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  • #16
    E. Paul aka KolibriI

    I started this thread to share some knowledge and concerns I have about spherical rod ends and preflight inspections with people who might be interested.

    In my experience there are some people who I can't teach and I am not interested in continuing to try.

    I am not responsible for what you imagine I wrote in my posts and I have no desire to play whatever game you are playing.

    I don't see a reason to answer your questions that I feel have already been answered in this thread.

    I am not concerned that you feel my answers are not definitive enough for your purposes.

    I do not agree with your assessment of Eddie.

    I feel he is a smart capable man who understands things on a high level.

    Eddie has earned my respect and I feel he is a friend.
    Regards, Vance Breese Gyroplane CFI http://www.breeseaircraft.com/

    Comment


    • #17
      Thank you Vance.

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

      Comment


      • #18
        Vance, for the past three years I have been trying to educate RAF owners about their inferior OEM control rod ends.
        It is certainly no "
        game" to me.

        Your advice about checking for binding rod ends is good. I quoted it in 2015.

        However, your recent posts clearly imply that rod ends break only because they're bent, and they're bent only because of exceeding their misalignment angle.
        I've tried to point out that that such is not always the case, especially with OEM RAF parts.
        They will break without having been grossly misaligned. This has been recognized by RAF owners since 2004:


        The lack of quality was verified by the metalurgical lab in Salt Lake City that Jim Mayfield sent one of his cracked bearings to. It cracked when an attempt was made to loosen the lock-nut from the threaded shaft with a wrench. That was scary.
        KenSandyEggo 04-27-2004, 07:05 AM
        Rotary Wing Forum > Kit Makers & Manufacturers > RAF - Rotary Air Force > 50 hour evalution of the RAF
        A few years ago, Jim Mayfield had an RAF supplied rod-end bearing crack in his control system as the nut was being loosened with a wrench. He sent them to a metalurgical lab in Salt lake City, where it was confirmed that they were full of impurities and of extremely low quality. I heard pretty much the same thing from a tech at a bearing distributor when I took a cracked one in for replacements. He said he could see the impurities in the broken stem with his naked eye. He also said he could get these for about $1.50 or so, but he couldn't morally do that to his customers. His words......."This is junk."
        KenSandyEggo 06-19-2004, 06:29 PM
        Rotary Wing Forum > Kit Makers & Manufacturers > RAF - Rotary Air Force > RAF views
        Paul, it's not just a matter of bending them to see if they are "good." There are a lot of vibrational forces going on and they don't break only from twisting or bending. I've had 2 break without any force whatsover being applied by me. When a metalurgical lab and a bearing house tech says they're "crap" and full of impurities, that's good enough for me not to bet my life on to save a few bucks.
        KenSandyEggo 06-21-2004, 04:50 PM
        Rotary Wing Forum > Kit Makers & Manufacturers > RAF - Rotary Air Force > RAF views
        From the Aurora catalog:
        "Axial static load capacity is the force that is applied through the bore of the ball.
        For Aurora two-piece rod ends, maximum axial static load capacity is recommended to be 15 percent of the ultimate radial static load capa
        city."

        Thus, your "more than up to the task" .250 RAF OEM rod end (which failed in G-BWAE) has an axial static load capacity of just 142.8 lbs.
        As Doug Riley posted in this thread:


        In my opinion, 1/4" shank rod ends simply lack the strength for real-world gyro operations, despite their rated strength (which can only be achieved in an abuse-free environment, not when slamming about on grass or occasionally flapping blades).
        The Jim Mayfield mod of 5/16" pitch control rod ends which I installed uses the Aurora XAM-4T of 8,452 lbs. max radial static load,
        and 1,267.8 lbs. axial static load capacity, i.e., nearly 9x the strength of the RAF OEM 1/4" you have stubbornly reported as acceptable.
        This is an easy and inexpensive mod, and greatly enhances RAF safety.


        ______
        In my opinion, any RAF owner active on this forum must have by now become at least vaguely aware of OEM $2 Chinese control rod end issues.
        Their preemptive replacement before failure -- regardless of apparent condition -- has been universally urged by everyone from Ken Janulewicz to
        Ron Awad to Brandon "route66" to Jim Mayfield to the British CAA.

        Not even RAFSA uses them anymore (having gone to the perfectly acceptable Alinadal PM-6-G).
        It's only you who defends these junk parts:


        If I owned an RAF gyroplane I would replace the spherical rod ends because I like quality parts in my control system; not because they are not up to the job.

        If I were to pre-flight an RAF and found the control rods clean, showing signs of maintenance and not binding I would not ground the aircraft because I was not familiar with the rod end manufacture.
        Waffling. Just waffling.
        The discussion here should beabout what most enhances aviation safety, and sets the best example for gyro pilots.
        You have not explicitly admonished RAF owners to ditch their OEM control rod ends. (Everyone else has.)
        You haven't even recommended that owners at least remove them for a careful inspection.

        The FAA's ADM program lists five major hazardous pilot attitudes, and those RAF owners who stubbornly resist good advice
        about replacing their junk control rod ends exhibit two of the five:
        Anti-Authority ("Don't tell me what to do! ")
        Invulnerability ("It won't happen to me! ")


        In my opinion, Vance, your consistent "I prefer quality control rod ends, but the original RAF parts are 'more than up to the task' if well-maintained and not binding up"
        is very poor advice to those owners exhibiting an "Invulnerability" attitude.

        You declare eddie to be a "
        friend" yet you still continue to justify his old parts while praising his intelligence along the way.

        I believe that a CFI should always champion the highest quality in parts and maintenance, and not offer, as you have, such dangerous equivocation.



        ______
        The middle two pair of 3/8" rod ends at the RAF scissors have very little angle swiveling, thus the 6 Heim HM-6M are fine there. However, I've been rethinking a bit the upper and lower pair which are attached to very dynamic arms with a greater range of motion. Although the 6 Heim HM-6M will suffice there, there's little extra margin of misalignment, so one's washered adjustment must be spot on. Perhaps rod ends with greater misalignment are a better choice, such as the Aurora AM-6T (12) or the CM-6ET stainless steel (17-4 PH - AMS 5342) with 22.

        (In Aurora's nomenclature, the T-suffix denotes a self-lubricating PTFE liner. This is probably a prudent choice for those lower rod ends so near runway splash.)

        Either of these Auroras is >2x as strong as the very good Heim HM-6M, and with >3x the misalignment angle. (The Aurora HXAM-6T is 3x as strong.)
        I think I'll replace my lower pair of Heim HM-6Ms with one of these three alternatives.

        While I'm at it, I will replace most of the other OEM Chinese RAF rod ends found throughout my gyro, especially the landing gear and engine mounts.
        Heim HM-6Ms seem a good balance between strength/quality and price, and they're immediately available from Spruce.

        In summary, I strongly urge all RAF owners with OEM control rod ends to take this issue seriously. Those with allegedly little time or money should at least remove/inspect/replace the lower three rod ends (two 3/8" and the outside 1/4"), as these seem to be the most vulnerable to weather and abuse, and are the most difficult to adequately pre-flight. Total parts cost will be <$100, and work will take about 90 minutes.

        If your life isn't worth that, then at least please fly solo and don't risk a passenger with your stubborn apathy and sloth.

        Safe flying, Kolibri
        PP - ASEL (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."

        Comment


        • #19
          In my opinion my posts don't "clearly imply" that there is only one reason spherical rod ends break.

          That is something E. Paul made up and I chose not to respond to because it is nonsense.

          In this thread I am describing one way to break a spherical rod end.

          It is my observation that when a spherical rod end breaks from poor quality or overloads the failure is usually in the area of the ball.

          It is my observation that when a spherical rod end breaks in the area of the threads it is usually from misalignment.

          A spherical rod end may also break at the threads from the jam nut being over torqued.

          In my opinion if a control rod; even with aircraft quality spherical rod ends will not rotate slightly though out the throw; in service the spherical rod ends will be misaligned enough to break.

          Regards, Vance Breese Gyroplane CFI http://www.breeseaircraft.com/

          Comment


          • #20
            Originally posted by Kolibri View Post


            While I'm at it, I will replace most of the other OEM Chinese RAF rod ends found throughout my gyro, especially the landing gear and engine mounts.
            I don't mean to add fuel to a heated subject, but for all the ranting about inferior OEM parts, why are so many of them still on the ship? No disrespect intended, I'm simply curious.

            Comment


            • #21
              Brian Its because Kolibri's RAF was a corroded out rust bucket when he bought it, he got screwed his rodends were so corroded he had to replaced them

              and just about everything else because of corrosion. And now for some reason he thinks he is the RAF safety Guru. My RAF is in very good condition as are the

              other ones I have seen ..There is really nothing to his rants that support that we are gong to die because we don't listen to him.

              he is the know-it-all about the RAF and now all Gyros in general,


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

              Comment


              • #22
                I don't mean to add fuel to a heated subject, but for all the ranting about inferior OEM parts, why are so many of them still on the ship? No disrespect intended, I'm simply curious.
                None taken, Brian, and it's a fair question.
                Regarding my RAF's rod ends (none of which were "
                so corroded"), I at once replaced what were imperative back in 2015: the control system rod ends.
                I next replaced what was highly prudent: the alternator mounts (adding a long single bolt).
                Finally, I will, as earlier described, replace what I've concluded are generically prudent (though not mentioned by other owners).
                Few RAF owners have done the first two steps, and none that I know of the last step.


                And, btw, eddie has never seen my RAF, else he'd know that it was never a "corroded out rust bucket".
                I wouldn't have purchased any gyro in such condition. It was shiny and rust-free. It's even better now, because I've cared to make it so.



                ________
                There is really nothing to his rants that support that we are gong to die because we don't listen to him.
                eddie, my sincere offer that I posted to buy you a set of Heims for your RAF is rescinded. (I now recall the excellent advice of Matthew 7:6.)
                Well, I hope that you don't auger in, but if you do at least the investigators will have a good preliminary theory why.


                ________
                Vance, my forum name is Kolibri. It is proper Netiquette to use only to that.
                This is what I practice, and if a Member uses the lowercase for his name (such as dunc or eddie), that's what I use.
                My personal info is not available to non-Member lurkers, yet you post it nonetheless. I believe this is explicitly forbidden by Forum rules.
                Please cease and desist. Thank you.



                . . . I am describing one way to break . . .
                . . . is usually from . . .
                Ah, now you're properly implying other possible causes. You weren't previously.


                It is my observation that when a spherical rod end breaks from poor quality or overloads the failure is usually in the area of the ball.
                It is my observation that when a spherical rod end breaks in the area of the threads it is usually from misalignment.
                Perhaps, but neither seem to be the general observation of many RAF owners regarding their old rod ends.
                They can and do break elsewhere and elsewhy, as I've quoted their posts from 2004.


                ______
                There are three levels of design/parts quality:


                1) top-notch, which have no record of failure, nor seem ever likely to fail

                2) mid-range (i.e., less than top-notch, but better than atrocious) which occasionally fails

                3) atrocious


                The atrocious rarely make it on even E-AB kits, because it fails so quickly and so often.

                The top-notch is also rarely seen, because of weight or expense or inconvenience or wait factor. An example of top-notch that comes to mind
                are the rod ends which Sport Copter uses in their gimbal arm: the Aurora HXAM-6T high misalignment (22) rod ends. (Theirs are specially made
                with 0.25" ball I.D., eliminating the need for a weaker ⅜" Orlite bushing.) With a body of heat treated 4340 steel, this is hell-for-stout at 11,781 lbs
                ultimate radial static load capacity. Self-lubricating with a PTFE liner. Instead of the industry-common 3/8 shank, it has a 7/16. (The push tubes are
                much thicker than industry norm, to reduce buckling.) Everything thing about the part is top-notch. Its failure is nearly inconceivable.

                However, what we generally see in E-AB is the mid-range quality design and parts. Such is often cheaper, lighter weight, and off-the-shelf.
                The spectrum is quite wide, from bordering atrocious to approaching top-notch. The worrisome thing about mid-range is that it usually works
                sufficiently well not to cause alarm. The odd failure or two is generally written off as a fluke, or pilot error.

                In my view, aviation design and parts should be seen as "guilty until proven innocent".
                That is, by the way, the mindset of pre-flight and annual inspections.
                One assumes that something must be loose, cracked, bent, broken, corroded, chafing, weak, plugged up, backwards, or missing.

                In my shooting courses I mention to students that if I notice something odd in the tactical world three times, I "log it in" as worthy of discussion.
                (An example would be a certain handgun firing off an ejected live round, or a particular odd feeding failure in an AR such as base-over-bolt
                with lacquered steel case imported ammo).


                Once is incidence.
                Twice is coincidence.
                Thrice is enemy action.

                There have certainly been enough RAF rod end failures by now to justify not only warning but outright preemptive replacement.
                I would classify the old RAF OEM rod ends (AISI 1112b <Grade 0) as within mid-range but nearly atrocious. Many people concur.
                They needn't be bent from excessive misalignment to crack; they can crack from normal tightening/loosening, from normal use, and from normal vibration.

                And, because of the nature of rod ends in general, they are subject to bending loads even within their range of misalignment.
                (axial load + eye height = bending load). Now, this bending load must be within limits, of course, but it still exists.

                Thus, there is no reasonable justification of those RAF rod ends.
                They are not "innocent until proven guilty" on a case-by-case basis.
                Rather, they are definitely suspect and untrustworthy.

                It is wrong to defend them by claiming that they "generally" work because that will provide sufficient rationale for the cheap and lazy owners not to replace them.
                This is a disservice to aviation safety, and conduct unbecoming.

                I've attached my 2015 pdf (recently revised) about RAF rod end choices.
                Those interested in upgraded their parts to aviation-quality are welcome to post or PM me with any questions.

                Safe flying, Kolibri
                Attached Files
                Last edited by Kolibri; 02-17-2018, 09:41 AM.
                PP - ASEL (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."

                Comment


                • #23
                  Kolibri... I owned an RAF and changed out its rodends, and also used a bolt on the alternator. Do you have the updated nosewheel part? Mine failed on take off with my dad onboard and the nosewheel collapsed and the nose of the cabin dropped to the grinding us to a halt. I was staring down at the runway holding backstick till the blades stopped. It could have been ugly, but ended up with the only scratch I ever put on a gyro , and I had it fixed and flying in 3 hours. I had procrastinated for a year with that new part ....not installing it like I should have. Several RAF's have been totalled from this one defective part.
                  Curved stairway builder


                  Enjoy life...consider eternity.


                  www.stansstairways.com

                  Comment


                  • #24
                    Originally posted by Kolibri View Post
                    None taken, Brian, and it's a fair question.
                    Regarding my RAF's rod ends (none of which were "
                    so corroded"), I at once replaced what were imperative back in 2015: the control system rod ends.
                    I next replaced what was highly prudent: the alternator mounts (adding a long single bolt).
                    Finally, I will, as earlier described, replace what I've concluded are generically prudent (though not mentioned by other owners).
                    Few RAF owners have done the first two steps, and none that I know of the last step.


                    And, btw, eddie has never seen my RAF, else he'd know that it was never a "corroded out rust bucket".
                    I wouldn't have purchased any gyro in such condition. It was shiny and rust-free. It's even better now, because I've cared to make it so.



                    ________

                    eddie, my sincere offer that I posted to buy you a set of Heims for your RAF is rescinded. (I now recall the excellent advice of Matthew 7:6.)
                    Well, I hope that you don't auger in, but if you do at least the investigators will have a good preliminary theory why.


                    ________
                    Vance, my forum name is Kolibri. It is proper Netiquette to use only to that.
                    This is what I practice, and if a Member uses the lowercase for his name (such as dunc or eddie), that's what I use.
                    My personal info is not available to non-Member lurkers, yet you post it nonetheless. I believe this is explicitly forbidden by Forum rules.
                    Please cease and desist. Thank you.



                    Ah, now you're properly implying other possible causes. You weren't previously.


                    Perhaps, but neither seem to be the general observation of many RAF owners regarding their old rod ends.
                    They can and do break elsewhere and elsewhy, as I've quoted their posts from 2004.


                    ______
                    There are three levels of design/parts quality:
                    1) top-notch, which have no record of failure, nor seem ever likely to fail

                    2) mid-range (i.e., less than top-notch, but better than atrocious) which occasionally fails

                    3) atrocious




                    The atrocious rarely make it on even E-AB kits, because it fails so quickly and so often.

                    The top-notch is also rarely seen, because of weight or expense or inconvenience or wait factor. An example of top-notch that comes to mind
                    are the rod ends which Sport Copter uses in their gimbal arm: the Aurora HXAM-6T high misalignment (22) rod ends. (Theirs are specially made
                    with 0.25" ball I.D., eliminating the need for a weaker ⅜" Orlite bushing.) With a body of heat treated 4340 steel, this is hell-for-stout at 11,781 lbs
                    ultimate radial static load capacity. Self-lubricating with a PTFE liner. Instead of the industry-common 3/8 shank, it has a 7/16. (The push tubes are
                    much thicker than industry norm, to reduce buckling.) Everything thing about the part is top-notch. Its failure is nearly inconceivable.

                    However, what we generally see in E-AB is the mid-range quality design and parts. Such is often cheaper, lighter weight, and off-the-shelf.
                    The spectrum is quite wide, from bordering atrocious to approaching top-notch. The worrisome thing about mid-range is that it usually works
                    sufficiently well not to cause alarm. The odd failure or two is generally written off as a fluke, or pilot error.

                    In my view, aviation design and parts should be seen as "guilty until proven innocent".
                    That is, by the way, the mindset of pre-flight and annual inspections.
                    One assumes that something must be loose, cracked, bent, broken, corroded, chafing, weak, plugged up, backwards, or missing.

                    In my shooting courses I mention to students that if I notice something odd in the tactical world three times, I "log it in" as worthy of discussion.
                    (An example would be a certain handgun firing off an ejected live round, or a particular odd feeding failure in an AR such as base-over-bolt
                    with lacquered steel case imported ammo).
                    Once is incidence.
                    Twice is coincidence.
                    Thrice is enemy action.



                    There have certainly been enough RAF rod end failures by now to justify not only warning but outright preemptive replacement.
                    I would classify the old RAF OEM rod ends (AISI 1112b <Grade 0) as within mid-range but nearly atrocious. Many people concur.
                    They needn't be bent from excessive misalignment to crack; they can crack from normal tightening/loosening, from normal use, and from normal vibration.

                    And, because of the nature of rod ends in general, they are subject to bending loads even within their range of misalignment.
                    (axial load + eye height = bending load). Now, this bending load must be within limits, of course, but it still exists.

                    Thus, there is no reasonable justification of those RAF rod ends.
                    They are not "innocent until proven guilty" on a case-by-case basis.
                    Rather, they are definitely suspect and untrustworthy.

                    It is wrong to defend them by claiming that they "generally" work because that will provide sufficient rationale for the cheap and lazy owners not to replace them.
                    This is a disservice to aviation safety, and conduct unbecoming.

                    I've attached my 2015 pdf (recently revised) about RAF rod end choices.
                    Those interested in upgraded their parts to aviation-quality are welcome to post or PM me with any questions.

                    Safe flying, Kolibri
                    This is a simple thread with a simple point.

                    Don't put spherical rod ends in bending by adjusting them to where they exceed their maximum misalignment and a simple procedure for checking them during pre-flight.

                    I often see spherical rod ends in bending and it is easy to check in pre-flight.

                    I recently broke a quality spherical rod end by exceeding the maximum misalignment.

                    The thread is about all gyroplanes with spherical rod ends.

                    Kolibri went off on one of his toxic RAF rants misinterpreting information and condemning me for things he imagined I implied.

                    It is my observation people like to blame somebody else for their mistakes.

                    I find I learn more by recognizing my part in things that don't work out.

                    From my perspective Kolibri is operating on an emotional level. I find his posts reminiscent of religious histrionics.

                    I have never cared for screen names and prefer to address people by their given names. I am sorry if that violates some code on conduct I was not aware of and do not subscribe to.
                    Regards, Vance Breese Gyroplane CFI http://www.breeseaircraft.com/

                    Comment


                    • #25
                      "If you have an RAF with the original low-grade control rod ends, you'd be very wise to replace them with better parts."

                      Vance, you still haven't said this, and apparently cannot.
                      Noted. I'll move on.



                      ________
                      Kolibri... I owned an RAF and changed out its rodends, and also used a bolt on the alternator. Do you have the updated nosewheel part? Mine failed on take off with my dad onboard and the nosewheel collapsed and the nose of the cabin dropped to the grinding us to a halt. I was staring down at the runway holding backstick till the blades stopped. It could have been ugly, but ended up with the only scratch I ever put on a gyro , and I had it fixed and flying in 3 hours. I had procrastinated for a year with that new part ....not installing it like I should have. Several RAF's have been totalled from this one defective part.
                      Stan, thanks for mentioning the NW spindle.
                      Yes, I did change mine out, and your story helped compelled me to do so.
                      I'm glad that you and your dad weren't injured.

                      Your "RAF spindle" thread of
                      06-02-2005 is in the RAF board, thanks for that.

                      If a magnet won't attract to the circular NW spindle flange, then it's the original aluminum.
                      The steel shaft is prone to breaking at the roll pin.

                      Regards, Kolibri


                      PP - ASEL (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."

                      Comment


                      • #26
                        If you look at the way I design my cross bar, you will notice the rod ends are ergonomic to the movement and less bending stress to the rod ends.
                        Same with my idler arms and cyclic fork.
                        Life,The leading cause of Death

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

                        321.252.7705

                        Comment


                        • #27
                          That is a very clean set up Jake.

                          In my experience if the control rods are adjusted correctly on most control systems there is not much stress.

                          The challenge I am describing happens when they are not adjusted correctly or they are not the correct spherical rod ends for the application and the maximum misalignment is exceeded.
                          Last edited by Vance; 02-22-2018, 12:05 AM.
                          Regards, Vance Breese Gyroplane CFI http://www.breeseaircraft.com/

                          Comment


                          • #28
                            I have seen several failed control rod ends in RAFs.

                            All but one showed evidence of bending and in my opinion it was not due to the quality of the rod ends, the odd one appeared to have had the jam nut over torqued. The application did not call for misalignment capability so bending was unlikley.

                            I have not seen an RAF rod end fail at the eye in flight. I have seen some fail at the eye from over stress after an accident.

                            As I have written previously if I had an RAF I would probably replace the rod ends because I like quality hardware.

                            I do not have enough firsthand information to condemn all RAF spherical rod ends and do not claim to be an expert on anything to do with RAFs.




                            Regards, Vance Breese Gyroplane CFI http://www.breeseaircraft.com/

                            Comment


                            • #29
                              If you look at the way I design my cross bar, you will notice the rod ends are ergonomic to the movement and less bending stress to the rod ends.
                              Same with my idler arms and cyclic fork.
                              That looks like good engineering, gyrojake.
                              Big, fat, strong push tubes, too.
                              Which rod ends did you go with?


                              _________
                              I do not have enough firsthand information to condemn all RAF spherical rod ends . . .
                              We differ on how to view them.
                              To me, there is (since 2004) plenty of evidence to condemn them all, primarily because if any one of them breaks, a crash will ensue (likely fatal).
                              While most of them have held up, one can never know if a particularly bad part is in one's machine.
                              Why take such a demonstrated chance with $2 rod ends? It's nuts to do so.

                              Regards, Kolibri
                              PP - ASEL (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."

                              Comment


                              • #30
                                This thread is about putting spherical rod ends used in the control system of gyroplanes in bending and how to check for binding during preflight.

                                I have seen quality spherical rod ends break from being in bending.

                                I have seen people blame a spherical rod end failure on the rod ends when in my opinion it broke because it was in bending.

                                When I last replaced the spherical rod ends on The Predator it cost me somewhere north of $600 for the ten rod ends used in the control system.

                                Something I ponder is; once a spherical rod end has been put in bending it may not show the damage and yet it may have a crack that is very difficult to see and be working up to failing. In my opinion it is no longer airworthy.

                                In my opinion this rod end broke because it was put in bending. It appears to me to be a quality part. I do not have the paperwork.

                                Regards, Vance Breese Gyroplane CFI http://www.breeseaircraft.com/

                                Comment

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