Propellersteigung & Schlupfrechner ⚙️

Propellerschlupf und Kavitationsrisiko berechnen. Steigung, Durchmesser, RPM und Übersetzung eingeben.

Anleitung zum Propellerrechner

Propellersteigung (Zoll), Durchmesser, Motor-RPM, Getriebeübersetzung und GPS-Geschwindigkeit eingeben.

5–15% Schlupf ist normal. Über 25% deutet auf Bewuchs, Beschädigungen oder falsche Steigung hin.

Kavitationsrisiko basiert auf Blattspitzengeschwindigkeit (π×D×Wellen-RPM/12). Unter 9.000 ft/min ist sicher.

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.