Herringbone Gear Generator by Oryhara | Download free STL model | Printables.com
Manufacturing Tools – Niklas Pöllönen
GitHub - NicoSchlueter/HelicalGearPlus: Generates straight, helical and herringbone external, internal and rack gears as well as non-enveloping worms and worm gears
Helical Gear: What Are They? How Do They Work? How to Manufacture Them?