PROJECTTINKER
[ 10 ]lab · simulations

Gear train / planetary calculator

Spur pairs and compound trains, or a planetary set from tooth counts and which member is fixed - ratio, direction, output speed and torque, checked against the meshing and assembly conditions, plus pitch diameters and centre distance from the module.

lab · sims · gears

Stepper torque/speed →Pull-out torque curve. Battery / power budget →Duty cycle to runtime. Thermal →Junction temperature and margin. Circuit basics →Ohm's law, dividers, LEDs, RC.

The train [ live ]

—ratio
—output speed
—output torque
—efficiency
—meshing geometry
—assembly (equal spacing)
—pitch diameter (sun / first)
—pitch diameter (ring / last)
—centre distance

Kind

Planetary

Stages

Sizing & input

Assumptions and limits. Ideal involute gearing at the stated module on every mesh - no backlash, no profile-shift correction, and (for the planetary geometry check) equal module on sun, planet and ring, which is what makes Zr = Zs + 2Zp the exact meshing condition. Efficiency is a flat per-mesh number, not a function of load or speed. The planetary ratio always uses the conventional input/output pairing for whichever member is fixed (sun in / carrier out with the ring fixed; carrier in / ring out with the sun fixed; sun in / ring out, reversed, with the carrier fixed) - the same relationship run the other way just inverts the ratio.