January 7, 2026
Tooth be told: drama gears up
Show HN: Free and local browser tool for designing gear models for 3D printing
A free click-to-make gear app has HN buzzing—dads swoon, gear nerds nitpick
TLDR: A free browser tool lets people design gears for 3D printing, sparking excitement and a wave of demands. Commenters want auto‑matched companion gears, bevel/rack types, and STEP exports for CAD; one hot take slammed FreeCAD, and others asked if the printed parts actually mesh—practical and playful energy alike.
Hacker News went full gear fever over a free, local-in-browser tool that lets you design 3D‑printable gears with a click. The feel-good moment arrived fast: one parent gushed that “my son loves gears” and is now plotting a family 3D printer purchase. Then the drama teeth came out. User kypro tossed a spicy grenade—“FreeCAD kinda sucks”—and immediately asked for fancier toys: bevel gears and racks. Others loved the slick simplicity but wanted proof it actually works in the real world: blorenz pressed for how well printed gears actually fit and mesh, and what libraries power this wizardry. The hottest request? Paired gears that auto-match. Leptons warned that if you make skinny teeth with big gaps, your partner gear must fill those gaps—or nothing will spin. Cue the “tooth wars.” Meanwhile auxym showed up with a power‑user demand: STEP export, a standard CAD file format, so folks can import the gear into their design software and add custom hubs like pros. Between the mathy sliders and export dreams, the thread felt like a mash‑up of maker joy, dad‑mode wholesomeness, and a mini turf battle over CAD tools. Verdict: the community is hooked, but they want meshing magic and pro‑grade exports, stat.
Key Points
- •NEO GEAR BTW is a free, local, browser-based parametric gear generator for 3D-printable gears.
- •Users can set core parameters such as teeth count, module, pressure angle, helical angle, shaft bore properties, and face width.
- •The tool calculates derived dimensions including pitch, outer, root, and base diameters; tooth height; and circular pitch.
- •An example configuration shows Module 2 mm, 32 teeth, 20° pressure angle producing a 64.0 mm pitch diameter and related dimensions.
- •The interface includes an option to export the generated gear model.