Two modes for a single-stage epicyclic set. Common lets you pick two gears, solves the third, validates spacing/collisions/GCD/hunting, and can suggest the nearest valid trio. Search flips the task: for a target ratio, it scans tooth ranges under the same rules to find matching sets. Either way you can animate the scheme, tweak pressure angle, clearance, backlash, display fidelity, and export SVG/DXF. Have fun.
Gear geometry constraint Zr = Zs + 2·Zp is enforced automatically and shown live as you adjust tooth counts.
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