Question? What Determines A Good Helicopter Blade

Discussion in 'The Chat Room' started by smakmeharder, Feb 4, 2015.

By smakmeharder on Feb 4, 2015 at 10:51 PM
  1. smakmeharder

    smakmeharder Administrator

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    I have tried blades that look very similar in profile yet fly completely different. I would like to know what attributes are responsible for the following:

    Bite: what shapes determine how aggressive a helicopter blade creates lift. I know airfoil can have something to do with this but some airfoils are more toward the center line of the blade while others are at the leading edge.

    Stability: What characteristic determines how stable the helicopter is at fast forward flight. For example I know that Halos are pretty good at FF flight, and so are rails.

    maneuverability: Some blades roll and flip really well. Others not so well. I am guessing the COG of the blade weight has something to do with this.

    Bigger blades vs Smaller blades on the same helicopter: I dont know why but i am drawn to the biggest possible blade that will fit on a helicopter. It just "FEELS" beter to me..

    Efficiency: What charactoristics make a blade more efficient? Ie: is a particular profile airfoil more suited towards a certain RPM? Some blades mange to provide pop without draining the engine.

    Outer Edge Profile: Does the shape of the outer edge have a big effect?

    All these questions remain unanswered in my head... Does anyone know the answer to some of these questions? Do we have an aeronautical engineer in the house?
     
    smakmeharder, Feb 4, 2015
    #1

Comments

Discussion in 'The Chat Room' started by smakmeharder, Feb 4, 2015.

  • Page 2 of 2
    1. Beaver

      Beaver Well-Known Member

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      Fly bar blades... hmm.... I'll be trying that on my Nano tonight. I just happen to have a set of blades from a coax that will fit.
       
      Beaver, Feb 7, 2015
      #21
    2. smakmeharder

      smakmeharder Administrator

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      The "ONLY" issue i have with FB blades is that on Fast Forward flight they can pitch up for some reason. So if you do a huge inverted loop, your heli can suddenly pitch straight into the ground at full speed! Aint that right @3dmick?
       
      smakmeharder, Feb 7, 2015
      #22
    3. Beaver

      Beaver Well-Known Member

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      They aren't really designed for fast forward in most cases. Isn't most of the lift concentrated towards center of disk to make response faster with fly bar?
       
      Beaver, Feb 7, 2015
      #23
    4. Beaver

      Beaver Well-Known Member

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      Nope, that didn't work well. Excellent lift, lower head speed, poor stability even at hover. 3 axis gyro system not calibrated for those conditions. Going back to stock blades.
       
      Beaver, Feb 7, 2015
      #24
    5. 3dmick

      3dmick Well-Known Member

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      Yes inverted over speed pitch up is a dangerous move lol
       
      3dmick, Feb 7, 2015
      #25
    6. smakmeharder

      smakmeharder Administrator

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      Well at least you gave it a try @Beaver! You never know unless you try!

      And @3dmick, its a very expensive move as well!
       
      smakmeharder, Feb 7, 2015
      #26
    7. Beaver

      Beaver Well-Known Member

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      Experimentation is half the fun.
       
      Beaver, Feb 8, 2015
      #27
    8. smakmeharder

      smakmeharder Administrator

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      Well its how we progress in the real world @Beaver ! We need more of it because the world of CP helis is surrounded by alot of claims/hype!!!
       
      smakmeharder, Feb 8, 2015
      #28
    9. Beaver

      Beaver Well-Known Member

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      I know for a fact, what looks good on paper doesn't always work in the real world. One day I may be able to contribute something useful to this hobby once I catch up with the current technology.
       
      Beaver, Feb 8, 2015
      #29
    10. smakmeharder

      smakmeharder Administrator

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      I think your doing fine @Beaver!
       
      smakmeharder, Feb 8, 2015
      #30
    11. Jeff_Bradley

      Jeff_Bradley Well-Known Member

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      Found this for you mate

      Cyclone Blades Australia


      Sent from my iPhone using Tapatalk
       
      Jeff_Bradley, Feb 9, 2015
      #31
    12. feral

      feral Well-Known Member

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      I saw that last night I'll wait for a dealer to pop up and give them a whirl
       
      feral, Feb 9, 2015
      #32
    13. Beaver

      Beaver Well-Known Member

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      WP_20150211_001.jpg Having read and seen all of this, I found myself modding some of my slightly damaged 120sr blades to experiment with the "tapered blade tips" as on the Cyclone blades. They definitely do deflect air outward and away from the ends of the blades. I can't say for certain there was any benefit in this case, the tips of this set of blades were chipped and I had to remove approximately 12mm to get them at equal length and remove previous damage, so the head-speed has increased. The heli does lift much faster when throttle is punched, and seems more stable than before, but probably due to head-speed. I can say however that there was less blade noise than before compared to stock blades. Just for fun, I shot some video of the test run. (Here's 2 minutes you'll never get back!) :p
       
      Last edited: Feb 12, 2015
      Beaver, Feb 12, 2015
      #33
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