Rotors

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kjhsscioly
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Re: Rotors

Post by kjhsscioly » April 10th, 2011, 7:10 pm

they gave plenty, so I just salvage it... besides, I will never have use for 30 grams of ballast...

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illusionist
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Re: Rotors

Post by illusionist » April 20th, 2011, 7:38 am

http://www.indoorfreeflight.com/heli/peteheli.gif
In that design, the plans show the rotors "v" up. Is there a reason for the v-shape of the rotors?
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Re: Rotors

Post by wlsguy » April 20th, 2011, 8:08 am

The V shape will increase stability.
As the helicopter starts to wobble, the lower blade will become more efficent and put it back on the correct axis.

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kjhsscioly
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Re: Rotors

Post by kjhsscioly » April 20th, 2011, 9:57 am

How would you build that to be sturdy and light out of balsa? It seem like you would make each side seperate, and for a spinning airfoil, that sounds delicate.

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Re: Rotors

Post by illusionist » April 20th, 2011, 10:31 am

The way I would do it is to build it just like a standard rotor, and then break the spars in the middle, angle them upward, and then glue them. Yes it would be delicate and somewhat difficult to build consistently, but it may be worth it. I'll have to give it a try sometime.
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kjhsscioly
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Re: Rotors

Post by kjhsscioly » April 22nd, 2011, 10:24 pm

wouldn't you have to build it so the top spar is shorter than the bottom, and separately? breaking or cutting them seems too delicate and inconsistant.

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Re: Rotors

Post by wlsguy » April 23rd, 2011, 12:33 pm

Our team helicopters last year used the V configuration. (dihedral)
The top rotor had less than the bottom to try and balance the lift between the rotors.

From what I remember, stability was better at the end of the flight when the torque reduced.
The current helicopters are generally very stable at the higher launch torque and only become "wobbly" at the end of the flight.
Strength was not normally an issue. and I do not remember a case of rotor damage.
We also used a small 6" whisker at the bottom (like the top ones used today).
It prevented the rotor from hitting the ground at landing.

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lucwilder42
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Re: Rotors

Post by lucwilder42 » May 1st, 2011, 9:33 pm

Has anyone had success with rotors that deviate from the kit design? Because the kit rotors arent exactly normal looking blades and it seems like something different might produce better times, something more realistic
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Re: Rotors

Post by thedoctor » May 16th, 2011, 5:50 pm

Would there be any benefit to build rotors similar in design to the propellors from Wright Stuff? What i mean is that on those Ikara props, the chords near the middle of each blade is longer than the chord at the tip. Would it be beneficial to mimic this on a helicopter rotor? (Though it would be tricky to construct something like that.)

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Re: Rotors

Post by lucwilder42 » May 16th, 2011, 6:05 pm

thedoctor wrote:Would there be any benefit to build rotors similar in design to the propellors from Wright Stuff? What i mean is that on those Ikara props, the chords near the middle of each blade is longer than the chord at the tip. Would it be beneficial to mimic this on a helicopter rotor? (Though it would be tricky to construct something like that.)
It defintely would be, but it's a little late in the game to start experimenting with that...
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