Plastic Instrument Building Tips
Building Plastic Whistle Fipples and/or Wooden Windways works very well
if you have a Cross-Vise.
By using the Cross-vise with a surface router bit, it becomes easier to cut nicely performing
Windways. Below is the design which I used to use to build PVC Whisles 5 years ago.

Note that the air goes in on the right, into the water trap chamber. A plug made of polyclay is
Installed inside the pipe causes the air to move up to the semi-circle opening.
The air must then shoot across the embouchure hole because the coupler covers the opening and
Prevents the air from going straight up.
The surface of the windway must be smooth, smooth, smooth. Router markes can be polished out by
Rubbing the windway surface with a piece of cloth that is soaked in acetone. Acetone makes PVC soft.
For even better performance, the windway surface can be painted with a waterproof clear high gloss paint.
The better the surface, the better the volume of the instrument.
Longer windways can be experiemented with such as in recorders, be warned though that long windways
clog easier.