Motor Power Calculator
Calculate KW for Hoist, Cross Travel (CT), and Long Travel (LT) motions using inertia and friction physics.
Required Motor Power
Calculation Methodology
Hoist Formula
The hoist motor must overcome gravity for the load plus the hook block assembly.
P = (F × v) / (1000 × η)
- F (Force): (SWL + Hook Weight) × 9.81 m/s²
- v (Velocity): Speed in m/s
- η (Efficiency): Gearbox efficiency (typ. 0.85)
Travel Formula (CT & LT)
Travel motors must overcome rolling friction AND inertia (acceleration force). Inertia is often larger than friction.
P = (F_total × v) / (1000 × η)
μ × Total Mass × 9.81
Overcomes wheel bearing & flange friction.
Total Mass × (v / t)
Force required to accelerate mass from 0 to speed v in time t.
Duty Cycle (CDF) & Efficiency
Energy loss occurs in gears, bearings, and ropes. Lower efficiency requires higher motor power.
- Helical/Spur Gears: 0.85 - 0.90
- Worm Gears: 0.60 - 0.70 (Inefficient)
Motors aren't rated to run continuous 24/7. Select based on starts/hr.
- S3-40%: Standard workshop use.
- S4-60%: Heavy production/Steel plants.
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