Ultrasonic Dog Whistle 22 kHz

WARNING:
This is a dog whistle and not a toy! It's very loud which can harm the ears, so please protect your ears and don't use it near other people or animals!

About:
This dog whistle produces a very loud tone of about 22 kHz. This frequency is in the ultrasonic range, so it's very likely that you won't hear the sound at all - unlike many animals and some younger people! I therefore strongly recommend a frequency measurement app for testing. I use this android app.

How to print:
First of all: Due to the short wavelengths of ultrasound, this whistle has very small structures inside. Therefore, this print will only be successful on a very precise printer. Even small deviations (for example in the flow or the dimensional accuracy of the printer) can lead to frequency deviations or cause the whistle not to work at all.

Use a 0.4mm nozzle with a line width of 0.4 mm and a layer height of 0.2 mm, 6 top layers and 6 bottom layers.

The whistle requires correct positioning of the Z-seam - it shouldn't be placed in the narrow air passages inside the whistle. The Z-seam should be positioned as shown in the last 2 images above. Use the “Z Seam Alignment: User specified” option in Cura or the "Seam Painting" option in PrusaSlicer and Bambu Studio to achieve this.

Print slowly!

Filament selection:
It is strongly recommended not to use fancy filament types, but instead use standard PLA. Variants such as “matte”, “silk”, “glitter”, etc. should be avoided as they can affect the accuracy of the walls in the airflow.