Announcement

Collapse
No announcement yet.

Thrust Numbers

Collapse
X
  • Filter
  • Time
  • Show
Clear All
new posts

  • #31
    Yes, I think it's the extra labor and skills involved.

    It's POSSIBLE to build an open-frame tractor gyro in a Bensen-like config; putting it crudely, you move the engine forward to the (former) pilot area and sit the pilot behind the mast, where the engine was. A couple examples of this were the Ikenga and the Jeri-copter (both covered in the PRA mag 20-ish years ago). The Ikenga, at least, flew.

    The disadvantages of this setup, however, are horrendous. The noise, exhaust heat and 100 mph slipstream blast of the engine all bathe the pilot in joy. Your feet will poke into the prop in a frontal crash. Even worse, that slipstream blast hitting open frame elements and exposed pilot creates a huge drag penalty -- at 50 mph at wide-open throttle, about four times higher than the drag of the same pilot and frame elements in the pusher config.

    So rational designers build an enclosed, streamlined fuselage behind the tractor prop. This involves either a fiberglass "boat," good aircraft sheet-metal work a la Cessna, welded tube and rag, or perhaps aluminum angle/tube and rag. All involve quite a bit more skill and time to build than a Bensen erector-set rig, though you end up with something that many see as more elegant and valuable.

    For some of us, the wide-open, flying lawnchair sensation is most of the fun of a gyro anyway. I'd love to have a Little Wing, though, if I had three or six Bensens' worth of time on my hands to build it.

    Comment


    • #32
      I seem to remember a tube frame tractor gyro that was like a bensen but with two tails, a seat behind the mast and the engine out front in a nice streamlined cowling, I think it was from tennessee,this would have been about 1973 to 75 but I don't know if it ever flew but it sure looked different than the gyros of the day.

      Norm

      Comment


      • #33
        Norm,

        Perhaps you are thinking of the Ikenga 530Z

        Wayne
        Attached Files

        Comment


        • #34
          that is not the one, the one that I am thinking of mac powered and was built in the 70s.

          Norm

          Comment


          • #35
            tractor gyro

            this is very interesting,the original little wing first flew without fabric cover with mac engine,also there is French tractor I believe flying with 503 ,the video can be found on youtube,another example would be Russian barsik which succesfuly fly with simonini victor engine ,so all these gyroplanes fly on 50 hp +- ,I don't know about mac I personaly don't believe it has 72 hp with regular 100 ll gas
            Attached Files

            Comment


            • #36
              tractor

              here is the link for tractor above

              https://www.youtube.com/watch?v=7Soz4ap34is

              Comment


              • #37
                By placing the propeller at the front, we can choose a larger diameter. So the performance is better. Unobstructed, the engine can dispense with its cooling fan. Several more HP then become freely available for propulsion. Also, Completely eliminate the suction drag at the rear of the fairing is easy. Many HP are no needed during cruise level. Because of all this, not much additional wind on the windshield.
                The propeller is also much quieter since it works in undisturbed air. In addition, pebbles lifted from the track by the wheels can no longer reach, and she is more likely to caught up various objects accidentally fallen in flight (mobile phone, car keys, helmet visor, etc.), with consequences sometimes dramatic.
                In the event of a frontal impact, the engine is a shield for the driver, instead of a projectile traitor. Just my theoretical opinion on the tractive propeller.

                Comment


                • #38
                  I know I'm tired of flying small gyro's with just enough HP to fly. With a climb rate of less than 100 ft min. When building, if it's only a few hundred more to get a bigger engine, just do it.
                  http://gyroplanetraining.com/

                  Helping Plan a grand 2017 PRA convention


                  PRA BOD # 38604

                  Comment


                  • #39
                    Theoretical advantage of tractor

                    Comment


                    • #40
                      I've seen several posts that discuss the theoretical advantages of tractors over pushers, but real world flying examples like the Wallis gyros, the Hinchman racer and especially the Carlinator all have very high performance that aren't outperformed by tractors much, if at all.

                      It's interesting that the 2 gyros competing for most of the records are so far apart in design. The short propped pusher Wallis's and the comparably long propped tractor Little Wing.

                      I still believe the most efficient gyro ever built is the Carlinator. It flies the most weight with the least HP at the fastest speeds with the lowest fuel burn of any gyro.
                      "Nothing screams poor workmanship like wrinkles in the duct tape!"
                      All opinions are my own, I've been wrong before and I'll be wrong again. Feel free to correct me if I am.
                      PRA# 40294

                      Comment


                      • #41
                        And carl flys at high density altitudes with me here in socorro NM.,and he flys really well.

                        his gyro is very unique and represents carl's mechanical abilitys very well. It also has a

                        very nice sound when in the air.

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

                        Comment


                        • #42
                          I wonder if that top post #35 showing the tractor gyro with the 3-bladed rotor has flown and if so, how well?

                          The rotor appears to be controlled like any gimble headed gyro, except the blades have a flapping-hinge close to the rotor's center.....may still require a strong arm while maneuvering.
                          There doesn't appear to be any lead/lag hinge though....overall an interesting design.
                          Ed Rosenberger

                          Comment


                          • #43
                            is this yellow tractor now flying ?

                            Comment


                            • #44
                              In about 1987,,,,,,,my Bensen Gyro .....72 HP Mac,,,,,,Expansion Chambers thrust was 340 Lbs. Weight was about 285,,,,,,,me,,,,added on to it was about 175 Lbs.....
                              So,,,,,,,,460 Lbs,,,,,,,,,and forgot to add fuel,,,of about 45 Lbs,,,,making all total about 505 Lbs....
                              My thrust again was 340 Lbs,,,,,
                              My Bensen Mac performed very well by the way,,,,and still does,,,,,,,,
                              Propeller was a 52X26 Culver and it was the design similar to a typical airplane/fixed wing prop and not like the Troyer types of that being like a " Paddle" Prop
                              Last edited by Ron Iaconis; 04-26-2017, 07:28 AM.
                              Ron Iaconis

                              Comment


                              • #45
                                340 sounds pretty good for a 72. I will do a thrust test on my 90 when I have time
                                David Bacon

                                Comment

                                Working...
                                X