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Cabin hop reducer.

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  • Cabin hop reducer.

    After installing my Gyro-Tech carbon fiber blades all of the vibrations were gone with the exception of a little 2/rev or cabin hop .

    I had motorcycle shimmy dampers on the control rods mounted at the scissors the control rods are connected to,that

    really helped a lot with the other blades,since then they have been removed. I still had just a slight amount of 2/rev , I

    believe that's minimal because of the blades stiffness and the urethane bushing in the mast,The shake has been reduced

    to almost nothing by the addition of one shimmy damper to the upper mast its self. The damper has 25 different settings

    I have set the damper to about 75% .So between the urethane bushing and the damper I am vibration free Will send a picture as

    soon as I go to the hanger.I now can drink my coffee when flying and not see vibration rings in it.I fly hands off for 5 minutes at a time,

    .My trim system is the best ever,its the stabilator attached to the rotor head its self

    Last edited by eddie; 02-21-2018, 01:34 PM.
    Best Regards,
    Eddie Sigman,Polvadera,nm
    (575) 835-4921

  • #2
    Pictures and video of your setup and stick shake would be appreciated, we have a set of GT blades on their way for an ELA so we have an interest in your progress.

    Comment


    • #3
      Wow, great job!!!
      Resistance is futile…… You will be compiled!
      Cheers,
      John Rountree

      PRA- Director, Secretary
      PRA- Business Manager

      PRA31 - Vice President of S.D. Rotorcraft Club
      http://www.Pra31.org

      U.S. Agent for Aviomania Aircraft... the most stable gyroplane on the market today.
      See: Aviomania USA http://www.AviomaniaUSA.com

      OEM Dealer for MGL Avionics - glass cockpit EFIS for Experimental aircraft Ask about DISCOUNTS for PRA MEMBERS

      Comment


      • #4
        these are the pictures of the install. Alan I really do like the Gyro-Tech blades,they are smooth and being stiffer they seem to fly more responsive than the other

        blades I have had.
        Best Regards,
        Eddie Sigman,Polvadera,nm
        (575) 835-4921

        Comment


        • #5
          I see the shimmy damper but I still can't tell what is hooked on to and exactly how. Any better angles

          Comment


          • #6
            I cannot understand how it works either.
            Resistance is futile…… You will be compiled!
            Cheers,
            John Rountree

            PRA- Director, Secretary
            PRA- Business Manager

            PRA31 - Vice President of S.D. Rotorcraft Club
            http://www.Pra31.org

            U.S. Agent for Aviomania Aircraft... the most stable gyroplane on the market today.
            See: Aviomania USA http://www.AviomaniaUSA.com

            OEM Dealer for MGL Avionics - glass cockpit EFIS for Experimental aircraft Ask about DISCOUNTS for PRA MEMBERS

            Comment


            • #7
              The bottom part of the mast is solid ,the bracket extending to the rear is attached to the bottom mast,the damper is attached to the bracket

              the front part of the damper is attached to the front of the upper mast that does move by a rod that extends from the body of the damper forward.

              the big bolt on the side of the mast that is where the urethane bushing is located inside the mast that doesn't move. picture #3 shows the rod

              end attached to the upper mast that moves fore and aft.
              Last edited by eddie; 02-20-2018, 08:01 PM.
              Best Regards,
              Eddie Sigman,Polvadera,nm
              (575) 835-4921

              Comment


              • #8
                the drawings are crude but should help understand how it works.
                Best Regards,
                Eddie Sigman,Polvadera,nm
                (575) 835-4921

                Comment


                • #9
                  I have been concerned about the small amount of vibration that was left after going to the Gyro Tech blades,

                  I have assumed that the blades left Poland completely balanced and tracked so I considered that even though

                  being the great superior master mechanic that I am I probably screwed something up when I assembled it.

                  So I went back to the basic's and actually read the assembly manuel this time,even though I had spent a lot of time

                  getting the stringing process right the first time,I started there and checked the stringing with the blades mounted to

                  my Gyro,and lo and behold it was off by about an 1/8" I loosened up one side and beat on it with a 5 lb sledge hammer

                  until it was back in place (JUST KIDDING) I got it back in position and retorqued the bolts,then I went and recentered the

                  cordwise adjustment which I had about 0.006" off to one side. I had left the tracking alone as I never touched that.

                  When I prerotated it before there was a certain RPM that the blades briefly vibrated just a little I noticed that it was gone,

                  after getting air under my wheels I was surprised that the little cabin shake was gone and the slight fore/aft stick vibration

                  was almost completely gone. Go figure. I quess the point is don't ever take anything for granted.check it twice and then once more

                  after installation.
                  Best Regards,
                  Eddie Sigman,Polvadera,nm
                  (575) 835-4921

                  Comment


                  • #10
                    You raised my eyebrows with the 5 lb sledge bit. Good job! When I wrote with GT Poland a while back they said they only balance the blades but do not track. That was up to the customer. But I guess its a testament to their quality if they performed so well right out of the box for this long. BTW I didn't get a manual with mine, only the Guarantee sheet and packing list. Tried to DL it but the link on their site is inoperative. Is there a PDF handy?

                    Comment


                    • #11
                      Actually Brian there is a video of the tracking process used by them,and they also use the PB-4 machine that Mike Goodrich trained them on.

                      they have a rotor head mounted on a pylon out side and spin the blades up with a electrical motor and track them that way.

                      I don't of any files for the blades my manuel was just a couple of pages,the info was the generic info about stringing and tracking.

                      Every good tool box should have a big hammer in it,when everything else fails just beat on it until it works.





























                      Best Regards,
                      Eddie Sigman,Polvadera,nm
                      (575) 835-4921

                      Comment


                      • #12
                        I have been concerned about the small amount of vibration that was left after going to the Gyro Tech blades,

                        I have assumed that the blades left Poland completely balanced and tracked
                        Funny, you'd wondered the same thing about your Sport Rotors . . .

                        so I considered that even though being the great superior master mechanic that I am I probably screwed something up when I assembled it.
                        . . . although you never questioned your own installation back then.

                        Nice to hear that you're finally reading the manual, and not reflexively blaming the blade mfg. for something you did.


                        PP - ASEL complex (Piper 180, C206, RV-7A), SP - Gyro (Calidus, RAF, SC2), soloed in gliders; checkride soon

                        Wasn't happy with my RAF's pitch instability, so I installed a Boyer H-Stab to my great satisfaction!

                        "
                        When an honest but mistaken man learns of his error, he either ceases to be mistaken -- or he ceases to be honest."

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