v30 (v29) Whistle - Compact Edition

prusaprinters

<p>This is a redesign of Goury's v30 whistle (thing:2783665) which was itself inspired by jzisa's v29 whistle (thing:1179160).</p><p>After printing the v30, I realised that a big portion of the internal volume did not have any sound-making function - it seemed to be there for aesthetics and to put the keyring hole. It also had some features that are hard to print on FDM printers - namely the curved top (that needs a very low layer height if you want it to come out not looking blocky) and the curved inlet holes (that curl up from overheating unless you print really slowly or you have a really well-tuned profile).</p><p>I therefore present - the v30 "compact edition". This is a whistle that sounds similar to the v30, but is about a third of the size, and uses 40% less material. Here's a comparison (with 0.2mm layer height and 0.4mm extrusion width):</p><ul><li>v29: 13.83 grams</li><li>v30: 8.76 grams</li><li>v30 Compact Edition: 4.94 grams</li></ul><p>Details of the changes are listed in the section below. I've attached the .stl file for printing, the source .f3d file for editing in fusion, and .step file for editing in other CAD packages if desired.</p><p>Released under GNU GPL license same as the original v30 whistle.</p><h3>Print Settings</h3><p><strong>Printer Brand:</strong></p><p>Anycubic</p><p><strong>Printer:&nbsp;</strong></p><p>Kossel</p><p><strong>Rafts:</strong></p><p>No</p><p><strong>Supports:&nbsp;</strong></p><p>No</p><p><strong>Resolution:</strong></p><p>0.08mm to 0.2mm</p><p><strong>Infill:&nbsp;</strong></p><p>15% honeycomb</p><h3><br>How I Designed This</h3><p>All the edits were done with Fusion 360. Here's a list of the changes:</p><ol><li>Removed the back of the whistle (where the keyring hole was) - leaving just enough material to have a 1mm wall around the resonant cavity. The result is a ~20 mm saving in overall length.</li><li>Cut away about half the top, resulting in a ~10mm reduction in overall height</li><li>Added a flat top of 1mm thickness (to match the bottom plate thickness). This is much easier to print and will look good even at normal layer height of 0.2mm.</li><li>Added a keyring hole in the back side (in one of the remaining non-functional spaces).</li><li>Redesigned the front to have rectangular inlet holes. These are easier to print becuase the top is a straight bridge that the printer does in one motion (no overhangs). Moreover, I sized the holes to give a slightly reduced inlet area. This makes the whistle slightly harder to blow, but makes it start to whistle (rather than just making a "whoosh" sound) at lower airflows. It also makes it easier to control the volume based on how hard you blow.</li><li>Redesigned the internal passages for smooth flow with the new inlet shape and to maintain a divergent cavity until the airflow gets to the flow divider. All overhang angles are 45° for easy printing without supports.</li><li>Filleted and rounded external profiles to save even more material.</li></ol><p>Category: Sport &amp; Outdoors</p>