• Alternative B; Planetary (Epicyclical):

• Rotor Reduction + Propeller - Primary & Power Splitter: Spider gear set or planetary gear set. This may also be primary reduction to rotors.
• Spider Gears: with inline shaft going to propeller.
• Hover ~ Prop locked will give 2:1 reduction to rotor.
• Hypothetical ~ Rotor locked will give 1:1 ratio to prop.
• Cruise ~ assumed ratio between rotors and prop rpm is 10:1 will give 11:1 reduction to rotors and 11:10 reduction to prop
• Planetary Gears: with planet holder coupled to engine, sun going to propeller and ring (annulus) coupled to rotor reducers.
• Planet carrier is coupled to engine. Ideal speed is 5,800 rpm. Teeth in planets = 15.
• Sun is coupled to propeller. Desired speed is 5800 rpm.? Teeth in sun = 42.
• Ring is coupled to Rotor reducers. Planetary output speed with propeller locked is 9,183 rpm and during cruse it is 5,800. Teeth in ring = 72.
• Ratios:
• Sun to Planet carrier to Sun = 2.7:1
• Planet carrier to Ring = 1.6:1
• Sun to Ring = 1.7:1
• Hover Speeds:
• Planet carrier [from Motor] = 5,800 rpm
• Sun [to Propeller] = 0 rpm
• Ring [to Rotors] = 9,183 rpm
• Cruise Speeds:
• Planet carrier [from Motor] = 5,800 rpm
• Sun [to Propeller] = 5,800 rpm
• Ring [to Rotors] = 5,800 rpm
• Look into buying a stock one and then modifying it: If this ratio of 2.7 to 1 can be bought.
• The gears will probably have to be helical due to the high speed; and also to keep the weight down.
• Take the gears and put them in a custom gearcase?

• Alternative A; Spider:
• Hover: 1:2 motor to rotor speed up.
• Cruise: 1:1 motor to rotor & 1:1 motor to propeller.

• Alternative B; Planetary:

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