Calculadora de Passo e Deslizamento de Hélice ⚙️
Calcule o percentual de deslizamento da hélice e risco de cavitação. Insira passo, diâmetro, RPM e relação de transmissão.
Como usar a Calculadora de Hélice
Insira o passo da hélice (polegadas), diâmetro, RPM do motor, relação de transmissão e velocidade GPS real.
Deslizamento de 5–15% é normal. Acima de 25% indica possível sujeira no casco ou dano na hélice.
O risco de cavitação é baseado na velocidade da ponta (π×D×RPM eixo/12). Abaixo de 9.000 ft/min é seguro.
FAQ
What is propeller slip and how is it calculated?
Propeller slip is the difference between theoretical speed (pitch × RPM / gear ratio / 1215.2) and actual GPS speed. Slip % = (theoretical − actual) / theoretical × 100. Normal recreational boats run 5–15% slip.
What causes high propeller slip?
High slip (> 25%) is caused by hull fouling, propeller damage, incorrect pitch for load, or heavy displacement. Clean hull regularly, inspect prop blades for nicks, and consider re-pitching.
What is cavitation and how does tip speed affect it?
Cavitation occurs when propeller tip speed creates low-pressure bubbles that implode on the blade surface, causing damage and loss of thrust. Tip speed = π × diameter × shaft RPM / 12. Below 9,000 ft/min is safe; above 14,000 ft/min is critical.
What is the ideal propeller slip for recreational boats?
5–15% slip is ideal for most recreational planing boats. Displacement hulls typically run 10–20%. Racing props can achieve 3–8%. Slip outside these ranges warrants inspection.