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  • #16
    Originally posted by Gyro28866 View Post
    I don't think so!!! The teeter limits are positioned horizontal while in flight. The centripetal forces from rotation do this. The only time they are hanging/drooping down is in low RRPM, to limit the amount of teeter. The only time I notice them is from about 60 to 80 RRPM, while slowing to stop the rotors rotation. It is pretty unnerving for me, when they are engaging. There is a pronounced side to side motion and corresponding stick pressure. To assist in slowing the rotor, upon landing and stopping, I turn the Dominator so the incoming wind is 90* to the machine on the advancing blade side. In higher velocity winds, I will actually turn 180* and let the incoming air feed from behind. These two maneuvers reduce the amount of flapping because of the reduction the relative wind velocities to the AOI and AOA of the rotor and blades.
    The teeter stops on The Predator donít move and limit teeter movement to 18 degrees total.

    It appears to me the teeter stops on G Rís head donít move either.

    I do not have a strategy for slowing the blades other than putting on the rotor brake below 100 rotor rpm. I work to keep the rotor tilt even left to right to avoid low speed blade divergence and excess control input pressure.
    Regards, Vance Breese Gyroplane CFI http://www.breeseaircraft.com/

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    • #17
      Since I apparently have a modified Air Command Rotor Head, Can someone tell me if a regular AC rotorhead has separate STOPs pieces on it, or does the design of the head naturally stop the blades at the proper degreed angle?
      Likewise for the Dragon Wings- does the dragon wing head have built in stops or is the simple construction of the head enough to limit it?
      Thanks for any help.
      Geoff
      Air Command CLT Tandem
      BROKE, SIEZED, NO GOOD, Subaru 2.2 FI- Stock
      68" Warp Drive
      28' Dragon Wings
      0 #'s Thrust

      Comment


      • #18
        Originally posted by N447MR View Post
        Since I apparently have a modified Air Command Rotor Head, Can someone tell me if a regular AC rotorhead has separate STOPs pieces on it, or does the design of the head naturally stop the blades at the proper degreed angle?
        Likewise for the Dragon Wings- does the dragon wing head have built in stops or is the simple construction of the head enough to limit it?
        Thanks for any help.
        Geoff
        Both heads in stock condition only have aluminum stop plates like the head you have.
        Your towers are too long.
        As quoted before, you need a stock dual bearing rotor head from RFD or Air command.
        Air Command is back in business and is your best bet for the product you need.
        Call RFD, he may have a head to sell you also.
        Last edited by gyrojake; 05-25-2018, 03:49 PM.
        Life,The leading cause of Death

        Live and Learn--OR--Die and be an example

        321.252.7705

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        • #19
          Originally posted by Vance View Post

          The teeter stops on The Predator donít move and limit teeter movement to 18 degrees total.

          It appears to me the teeter stops on G Rís head donít move either.

          I do not have a strategy for slowing the blades other than putting on the rotor brake below 100 rotor rpm. I work to keep the rotor tilt even left to right to avoid low speed blade divergence and excess control input pressure.
          The teeter stops Dave uses are designed for parking or to taxi without the blades spinning.
          They are bolted to the top of the towers and stop the blades from flapping in the wind, they are disengaged by the centrifugal force delivered by rotation for normal flight.
          Life,The leading cause of Death

          Live and Learn--OR--Die and be an example

          321.252.7705

          Comment


          • #20
            Originally posted by N447MR View Post
            Likewise for the Dragon Wings- does the dragon wing head have built in stops or is the simple construction of the head enough to limit it?
            RFD rotorhead for bigger rotors (two main bearings) has centrifugal teeter stops but me personally remove them since I found that they make taxiing with slow rotating rotor too uncomfortable though such teeter stops are very useful for, say, heavy 30' SportRotors. In my personal experience teeter stop plate below a hubbar is quite enough a DW rotors.

            Alex Lameko
            Russian gyroforum
            Visit my collection of gyro videos

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            • #21
              Originally posted by gyrojake View Post

              The teeter stops Dave uses are designed for parking or to taxi without the blades spinning.
              They are bolted to the top of the towers and stop the blades from flapping in the wind, they are disengaged by the centrifugal force delivered by rotation for normal flight.
              I've seen those on the sportcoper setup in our hangar, I was wondering if there was a "teeter stop" on the bottom side. Something for the blades to hit that wasn't aluminum as it looked like maybe there was something attached to mine at some point.

              Okay- So I finally got back to the airport yesterday and to my surprise, the teeter block was NOT in the top hole. This really surprised me because I thought that it had been there all along and so hadn't considered it further. Always humbling. None of the guys at the hangar thought of it in all this time either. I'm very grateful to have the additional online forum help, thank you.

              With the block now in the top hole, the teeter is as it should be. So it seems the towers were made appropriately, although it is clear the blades aren't tracking so on to learning how to do that to dragon wings.

              I didn't get a lot of time to play with it after that, but it seemed to handle a little "tighter" as well. Looking forward to playing some more.

              I'll have to contemplate the dual vs. single bearing head debate (which I've read extensively so far)
              Ernie got back to me and said he could make me a dual bearing head for $1500. I haven't talked to AirCommand about it.

              Air Command CLT Tandem
              BROKE, SIEZED, NO GOOD, Subaru 2.2 FI- Stock
              68" Warp Drive
              28' Dragon Wings
              0 #'s Thrust

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              • #22
                I don't see where the double bearing rotor head is of any benefit,I have a single bearing head on my RAF with no problems.
                Best Regards,
                Eddie Sigman,Polvadera,nm
                (575) 835-4921

                Comment


                • #23
                  Originally posted by eddie View Post
                  I don't see where the double bearing rotor head is of any benefit,I have a single bearing head on my RAF with no problems.
                  Eddi,
                  It is because of the oscillations of the radial load, the axial load is no problem but with big heavy loads the radial load is compensated with the dual bearing stack.
                  These bearings are designed for axial thrust loads. Better safe than sorry, I know your worth another couple -o-bucks for safety redundancy.
                  Life,The leading cause of Death

                  Live and Learn--OR--Die and be an example

                  321.252.7705

                  Comment


                  • #24
                    Originally posted by gyrojake View Post

                    Eddi,
                    It is because of the oscillations of the radial load, the axial load is no problem but with big heavy loads the radial load is compensated with the dual bearing stack.
                    These bearings are designed for axial thrust loads. Better safe than sorry, I know your worth another couple -o-bucks for safety redundancy.
                    In all the reading though, just one accident involving suspect rotor head bearings on a J2 that was stored outside and displayed significant issues/warnings that should have been addressed before it failed.
                    Air Command CLT Tandem
                    BROKE, SIEZED, NO GOOD, Subaru 2.2 FI- Stock
                    68" Warp Drive
                    28' Dragon Wings
                    0 #'s Thrust

                    Comment


                    • #25

                      With the block now in the top hole, the teeter is as it should be. So it seems the towers were made appropriately, although it is clear the blades aren't tracking so on to learning how to do that to dragon wings.
                      I will attempt to explain this in a manner for you to also visualize.
                      On the Dragonwings, the only adjustment for the end user is just to adjust for lead/lag. Place the rotor onto 2 saw horses, several feet from where the blade attaches to the hubbar. One sawhorse for each blade. you will adjust the sawhorses closer or farther out, attempting to get the hubbar into a slightly lower position than the rotor blade tips. You will attach a string and pulled tight to the tip of each blade, I use the seam where the upper skin is attached. This position is exactly the same on each blade. With the string pulled tightly across, the hubbar teeter block should be slightly below the string. roughly 1/4" to 1/2". If the teeter block is touching the string, then adjust each of the two sawhorses out the same amount, until the string is not touching. The string should be crossing the teeter block at the dead center mark.
                      Also, because Ernies blades have a length wise twist. You have to compensate for that also. Cut you 2 pieces of automotive fuel line about two inches long each. These pieces will be inserted between the saw horse and the rotor blade. They MUST be inserted parallel the blades cordline, approx. 1 3/4" from the leading edge. this will get the blades into a position which closely resembles flying attitude. loosen the grip of the 6 blade bolts, on each blade strap. and adjust the lead/lag until you get it right.
                      This all sounds complicated, but it really is not. real easy, once you have done it.
                      Meet me at Mentone, and I will be glade to show you.
                      David McCutchen
                      615-390-2228
                      Bensen B7m, 90 hp Mac
                      Dominator Tandem, 100 hp Hirth
                      Kolb Mark III Classic, 80 hp Verner
                      Certified - Advanced Master Beef Producer
                      EAA Member #0511805
                      PRA Member #28866
                      PRA Chapter 16 Member
                      Secretary & Treasure - PRA Chapter 16
                      President / Sylvia - Yellow Creek Volunteer Fire Dept.
                      Chairmen - Dickson County Veteran's Day Committee
                      Volunteer - Dickson County Airport Aviation Day Committee
                      2 busy 2 No!

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                      • #26
                        Another way to adjust the lead/lag is to slightly loosen the bolts on the blades and then run up the blades to a speed where the blades are carrying

                        a load and then slow down and let the blade stop without the brake or any assistance,after they have stopped tighten the bolts,taxi back to the hanger

                        and torque the bolts down. the blades adjusted this way will find its own lead/lag.

                        Jake with the blades teetering where does the radial load come from ?
                        Best Regards,
                        Eddie Sigman,Polvadera,nm
                        (575) 835-4921

                        Comment


                        • #27
                          Originally posted by eddie View Post

                          Jake with the blades teetering where does the radial load come from ?
                          When your rotor is spinning under load, the drag of the rotor loads and unloads radial forces on the bearing.
                          The teeter takes care of the dissymmetry of lift not radial loads.
                          My best analog would be to stand in the back of a pick up truck at 60 miles per hour.
                          Hold a piece of 2'x2' plywood edgewise in the wind then the flat surface in the wind at 300 times a minute and you will then notice the radial oscillations your mast and bearings are withstanding.
                          I'm sure C.B. can explain it better.
                          The more support you give to the length of the bearing surface the more you displace the radial load and consequently displace the axial load with dual bearings, which means your bearings are taking less of a beating.
                          Anything over 750lbs in my opinion should have 2 bearings.
                          Last edited by gyrojake; 05-27-2018, 03:10 AM.
                          Life,The leading cause of Death

                          Live and Learn--OR--Die and be an example

                          321.252.7705

                          Comment


                          • #28
                            Jake thanks for the explanation,easy to understand.
                            Best Regards,
                            Eddie Sigman,Polvadera,nm
                            (575) 835-4921

                            Comment


                            • #29
                              Originally posted by gyrojake View Post

                              When your rotor is spinning under load, the drag of the rotor loads and unloads radial forces on the bearing.
                              The teeter takes care of the dissymmetry of lift not radial loads.
                              My best analog would be to stand in the back of a pick up truck at 60 miles per hour.
                              Hold a piece of 2'x2' plywood edgewise in the wind then the flat surface in the wind at 300 times a minute and you will then notice the radial oscillations your mast and bearings are withstanding.
                              I'm sure C.B. can explain it better.
                              The more support you give to the length of the bearing surface the more you displace the radial load and consequently displace the axial load with dual bearings, which means your bearings are taking less of a beating.
                              Anything over 750lbs in my opinion should have 2 bearings.
                              So is that kind of like a shear force on the bearings?
                              also, is that 750#s all up or empty machine?
                              thanks for the patience in exposing and teaching.
                              Geoff
                              Air Command CLT Tandem
                              BROKE, SIEZED, NO GOOD, Subaru 2.2 FI- Stock
                              68" Warp Drive
                              28' Dragon Wings
                              0 #'s Thrust

                              Comment


                              • #30
                                Originally posted by N447MR View Post

                                So is that kind of like a shear force on the bearings?
                                also, is that 750#s all up or empty machine?
                                thanks for the patience in exposing and teaching.
                                Geoff
                                Wet and passengers.
                                Here look at this.
                                Remember, axial is thrust and radial is a bending moment 90* of the thrust.
                                Life,The leading cause of Death

                                Live and Learn--OR--Die and be an example

                                321.252.7705

                                Comment

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