GenerateSTL

What is GenerateSTL?

GenerateSTL is a free browser tool that builds functional parts from sliders and number fields and exports them as STL. The gear editor handles spur, helical, herringbone, internal, rack and 90 degree bevel gears with involute teeth, and a planetary mode builds a matching sun, planets and ring together. The screw editor makes threaded rods, screws, nuts and washers from metric presets (M2 to M20, coarse and fine) or custom sizes, with five thread profiles and several heads and drives.

The other four editors make print-in-place sliding bearings with two or three rings, rectangular boxes with a lipped lid, vent grilles with slot, hex or circle openings, and a pegboard on a fixed 24 mm grid with matching printed screws. Downloads are binary STL files, or a ZIP when a set has several parts. Each file stores its settings in the STL header, and the site says you can drop an old file back in to restore the recipe.

No account is needed. The geometry engine is published on GitHub under the MIT license, though as of September 2026 that public copy had a single commit and did not include the planetary mode. The site launched in late August 2026, and there were no user reports on printed fit as of September 2026. It suits makers who know which module, thread or clearance they need.

What you can make

• Spur, helical and herringbone gears
• Bevel pairs, racks and planetary gear sets
• Screws, nuts and washers
• Print-in-place sliding bearings
• Storage boxes with lids
• Vent grilles and pegboards

How to use GenerateSTL

1. Open the studio and pick gears, screws, bearings, boxes, grilles or pegboard in the sidebar
2. Start from a template or preset, for example M6 coarse or the 22/8/7 mm bearing
3. Drag the sliders or type exact values, then check the preview and any warnings
4. Click Export STL and print a small fit test before the final part