Fit the wheels, then match the output speed.The motor and shaft positions are fixed. Choose a wheel below and swap its tooth count. Meshing wheels must touch at their dashed pitch circles; they turn in opposite directions. Coaxial wheels share a shaft and turn together.
Pass all checks: every output stage connected, no overlapping wheels on the same layer, correct output speed and direction, and no more than the tooth budget. Try the first job with a 24-tooth output wheel.
Motor
Required output
Actual output
Total teeth
How the teeth work · source & limits
A wheel with N teeth has pitch radius N/2 in our unit module. Meshed centers must be separated by the sum of pitch radii. Their angular speeds have opposite signs and ratio −N₁/N₂. Stacked gears share angular speed; their different radii let multiple reductions multiply.
Colored layers separate coaxial gears in depth. The drawing offsets the small shaft label, not the gear center. This is an ideal kinematic model: no backlash, friction, elastic teeth or torque dynamics. Tooth budgets count all wheels including the fixed motor. Saved progress stays in this browser.
Involute outlines, mesh detection, tooth-phase alignment and angular-speed propagation adapted from Gearworks by Artem Baranovski (MIT, September 2026; 0 stars observed). Original missions/interface and GPT material atlas. License.