Freewing F-105 64mm EDF Jet - PNP

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Official Freewing Twin 70mm AL37 Airliner Thread

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  • Originally posted by Rogerio Pereira View Post
    Hi folks, I would like to ask the question related to the use of TWO 6000 packs to extend the flying time, will the wings take the extra weight without issue? I expect landing speed will be higher, but, how mutch? Balance the plane should not be an issue if I make a new battery support base to extend further back, my main question for anyone out there is if the model can be run in this power configuration without structural issues, appreciate if any of you could reply.
    enjoy your models and fly safe.
    Rogerio Pereira
    Hi Rogerio - The structure of the AL37 has been proven by the other posts showing 4 engines flying successfully and others posting here and on YouTube about flying with 2 batteries.

    Your question to yourself should be, “How do I intend to fly the AL37?” Added weight and structure stress means severe limitation on any aerobatics and speed. You’ll be much safer flying around in a slower scale manner (avoid high speed dives) and not flying off of rough surfaces due to the added stress on the gear.

    Adding weight = self imposing restrictions
    Speed and acro = stress on a structure compounded by more weight
    Worst case for stress = increasing the weight of the non-flying parts of the aircraft
    Steep banks = more stress

    When we add several hundred pounds of water ballast in the wing tanks of the sailplanes we fly to improve the glide ratio at a given speed, we must dump the water before landing or risk breaking the landing gear....and NO ACROBATICS!

    Reference my prior post #1893...adding weight to the fuselage will also likely accelerate the foam cell boundary cracking I experienced on the wing's topside after many, many flights due to the added stress on the wing caused by the added weight.

    -GG

    Photo of a sailplane dumping water ballast prior to landing...
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    • Adding weight = self imposing restrictions
      Speed and acro = stress on a structure compounded by more weight
      Worst case for stress = increasing the weight of the non-flying parts of the aircraft
      Steep banks = more stress Hi, GG,
      Thanks for the reply, and yes I agree 100% with you on your note -. No Aerobatics- My flying style with this model is scale like as much as possible, and with this one even more so, it does not look right flying the AL 37 inverted or performing bomb dives, I have other models for that, I was not sure if the addition of another couple of pounds in the fuselage was not going to compromise the integrity of the plane while flying scale like, but I guess it was already answered on other posts, ( did not read all of them).
      My plan is to add another 6S 6000mah pack to enjoy a little more flying time, I fly off an active aerodrome with smooth blacktop runway, the other addition planned is wheel brakes, but there I am looking at home made passive magnetic brakes in the wheel hubs to avoid the use of more power, it will only require the addition of one opto switch to activate, the added weight is minimal and no risk of stopping a wheel as it only brakes if the wheel turns above a certain low speed. Will post some pic's and vid's when I get back from work and complete the installation in a couple of months.
      Thanks again.

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      • Noted GG, and thanks.

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        • Rogerio "Noted GG, and thanks." / (Reference my prior post #1893...adding weight to the fuselage will also likely accelerate the foam cell boundary cracking I experienced on the wing's topside after many, many flights due to the added stress on the wing caused by the added weight.)

          Adding / FedEx notification just received for a "today" delivery of my new AL37. Woo Hoo! I'm going to attempt to engineer some internal bracing to the topside skin area of the wing that has been shown (on my bird #1) to be prone to foam cell boundary cracking (due to flexing) . Or...I may decide to add a layer of glass externally to the topside of the wing. But, I'd rather not get into a sanding/repainting job on the wing, if possible.

          We'll see how it goes. I'm not overly concerned about the wing structure (with the cracks), but it is not pretty...and everyone comments about the cracks when they see them. UGH. I want to avoid having the cracks re-appear on the new bird. The strength is in the carbon rod...not the skin.

          Here is an ENHANCED CONTRAST photo of the cracks on Bird #1....after 1000+ flights / normal and aerobatic flying (I didn't quite match the original paint when I attempted to fix these the first time they showed up). Note: There are no cracks on the bottom wing skins. Raised bump/nature of the areas around the cracks indicate compressive stress in the skin likely resulting from loops and recovery from spins.

          Again, Bird #1 is being retired.

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          -GG

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          • Update to Post #1904....

            New bird is ready to go! Hope to maiden Bird #2 this afternoon, if the winds cooperate.

            I was able to add a span-wise reinforcing carbon rod stringer in the wiring channel in the area which was found to fatigue crack in Bird #1. Remains to be seen if this is successful.
            -GG

            Update - Maiden was a success! Needed about 3 clicks of up trim is all. Flies GREAT!

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            • Click image for larger version

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ID:	294367 Hi,
              Hello at all from Germany

              I'm now also a AL37 owner. Bought it in white and designed it with the help of callie in two airlines.
              The right side Ryanair and the left side SunExpress.
              The reason is, our son took the Ryanair EI-DHP factory new by Boeing in Seatlle and with the SunExpress D-ASXD he was the first to be allowed to use the callsign sunrise .

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              • Nok Air Thailand low cost carrier. Nok Cartoon Livery. Maiden soon. Click image for larger version

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