Here's a quick download for you to try. This is a experimental mechanism (if that is the right word) which will be used in a more complete kit at a later date. It does work though and is rather fun!
The swanee whistle is a whistle with variable pitch. Pull the slider in and out and the pitch goes up and down. Download and print out the file from the end of this blog post, it is free for anyone to try.
It is a simple model but must be put together carefully and accurately. I printed out the parts sheet onto slightly heavier card than I usually use. 280 micron.
Score the dotted lines, cut out the air hole then cut out the parts carefully.
Fold the outer tube round and glue it together accurately. Fit the cover over the end of the tube so that the bottom edges of the cover line up with the bottom of the outer tube.
Assemble the inner tube. Set both parts to one side until the glue is completely dry.
Fit the inner tube into the outer tube. It should be a close fit but be free to move in and out.
Blow through the hole between the cover and the outer tube and the whistle should sound. Pull the inner tube in and out and the pitch will change!
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