Pitch Changer for Portable Airhorn

The previously shared Portable Air Horn produces a monotonous sound. By using a larger or smaller horn, the pitch can be slightly changed.

By moving the hand/finger in the opening you can also change the pitch. But since your hand is in the opening the soundlevel is reduced. First thought was to create some kind of loose plunger, but it was difficult to work with this. The plunger actually needed a guide.

What has now been created is a plunger that can be easily moved up and down through the guide ring using one or two fingers. A number of magnets (Ø8x5) have been used to allow the plunger to spring back automatically. (model can be used without, but then the retracting is done by pulling back yourself, alternations are then slower) These magnets are placed in a repelling configuration so that the plunger automatically returns to the open position. To prevent the exit of the horn from being completely blocked, 3 narrow channels have been made in the plunger.

When using, you need to tap the plunger while blowing. In this way the plunger moves up and down quickly (by springing back due to the magnetic forces). By using 2-finger swap you can make the alternations even faster.

The sound that can be produced now reminds me of my childhood when we played cowboy and Indian. To produce an Indian sound you made a monotonous sound and quickly moved your hand up and down towards your mouth. If you printed the original for the kids and are already partially regretting it, don't print this upgrade! They will definitely drive you crazy with this one!

Like the Airhorn it's easy printing. All parts can be printed without support.
I printed them with 0.4 nozzle and 0.2 layer thickness and 15% infill.
Print all as positioned in the STL's.

For assembly see drawing below:

In case you're wondering how it sounds (warning, very annoying..)