Pulley & Wheel-Axle

Compute mechanical advantage and required effort for wheel-axle, n movable-pulley systems and differential (chain) hoist.

Inputs

Formula

Wheel-axle MA=R/r; n pulleys MA=2n; differential MA=2R/(R−r); F = W/MA
W机械增益 = 支承绳段数
Pulley & Wheel-Axle schematic

How to use

  1. Fill in Mechanism, Large radius R, Small radius r, Load W, Pulley count n in the Inputs section (watch the unit on each field).
  2. Click Calculate; the tool evaluates the formula shown above.
  3. Read Mechanical adv. MA, Effort F in the results area.
Formula notesPulley system mechanical advantage = number of rope segments n supporting load; ideal pull F = W / n.