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  • How do I.... Roll

    Guys,

    Today I spent from 10am till 6pm at the site flying trying out stuff
    in between teaching planes. Had 8-10 good flights.

    Now I can Loop and do a pirot in forward flight and then contiune in
    the direction I was going. Double stall turns as well.

    Now I tryed a Roll....

    Got stuck 100-150 ft away inverted lucky I had height plus my raptor
    hovers inverted as I discovered! I got it back after a debate with my
    airlons.

    But How do I roll I put full left in and lowered the collective but she got
    stuck in the middle of the roll.

    I can also land side on to me stood in pilots box facing forwards as it lands
    side on to me, and nose in on almost hover.... Got drifting nailed
    left/right/forwards/backwards.. er backwards at speed as well :-)


    Ade: Those tips on turns on how to do it has it sorted out totally I just
    everynow and then still use rudder and slide it on by ;-)


    So How the heck do you roll a Heli....
    Mark
    www.uavaerialservices.co.uk
    BNUCs - Operations certified
    CAA - Permit for Aerial Work

  • #2
    Hey Disc,

    The trick to rolling a heli in essence is not to use too much pitch, as this will slow the forward speed too much. The timing of when the pitch is changed is also pretty critical, otherwise the model will slide sideways as well as possibly climb or descend.

    For the first few rolls try leaving the pitch where it is for normal forward flight, as you dont actually need to change the pitch at all, okay, you will end up with a barrel roll instead of a nice smooth roll. To move from that to a nice smooth roll is just a question of getting the pitch amout and timing right.

    If you imagine the model flying along in upright forward flight, as you add that left aileron to start the roll, slowly decrease the pitch, as the model becomes knife edge, you need to be at 0 degrees pitch (Centre stick), then as the model rolls from knife edge to inverted, start feeding in the negaitve pitch until you have enough so the model doesn't descend when it is inverted. Then once the model is rolling from inverted back to knife edge the other side, increase the pitch from negative through 0 degrees at knife edge back to positive when the model has reached right way up again.

    Having found that the model will hover inverted, hopefully you will have found the negative pitch stick position, so when you roll from knife edge to inverted in future you will know at what point the stick needs to be to sustain the inverted part of the roll.

    This is one of those things that although isnt particularly difficult, it does take a few tanks to get the timing right of the necessary inputs.

    Good luck!

    Cheers,
    Pete.
    Crashed and burned, or just got your fingers burnt???
    Rise from the ashes with
    Phoenix Model Aviation Ltd - For Flight training, Model setups & test flights and general advice just south of Bristol.

    Comment


    • #3
      Okay got that....

      Found inverted hover when it counts...

      I May try it saturday afternoon, I'll let you know what happens!!


      Barrel Rolls are good enough for me!
      Mark
      www.uavaerialservices.co.uk
      BNUCs - Operations certified
      CAA - Permit for Aerial Work

      Comment


      • #4
        Okay done the barrel roll at Height.... What a big roll not good
        but my 1st one is done.
        Mark
        www.uavaerialservices.co.uk
        BNUCs - Operations certified
        CAA - Permit for Aerial Work

        Comment


        • #5
          Well done my friend!

          Now you have the barrel roll, which as you say, isn't particularly pretty, but at least it's British!

          The next step is to start adding some pitch control to smooth it out to a nice smooth roll which doesn't gain or loose any altitude. This is achieved by following these basic steps;

          First add some left or right aileron to initiate the roll, then at the same time, start changing the pitch in time with the speed the model is rolling, you need to aim for being at 0 degrees (Centre stick) when the model reaches knife edge and be at the inverted hovering point by the time the model becomes inverted. Then do the same in reverse, so this time starting at negative pitch, as the model rolls back through knife edge the other side, the pitch needs once again to be at 0 degrees (Centre stick), increasing it back to positive pitch as the model rolls upright on the last part of the roll.

          It might not be a bad idea to pause half way through for a second or two with the model inverted, providing you have enough negative pitch to sustain it, the model will happily fly along inverted, which gives you a second or two to gather yourself and prepare for the second part of the roll. Once you move that aileron stick you are committed, whereas when the model is either upright or inverted you can pause for a few seconds if you feel you need to.

          Like most manoeuvres it can be broken down into small parts, so you could if you wished fly off away from you left to right or right to left, turn and fly back across yourself, do a half roll to inverted, then pause then another half roll back to right way up. It is easier to do it this way than to have a go at the whole thing in one go.

          Good luck!

          Cheers,
          Pete.
          Crashed and burned, or just got your fingers burnt???
          Rise from the ashes with
          Phoenix Model Aviation Ltd - For Flight training, Model setups & test flights and general advice just south of Bristol.

          Comment


          • #6
            sorry for the slow reply, went to a party on friday night and its taken me this long to recover.... it never used to be this hard!

            There are 2 vitally important parts to the Roll.

            First is collective timing, second is nose up/down attitude.

            The best thing to do is break the roll down to 4 points, Right way up, 2 knife edges and inverted.

            Through knife edge you need to be seeing zero pitch and the pitch in inverted should be the same amount of pitch as you started the roll with. It should be a smooth transition as the model rolls. Getting the timing wrong is what gives the barrelley effect.

            Most people come off the positive too early, making the model fall slightly, then dont put enough negative pitch in through the inverted section making it fall slightly more. (hope your doing it high!) then snatch the positive pitch back in too early after the second knife edge making the model shoot sideways as it exits the roll.

            The attitude of the model through the roll will affect the forward speed. Most models will try to raise the nose causing the model to slow down. If your a fixed wing pilot you may be putting down elevator through the roll too making it even worse! Feeding a small amount of up elevator through the inverted section will fix this.

            to start with do the roll at 45degs to yourself this will help you see exactly what the model is doing through the roll in all respects. Once you have the hang of it, try to centre the model infront of you. So the model is travelling down the flight line with the inverted section directly infront of you. That will please the pattern fliers out there.

            hope this helps.

            Ade
            www.accurc.com
            adrian@accurc.com
            This is an apple free zone
            anybody can be an Arsehole, it takes real commitment, dedication and a whole lot of effort to be nice.

            Comment


            • #7
              Guys,

              Thanks for all the Advice I'll try it out and

              Ade er recovering from partys takes longer as we get older ;-/
              Mark
              www.uavaerialservices.co.uk
              BNUCs - Operations certified
              CAA - Permit for Aerial Work

              Comment


              • #8
                I found that doing consecutive rolls helps a lot with the pitch timing, however you must be quick to abort the next roll if your previous roll when a bit pear shaped. Stationary rolls can help as well

                Don't forget to practice rolling in both directions (must remember that myself !)
                Janek

                Why does it always persist down at weekends ?

                Comment


                • #9
                  janek you didnt actually get out the hover did you? :-)

                  Ade
                  www.accurc.com
                  adrian@accurc.com
                  This is an apple free zone
                  anybody can be an Arsehole, it takes real commitment, dedication and a whole lot of effort to be nice.

                  Comment


                  • #10
                    Yea, but not very often though
                    Janek

                    Why does it always persist down at weekends ?

                    Comment

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