Elysia Tools
Navigation
Workflow Playbook
Screen a gear, belt/pulley, chain/sprocket, torque, or spring-rate calculation by matching the transmission type to the known quantities. Treat every result as preliminary, not a certified design.
Hubs
This workflow is for preliminary screening of machine elements, not for certifying a finished design. First identify whether the question concerns a meshing gear pair, a belt drive, a chain drive, a force and lever arm, or a cylindrical helical spring. Then record the quantities you actually know instead of filling missing inputs with assumed values.
Use gear-ratio-calculator when driver and driven tooth counts define the gear relationship; add driver speed when driven rpm is needed. Use gear-module-calculator when the input is pitch diameter with tooth count or circular pitch. For a belt drive, belt-pulley-speed-ratio uses driver and driven pulley diameters and can add driver rpm for driven speed and belt linear speed. For a chain drive, chain-sprocket-ratio uses sprocket teeth and can use driver rpm plus chain pitch to obtain chain speed.
For a force-transmission question, use torque-calculator only after identifying two known values among torque, force, and lever arm and the angle between the lever and force. For a cylindrical helical spring, use spring-rate-calculator with shear modulus G or a material preset, wire diameter, mean coil diameter, and active coils.
Record the inputs, roles, units, and displayed result. Recheck the relationship with a simple case: a larger driven gear, pulley, or sprocket should reduce output speed when the driver is smaller, while the torque angle should be interpreted through the perpendicular force component. Watch for swapped driver/driven labels, mixed diameter units, a missing optional speed or pitch, a wrong angle, or a spring geometry that does not match the assumed model.
The output is preliminary calculator support, not a certified design. Friction, material behavior, fatigue, safety factors, tolerances, heat, duty cycle, interfaces, and applicable standards require engineering review before a component is selected, built, or approved.
Workflow playbook
Sketch the driver and driven sides or the spring/force geometry, name every known quantity, and choose one consistent unit system. Treat the six calculators as alternative paths rather than entering guessed values into every tool.
For a meshing pair, use gear-ratio-calculator with driver and driven teeth, and add driver speed only when output rpm is required. Use gear-module-calculator instead when pitch diameter plus teeth, or circular pitch alone, is the known input path; record module, circular pitch, and any returned diameter or addendum.
Choose belt-pulley-speed-ratio for pulley diameters and optional driver rpm, or chain-sprocket-ratio for sprocket teeth. Add chain pitch only when the chain linear speed is part of the question, and retain the ratio, driven speed, or linear speed with its units.
Choose gears for meshing tooth counts, a belt drive for pulley diameters, a chain drive for sprocket teeth and optional pitch, torque for two known values among torque, force, and lever arm plus the angle, or spring rate for a cylindrical helical spring with G/material and coil dimensions.
Use gear-ratio-calculator when driver and driven tooth counts are known, adding driver rpm when output speed is needed. Use gear-module-calculator when pitch diameter and tooth count, or circular pitch, are the known quantities.
Use belt-pulley-speed-ratio for driver and driven pulley diameters, with driver speed for driven speed and belt linear speed. Use chain-sprocket-ratio for sprocket teeth; add driver speed and chain pitch when chain speed is needed.
Use torque-calculator when two of torque, force, and lever arm are available and the force angle is known. Use spring-rate-calculator when shear modulus G or a material preset, wire diameter, mean coil diameter, and active coil count are available.
Use torque-calculator with the two quantities that are known among torque, force, and lever arm plus the angle. Use spring-rate-calculator with G or a material preset, wire diameter, mean coil diameter, and active coils. Check the result against the intended load and label it preliminary; friction, material, fatigue, safety factors, tolerances, heat, and applicable standards still require engineering review.