GearStudio: free planetary gear generator and CAD exportGearStudio is a free browser tool for designing involute planetary (epicyclic) gear sets, spur or helical, and exporting them to CAD. Pick tooth counts and a module or diametral pitch, and it computes true involute tooth flanks with trochoidal root fillets, checks that the set will assemble, animates it in 2D and 3D, rates the teeth for strength, and exports files ready for CNC machining, laser cutting or 3D printing.

Planetary gear ratio calculator for any choice of fixed and input member

Spur and helical gears in metric module or inch diametral pitch, with pressure angle, profile shift and backlash

Undercut, contact ratio and assembly checks: coaxial, equal spacing and planet clearance

AGMA 2001 bending and contact stress with AGMA 908 J and I factors, planet load sharing and design factors

Export to STEP, STL, DXF and SVG

Guides: planetary gear ratio calculator, planetary assembly conditions, undercut and profile shift, module vs diametral pitch, gear stress analysis (Lewis and AGMA), STEP vs STL vs DXF for gears.The design app itself runs in the browser with JavaScript enabled; the guides above are plain pages.