gyro mult blade rotor heads

Roger

A simple two bladed teetering rotor system works quite well.

Our minds and common sense tries to convince us twice as many blades would be twice as good.

I think we all go down that road for a moment or two when we become interested in Rotary wing flying. The reality is there is not enough advantage to adding extra blades to make it worthwhile.

On a three , four , or five blade system , you will have to hinge each blade so it is free to flap up or down , a blade that is allowed to flap freely up and down will speed up and slow down as it changes position. To accommodate this you require another set of bearings and hinges to let the rotor blade move forward and backward every revolution.

Each individual blade will speed up and slow down a bit too much each time so you will need a damper on each blade to regulate the movement.

It can be done , and has been done in the past. A multi blade rotor system can be very smooth and almost vibration free.

Will it fly any faster? Not likely.

Is it easier to design and build? No.

Will a multi blade rotor take up more or less room in the hanger? More.

How many bearings , bushings , pivot points on a three blade rotor? Six

How many bearings, bushings , pivot points on a two blade teetering rotor? One.

What are the advantages? Very few. Especially for the home builder and experimenter.

Best wishes Roger. By the way , I love multi blade rotors. If I had the budget I would have one.
 
An Apache tail rotor. Two teetering rotors 9ft diameter.
Looks to have elastomeric teeter bearings.

Keep the cone angle down, use delta three to reduce or eliminate flap.
Four blade gyro rotor?
 

Attachments

  • apache tail rotor.jpg
    apache tail rotor.jpg
    42.2 KB · Views: 1
Top