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Official Freewing 90mm F-4 Phantom II Thread

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  • Hi everyone. I want to ask you all a question. I have done 4 flights with my new F4, and I have noticed that when turning right or left, it is quite abrupt and tends to keep turning, giving a strange and unpleasant sensation. Maybe you see it as normal, but for me, it is not. I have been in this hobby for 30 years, and this is my third EDF, and I have never noticed this behavior before. I have tried with less aileron travel, but I can't improve that response. Is this how it behaves? Is it an initial tendency to stall? The flights have been relatively calm to check the battery life, and I don't want to give it much speed for now...

    Comment


    • Hi Guillermo….
      Assuming your electronics are OK, the behavior you describe may be due to what is commonly referred to as “tip stall”. The wing that is on the inside of the turn travels a shorter path. The outside wing travels a longer path.

      A good analogy is a line of skaters on a rope going in a circle. The skaters closest to the center are SLOW compared to the skater on the outside/end of the rope.

      The inside wing in a turn may stall (going slower) and rapidly drop. Until that wing unstalls, no amount of aileron will raise it.

      So, how to mitigate this…..

      1) Release any up elevator you are holding. This reduces the wing’s angle of attack, and the wing will start flying again. Then the aileron can lift it.
      2) Fly faster. Airspeed is life! The wing is “farther” away from the stall speed. Add power as you enter the bank.
      3) Make more shallow banks. Steep banks exacerbate the “skaters on a rope” effect.

      We STRESS sooo much to our full-scale glider students to keep airspeed in the pattern, keep the yaw string straight, and don’t make steep banks down low.

      -GG

      Aside: Sailplanes on winch or auto tows or RC sailplanes on high start tows may suddenly experience a tip stall during the beginning of the tow as the nose comes rapidly up. Accidents have occurred as a tip stalls and that wing suddenly drops. No amount of aileron or rudder will raise the wing. If the pilot panics and freezes, recovery is not possible. The only recovery is RELEASE the back pressure, move the nose effectively “down” reducing the angle of attack. Then and only then will the steep bank be reduced.

      Comment


      • Originally posted by Guillermo View Post
        Hi everyone. I want to ask you all a question. I have done 4 flights with my new F4, and I have noticed that when turning right or left, it is quite abrupt and tends to keep turning, giving a strange and unpleasant sensation. Maybe you see it as normal, but for me, it is not. I have been in this hobby for 30 years, and this is my third EDF, and I have never noticed this behavior before. I have tried with less aileron travel, but I can't improve that response. Is this how it behaves? Is it an initial tendency to stall? The flights have been relatively calm to check the battery life, and I don't want to give it much speed for now...
        Hey G,

        Are using any rudder input while turning?

        Gotta keep your nose up and as GliderGuy nailed it, you must keep up your speed, as well.

        This is much like the 1:1.

        Best, LB
        I solemnly swear to "over-celebrate" the smallest of victories.
        ~Lucky B*st*rd~

        You'll never be good at something unless you're willing to suck at it first.
        ~Anonymous~

        AMA#116446

        Comment


        • Ime intermediate pilot. And have around 40 flights on this now.. a mix of 6 and 8s.. feel very comfortable now..
          I'm not as tech savvy as the above fellas.. first flight flew it fast.. as I got more. Comfortable,,and started slowing it down. I had a couple similar instances just like that..like an uncommanded roll.. in the turn.... Now I do not slow it so much in turns.
          And keep up the speed. In a larger pattern.
          Vwala has not happened again.


          In short the simpleton (that's me). Opinion is as above.
          Sppeeed.

          It's not a Cessna .. it's meant for speed and doesn't glider guy give the best tech information


          Comment


          • Originally posted by Guillermo View Post
            Hi everyone. I want to ask you all a question. I have done 4 flights with my new F4, and I have noticed that when turning right or left, it is quite abrupt and tends to keep turning, giving a strange and unpleasant sensation. Maybe you see it as normal, but for me, it is not. I have been in this hobby for 30 years, and this is my third EDF, and I have never noticed this behavior before. I have tried with less aileron travel, but I can't improve that response. Is this how it behaves? Is it an initial tendency to stall? The flights have been relatively calm to check the battery life, and I don't want to give it much speed for now...
            I have not experienced this behavior with my F-4 and I've been flying it for a couple of years. That said I do have a gyro in this plane and every plane I have. The plane is fast, and slow, no issues.

            Comment


            • Takeoff and Landings with the F-4

              https://youtu.be/b7Fg6tSbCKw​​

              Comment


              • Grossman56

                Pics for your pilot painting library.

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                I solemnly swear to "over-celebrate" the smallest of victories.
                ~Lucky B*st*rd~

                You'll never be good at something unless you're willing to suck at it first.
                ~Anonymous~

                AMA#116446

                Comment


                • Long ago and far away. He was the man.

                  Comment


                  • Elbee
                    Elbee commented
                    Editing a comment
                    Yes, Sir, he was "the Man". Another true American Hero.

                • Originally posted by jetpltrich View Post
                  Takeoff and Landings with the F-4

                  https://youtu.be/b7Fg6tSbCKw​​
                  SWEEEET!
                  Hugh "Wildman" Wiedman
                  Hangar: Mig 29 "Cobra", 8S EuroFighter-Bronze Tiger, A-10 Arctic, F18 Canadian & Tiger Meet, 8S F16 Wild Weasel, 8S F4 Jolly Rodgers & Blue Angel, 1600 Corsair & Spitfire, B-24, Stinger 90, Avanti. Extreme Flight-FW-190 Red Tulip, Slick 60, 62" Extra 300, 62" MXS Heavy Metal, 62" Edge Demonstrator. FMS-SU-30,1700mm P-51, Corsair, Viper, Beast Bi-Plane 60", P2 Bi-Plane, P51.

                  Comment


                  • Ew, that's scary especially the third and fourth pic...

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                    I think I got a good likeness, man, I didn't know he had a gold helmet, something just said, "paint it gold" so I did.

                    Grossman56
                    (Dangerous Dan)
                    Team Gross!

                    Comment


                    • Dangerous,

                      Looks like I will be needing your services for Toledo 26. I beat the tariff increase yesterday from Motion. You guys are killing me! LOL.
                      Hopefully Dave can get involved also. Later
                      Best Regards, Rex

                      Comment


                      • I am not sure what I am doing wrong. Using the serch function to try to locate info on the elevator rod repair/mod. Can someone provide some direction for this old guy?

                        Thank you

                        Comment


                        • More pictures and info on RCG... I used 4-40 rod and a stronger/ larger ball link.

                          Comment


                          • Originally posted by dawhale View Post
                            I am not sure what I am doing wrong. Using the serch function to try to locate info on the elevator rod repair/mod. Can someone provide some direction for this old guy?

                            Thank you
                            DW,

                            Welcome to Hobby Squawk.

                            Glad to have you onboard.

                            What Evan D wrote is good information.

                            Replacing the OEM Rod(s) with 4-40 all thread or linkage is the way to go.

                            Some, like myself, also added a carbon fiber tube over the 4-40 all thread and I glued it with CA after I liked the positioning.

                            The ball links are also the way to go even if need to drill out your servo arm or even replace it with something stiffer.
                            I added a Futaba (or equivalent) higher torque servo.

                            You get the general idea, it is a matter of stiffening the linkage rods and attachment hardware to remove the play in the OEM setup.

                            Best, LB
                            I solemnly swear to "over-celebrate" the smallest of victories.
                            ~Lucky B*st*rd~

                            You'll never be good at something unless you're willing to suck at it first.
                            ~Anonymous~

                            AMA#116446

                            Comment


                            • Can someone point me in the right direction to add opening canopies to the F-4. Researching for future project. Thanks in advance.

                              Best Regards, Rex

                              Comment


                              • I bought a used Freewing F4. One elevator was loose. I removed the bottom of the fuselage and found a bent servo push rod. I understand the need to upgrade the servo linkage. Is there a mod to stop the set screw from slipping on the elevator connecting rod?

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                                Comment


                                • Take a dremel and grind a flat on the shaft.

                                  Comment


                                  • My pushrod fix was less glamorous than above.. I used the original rod.. cut 2 more rods and the smallest carbon rod that would go over the then 3 rods.. and filled internally the carbon rod with epoxy... I like simple tricks,, (cause I'm simple) lol.. here's one from RC informer... While moving the control surface,, a little super glue in the servo and horn holes ,with control rods in place, will take out that last slop...... Even with my new hi teck servo I could move by the elevator 1 or 2 mm (slop by hand).now none,, and U can do that as ref maintenance,, JUST B SURE TO. MOVE. Control surface until Supa glue is dry... For obvious reasons..
                                    As regards the set screw,, I filed a tiny flat on the rod.. it took a bit to get the elevator half's to match,, but well worth it.. have fun,, it flys great,,, especially on 8s.. keep up speed in turns ,, lastly epoxy or support some how the elevator servo.. mine was loose after 2 flights

                                    Comment


                                    • Sorry did not see that Evan suggested a flat on the rod

                                      Comment


                                      • F4uausie,
                                        My next project arrived. A beautiful F4 Phantom. 6s Grey Ghost.
                                        Best Regards, Rex

                                        Comment

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