3d-printed whistle head: strengthening lower octave

[Alaskamike]

Naxrax - do you have the print file (STL) posted anywhere? I'd love to try it out on my printer. I've been pretty disappointed with other whistle prints.
Thanks.

Mike

[Narzog]

Naxrax - do you have the print file (STL) posted anywhere? I'd love to try it out on my printer. I've been pretty disappointed with other whistle prints.
Thanks.

Mike

A thing to keep in mind is 3d prints arent overly mouth safe. For assorted reasons. The print lines are bacteria hotspots, sketchy things in the filament, what type of filament, etc.

From my past trying to 3d print whistle heads, my best success was not printing the lip, and having that be part of your tube. Then you can still get a good quality lip.

[MadmanWithaWhistle]

Naxrax - do you have the print file (STL) posted anywhere? I'd love to try it out on my printer. I've been pretty disappointed with other whistle prints.
Thanks.

Mike

A thing to keep in mind is 3d prints arent overly mouth safe. For assorted reasons. The print lines are bacteria hotspots, sketchy things in the filament, what type of filament, etc.

From my past trying to 3d print whistle heads, my best success was not printing the lip, and having that be part of your tube. Then you can still get a good quality lip.

This is more for those following the thread than the OP, but as an expert in the fields of both microbiology and 3D printing, I'd like to contribute that there's a lot of misconception and half-remembered information surrounding the "safety" of 3D printed parts.This stems from several factors:

• Resin vs FDM printing

• Misunderstanding of "food safe" regulations

• Post-prossessing of 3D printed parts

• Material data reporting

Resin vs FDM printing
First of all, the biggest source of "safety" information concerns the resin feedstock for photopolymerization. This is either a laser beam or a UV light through a selectively transparent screen hitting a pool of liquid resin, and hardening it at the point the light hits it. Because this method uses a relatively low-energy method to create a large physical change in the feedstock, the feedstock is pretty reactive. In general, greater reactivity of a substance tends to mean greater safety measures are required to handle it safely. In this case, the liquid resin is comparable to the two-part epoxy you can get at the hardware store - you want to wear gloves when you work with it, and work in a well-ventilated area.

However, these safety concerns *only* apply to uncured or partially-cured resin. You can touch and use fully-cured resin prints like any other household object, although food contact is not recommended for reasons I'll get into below.

FDM printing carries none of this distinction - it's essentially just a very precise hot glue gun, melting a polymer filament and extruding it. Aside from ventilating the area during printing, there really are no reactivity concerns between the filament and the final part, and the material safety is determined solely by the ingredients in the filament.

Misunderstanding of "food safe" regulations
Most people conflate "food safe" with "safe to put in your mouth" i.e. "if it's not food safe, it's not safe to put in your mouth." This is where the majority of misconceptions regarding 3D printed instruments comes from in my opinion. "Food Safe" as defined by the US FDA is an incredibly high standard that specifies, among other things, a certain quantity of the material you must be able to ingest without harm! It also includes surface requirements, heat stability, how easily bits of the material flake off, and many more points. There are very few if any whistles on the market that meet these requirements - the lead content of free-machining brass alone disqualifies it as food-safe, most tonewoods and finishing oils are not approved for food use, and unless plastic whistle manufacturers are doing QA testing on their plastic feedstock, their products would also fail a "food safe" certification.

This doesn't mean that brass and wooden whistles are dangerous - they're not! "Safe to put in your mouth" does NOT equal "Food Safe."

Post-processing of 3D printed parts
Another common statement regards the layer lines, especially of FDM prints. The FDM process does not create perfect fusion of the layers - the slight inconsistencies in extrusions appear as lines perpendicular to the vertical axis of the part, and are essentially "peaks and valleys" when viewed under a microscope. It's true that bacteria can more easily gather in rough surfaces, but this is no less true of the grain on a wooden whistle or the joints where separate parts of any number of instruments are held together. If you've ever pensively nibbled on a piece of jewelry or sweatshirt drawstring, it's the same thing. Concerns arise when the object's primary purpose is either preparation of food (again, stringent requirements above), or insertion into parts of the body prone to infection. The mouth is one of the parts of our body best guarded against infection - when was the last time you got thrush from playing a whistle? The real-life concerns regard people trying to print their own dishes or sex stuff.

Finally, the raw surface of 3D prints is not always left as such - vapor polishing on compatible materials, or application of a clear coat seals the surface and makes the issue moot anyway.

Material data reporting
For those concerned about "sketchy things in the filament," well, unless you're buying nameless feedstock off Amazon or AliExpress, you can ring up the manufacturer for their Material Data and Safety Sheet, (or usually just download it from their website) and see if there's anything really reactive in there. Quality manufacturers will usually advise you of this anyhow! I would be a little more concerned about squishy/stretchy materials like TPU, simply because most commonly used plasticizers (like bisphenol-a) have more documented health concerns regarding their use in food-contact applications, but again, unless you plan to frequently prepare meals or penetrate yourself with it, the few square millimeters of skin contact while playing an instrument is really not a concern. Resin prints can be the exception to this - depending on the formulation of the resin, some allergenic compounds may remain in the finished print, so putting them on mucous membranes may result in a slightly increased chance of mild irritation.

This is really no different than cocuswood being an iffy material, though. In reality, there is no hypoallergenic tonewood - all are mildly irritating with enough contact, even blackwood or mopane (usually it takes breathing in the trace dust in the workshop to discover that!). I've also never heard of anyone requesting the ingredients in Generation or Feadóg's plastic feedstock, either, or the specific alloy of brass used by Burke or the gazillion Sindt knock-offs.

That said, "making you feel better," is still a perfectly valid reason for design revision - it's a simple matter to just model in a reduction to the mouthpiece and print a mold for a little silicone sock you can fit up to the part with an index. Use "body safe" aka platinum cure silicone and you're good. I do encourage folks to be aware of the nuances in food safety and 3D printing, and avoid making sweeping statements regarding the field, though.