DESIGNER Whistle

Why Whistles?

Different whistles. Different tasks. This is a designer's version of the PROTEST Whistle. This whistle works great for emergencies, personal safety or protests. It has an intense, distinctive two-tone sound.

PS These whistles are excellent protest whistles. Print a bunch and bring them to local events and share with fellow protesters. If you'd prefer whistles that also send a message, see the PROTEST Whistles and NICE Whistles linked below. 

Whistle Design

I'm  a designer and I frequently use 3D printers for design development and prototyping. The goal for this project was to create really good small whistles with a rich, full, distinctive sound that 3D prints well that can be customized. Being a simple device, I assumed whistles would be easy. Turns out designing a good whistle is hard. One of the reasons I like it. Dozens of prototypes and weeks of development went into creating, testing and refining designs.

Depending on how hard you blow, the whistle is tuned to B6 & C#7. The tone is sharp, full, distinctive and a bit uncomfortable. Unlike many 3D printed whistles, this one works with low and high pressure blowing. Fair warning: it is very loud. 118db - 120db. For comparison, a rock and roll concert can be 85lb-100db. Rolling Stones and heavy metal concerts a bit louder. So, be careful how and where you use any whistle and always be aware of how close you are to others when using it. Whistles may be a great warning or signaling tool, but use them responsibly.  Pro tip: If you whistle often, ear plugs are a good idea.

Other variations may be added in the future and I reserve the right to make this thing better in any way anytime I want.

Printing

Printers used for testing Prusa XL, Prusa Mk4s, Prusa Mini, Bambu X1C, Bambu Mini. There are no reasons any well tuned modern printer won’t print whistles.

Basic Settings

• Rafts: No

• Supports: Use included models that have dedicated supports

• Resolution: .15 or .16 depending on your slicer

• Infill: 15-20%

• Use a .4 nozzle. Smaller nozzles are not needed.

• Slow speeds down. Particularly first layers, outer walls, and top surfaces.

This model has a major overhang just inside the air entrance that needs support. It's a difficult area to paint supports so I've included model versions with custom supports created in CAD. I recommend using these versions with SUP added to model names. If you prefer an old school approach, models without dedicated support are also included. 

Printing Techniques

Printing small 3D models requires a different approach. Because these models have a lot of vertical mass for their small size and a tiny contact area they can easily get knocked off the plate. So, I recommend the following…

• When printing small models start with a clean plate

• Slow speeds down. When printing small items, I slow down first layers, top layers, and outer walls. On small items, I usually run first layers at 30mm to insure a perfect first layer.

PLA

The model was designed to be printed with inexpensive PLA filaments. On a project like this you can  use left over spools with whatever filament you have around to print lots of whistles to share.  Best to stick to regular PLA and not use filaments with added materials. IE carbon fiber, glitter, etc. Also avoid soft filaments like silks and some mattes filaments as they’re more prone to stringing. On this project, it’s a good idea to dry your filament before printing. Wispy strings often cause a whistle to not work. PETG certainly works but it is even more prone to stringing. Drying before printing in PETG is even more critical.

The included 3MF files contain recommended print settings. Note that Prusa, Orca, Bambu and Cura slicers can open these same 3MF files and print settings will be included.

Whistle Problems

Turns out 3D printing any whistle can be challenging — particularly small whistles. I tested over a dozen available models before deciding to create my own. Some problems are related to design. Many us are 3D printing issues: air leaks, stringing, retraction settings or filament issues.

Wispy strings inside the sound chamber or in the window/fipple path can interfere with sound creation and projection. Stringing is often a symptom of wet PLA filament. If you’re able to start by drying your filament. The next adjustment you can make is to optimize printer retraction settings and to run retraction tests. Look for YouTube videos to help you test and adjust temperature and retraction settings for your particular printer. Next, make sure nozzle temperature is just right for the filament you’re using. To prevent air leaks, layer-to-layer adhesion must be perfect. A slight clog in your nozzle can create gaps between layers. Any air leak in the sound chamber can result in whistles not whistling.

Always test print first

Print out a single whistle to make sure it works well for you before committing to 10-50 at a time. What you're looking for is a full, resonant sound under low and high pressure blowing. No airiness. These whistles should deliver a crisp, sharp sound with little blowing pressure. If your printer is not well tuned or you have filament problems and your whistle doesn't whistle try these other changes: scale the model to 105 percent, change layer height, or adjust filament temperature. I have often found that different filaments sometimes give different results. When changing filaments I run a test before committing to large runs. I’ve printed almost a 1K so far and get best results by using simple, basic high quality filaments. If you have a problem, try a different filament. That might be enough Again, print single whistles until your settings are dialed in before committing to production.

Test every whistle

You never know if a whistle works until you try it. So, like ACME in the UK who have been making whistles since 1870, I test every whistle. Rather than blow and pass along germs I use a bulb-type camera lens blower. Simple and it works great.

Remember: Make lots of whistles and share with your community and protestors.

Related Models

PEACE Pins https://www.printables.com/model/1594356-peace-pins

NICE Whistle 1...https://www.printables.com/model/1493196-nice-whistle-1
NICE Whistle 2...  https://www.printables.com/model/1573093-nice-whistle-2
PROTEST Whistle... https://www.printables.com/model/1575106-protest-whistle
NO KINGS Collection... https://www.printables.com/model/1337550-no-kings-collection