A whistle that looks like a gummy fish.

This is meant to be an alert and safety whistle and while it’s a fun shape, it’s not a toy! It’s a bitonal whistle that can range from 105 to 130 dB up close, depending on how hard you blow. I measured the frequencies of the sides individually to be about 3000 Hz and 3300 Hz.

If you are going to test or use this whistle a lot, or blow as hard you can to get the top volume, I recommend using some sort of ear protection. 130 dB is classified in the “threshold of pain” for hearing and can damage your hearing really quickly! The loudness falls off the farther away you get, so while people farther away will experience a lower decibel level, the person who blows the whistle (or anyone right next to them) is always going to experience it at its loudest.

How to print:

• 3 walls/perimeters
• Classic slicing preferred
• 0.4mm line width
• Aligned seams

• The seam placement I use (you want to keep from messing up geometry important to how the whistle works):

  

   

• Bridging angle: 180º
  • If you rotate the whistle from its starting orientation you will want to adjust this to compensate.
• For the bridging layer that closes the whistle chambers, use a height range modifier and change 'infill/perimeter overlap' to 100%. (In PrusaSlicer you right click the object in the list, select ‘Height Range Modifier’, set the modifier (4.4mm to 4.6+mm), then right click that Range on the object list and Advanced > Infill/perimeters overlap to 100%.)
• I also recommend making sure ‘avoid crossing perimeters’ is turned off.