction.
First off, you don't get very far into the building of whistles when you find that the mouthpiece is where it all happens. The characteristics of the mouthpiece airway and blade (or fipple) are very important in the overall sound of the whistle.
I have spent much time and effort in the design and construction techniques used in building my mouthpieces. You have only to look at the box of rejects (numbering well over 30 that just didn't give the sound I like) to realize that it is not a "cut and dried" process. Their are many variables involved. Some of the variables in the mouthpiece are: the air way (it's width, height and length), the blade's sharpness, angle and degree of blade under cutting and the shape and position of the airway block (the piece that forms the bottom of the airway). The interaction of the many, many possibilities of these variables is very great. Finding the "just right" combination of these variables is just about impossible. I finally settled on a combination that gives the sound I like.
I should also note that the final mouthpiece design is very much a compromise. You would like a mouthpiece that requires little air to blow, plays with equal loudness through 2 1/2 octaves and generates just the quality of sound you like throughout it's entire range. This does not happen!
To get the qualities I want, my mouthpieces require a little more air for the volume I want. The design strives for ease of blowing the low notes in the first octave at the expense of a little more air in upper second octave. Overall, my whistles would be considered quite loud, the sort of thing you want for session playing.
Another consideration in the design is the choice of materials used in their construction. I wanted a material that offered durability, ease of construction, suitable appearance and low cost. I found that Delren polymer filled the bill nicely.
The picture above is an attempt at showing the steps I go through in the construction of the mouth pieces.
1 - The leftmost item is the raw 3/4 inch diameter Delren rod I start with. It is cut to 3 1/2 inch length.
2 - The second item shows the rod bored through at a 1/2 inch diameter. The end has been turned down (using a lathe) to a diameter and length yielding the airway height and length.
3 - The third item shows the rod, the airway block, the airway cover, the brass tuning slide and the brass end ring. The rod airway slot has been cut on the mill and the ramp for the blade has also been milled.
4 - The forth item is a completed mouthpiece. The blade has been shaped very carefully by hand to it's final dimensions.
Well, that's it for now. I welcome any questions you might have about what I have posted here.
Next week I will be out of town but the following week I will go into the construction and tuning of the whistle tube.