Tube Whistle

thingiverse

WARNING: This whistle can produce sound at the level of a leaf blower, rock concert or chainsaw. Hearing protection is recommended. This whistle makes noise based on the same concept of making sounds by blowing over a bottle opening. It has 4 different depth "tubes", each creating a different frequency sound. They combine to make a very loud noise in a small package. The design includes a hole for a keyring so you can always have it handy in case of emergency. Update 1: Due to some printing artifacts, I found it difficult to blow through the whistle (the output slot was too constricted), so I enlarged it (Whistle_V2_10.stl). I got higher decibel sound pressure, but actually find it not restrictive enough (cannot blow very long), so I'll be making a 3rd version with the slot in between the first two versions. I also added some bumps on the mouthpiece, so that it can be held in your mouth with your teeth — so you don't spit it across the room while trying to max out the Db meter... Update 2: The latest version — Whistle_V3_12.stl — has a more restricted airflow exit than V2, therefore increasing the air velocity (same volume of breath over same amount of time, through smaller opening equals higher velocity), and is giving better results. I think I can get the opening even smaller for more improvement... Update 3: Ok, I like the results of version 4, Whistle_V4_13.stl. It consistently hit 112.7dB, and I got as high as 113.2dB (see meter details). Next step, make a 3- and 2-tube version; smaller to be more convenient in your pocket or on your keychain. We'll see if they remain as loud. https://youtu.be/FM8kXS_-W4khttps://youtu.be/_c5vfjrDvrQ Update 4: I added 3-tube and 2-tube versions; they're not quite as loud though. I'll probably try a 5-tube, and see if I can get any more volume out of it... I also uploaded another version of the 4-tube — it's a single solid (someone reported difficulty using the existing .stl files (the mouthpiece didn't show/print); if you have that problem try Whistle_V4_one_solid. Update 5: I made a 6-tube whistle (6-Tube_Whistle.stl); it's not quite as loud as the 4-tube, and is almost too wide for my mouth. So far, the 4-tube still holds the dB record for these whistles. Update 6: I tried another variation; two rows of 5 tubes. 10-Tube_Whistle.stl Still about the same volume; no significant change in volume one way or the other. Here is a video of all whistle measurements: https://youtu.be/zMTjigL1g2Q Update 7: Version 5 — I made some refinements to the shape — moved the airflow exit slot closer to the tubes, and enlarged the tubes slightly. It now whistles with much less blowing effort (it does not require as much air velocity). I only modified one variant; the 3-tube one; the new file is 3-Tube_Whistle_V5.stl Up to this point, I was printing .25mm layers. With the enlarged tubes, that resolution would only produce one layer between the tubes (they print horizontally), so for the V5 whistle, I used .1mm layers. Update 8: Using the Version-5 design modifications (larger diameter tubes, etc.), I made a 9-tube variant. I was hoping that the offset tubes would yield better volume based on the airflow over the second row of tubes not being directly behind the first row. It really didn't make much difference; it's still the same average dB levels as the others. Update 9: I created a variant having a "pea chamber", to have that typical sports whistle sound. You must print the pea Pea.stl first, and drop it into the pea chamber of the whistle 4-Tube_Pea_Whistle.stl while the whistle is printing, once it has printed enough layers (so the print head doesn't hit it). It will be enclosed when the print is finished. The top "hole" in the pea chamber will be "closed" by a single bridging layer, which should be cut away. It should be printed with .1mm layers. Update 10 (17-Oct-2015): Tried a totally new design shape using the same tube principal...after two failed designs, the 3rd one worked... the result? A 3-tube "Pyramid" whistle. 3-Tube_Pyramid_17.stl It's the quietest of all these tube whistles (but still loud), but looks cooler! Printed with .25mm layers. (Working on a 9-tube variation of this...stay tuned). Update 11 (18-Oct-2015): Finished and printed 9-tube "pyramid" design 9-Tube_Pyramid_21.stl; it's not even as loud as the 3-tube pyramid, so I probably won't pursue this pattern further. Update 12 (24-Oct 2015): Ok, I had to complete the pyramid whistle set with a 6-tube version 6-Tube_Pyramid_20.stl. I improved the airflow slots, and got a decent volume out of it (between the 3-tube and 9-tube pyramids). Print Settings Rafts: No Supports: No Resolution: I printed the early versions with .25mm layers. The later versions, with the larger diameter tubes, need to be printed with .1mm layers due to the thin separation between the tubes. Infill: Doesn't really matter; most of the print are thing walls which will be solid. I use 50% infill. Notes: When printing the pea whistle, print the pea first. I used "spiral vase" mode, which is a single permitter, and no infill, resulting in a hollow sphere. It actually broke in half while blowing the whistle! (but it still works; the halves are still too big to fall out). I would recommend 2 shells and 0% infill. I'm not sure if a solid pea will be too heavy; probably not; I'll probably print another one and try that. The pea must be dropped into the pea chamber of the whistle once it prints about 10.5mm high, and will be permanently encased in the chamber once the top layers print. In order to avoid a free-floating surface, the top (when printed) has one layer that completely covers the top; that's the bridging layer; the subsequent layers of the top, only have the "ring", leaving only the bridging in the center hole. That bridging should be removed after printing, so there is a hole on each side.