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Official FlightLine F4U-1A Corsair 1600mm (63") Wingspan

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  • Originally posted by themudduck View Post
    Yeah seconded Hardway!

    When Hugh said his gear "still worked (although very uneven and shaky)" ... well I thought that I would mention, I've noticed that when the retract acts like that it is often because the plastic case is cracked open (or the jack screw is bent). I've replaced the retract unit a few times and on each one the plastic case was cracked. I'm getting used to landing this bird properly but the OEM unit seems to break quite easily and I really wish we had a metal-case retract unit for this plane. If anybody finds one that will fit, please let us know!
    I can make a case pretty easy, the issue is now the force is being transferred to the wing/servo pocket and will find the next weakest part in the system.
    Planes
    -E-Flite: 1.2m P-47, Maule, Turbo Timber, 1.5m AT-6, 1.2m T-28, Dallas Doll, Viper, F-15, F-16, Wildcat, Carbon Cub -UMX: Mig-15, Pitts, Timber
    -FMS: Bae Hawk Motion: 1.6m Corsair, 850mm Mustang, 1.6m Spitfire Freewing: 1.7m A-10, F-22,

    Comment


    • Originally posted by thisguy65 View Post

      I can make a case pretty easy, the issue is now the force is being transferred to the wing/servo pocket and will find the next weakest part in the system.
      An 1/8in aluminum plate small bolts with lock nuts on 4 corners. Glue in 4 cut springs in the middle and attach it to the underside of the casing. Or even with a squish foam between. Would easily absorb 1/4 of the impact force. What we have right now is a spring loaded strut, now add a coilover to it. Damn...now you guys have me thinking. That's bad. Easy now...nevermind the shock plate. All it needs to absorb more impact is a stiffer spring in the strut. Hell...that might solve half these issues. Springs spread the load of impact. These planes are sometimes hammered into the ground. The spring is obviously insufficient at absorbing that much force and redirecting it. Off road and race vehicles use larger caliber springs to offset impact and redirect it through the spring. There are even springs that can be tuned for more/less force. I will look into it unless one of you is semi retired and want to measure and MIC the spring in a strut and find a heavier one. That would be faster...as you can see I have too much "****" in my head and might even forget. lol

      Comment


      • Stiffer spring translates more force directly in to the mount. The torque moment force of the gear being slammed in the ground is breaking the housing. The fact the gear is so long means less force is needed to break the retract case. I already may/may not have the retract body in CAD. What you are describing regarding racing is a progressive spring rate vs the factory linear.
        Planes
        -E-Flite: 1.2m P-47, Maule, Turbo Timber, 1.5m AT-6, 1.2m T-28, Dallas Doll, Viper, F-15, F-16, Wildcat, Carbon Cub -UMX: Mig-15, Pitts, Timber
        -FMS: Bae Hawk Motion: 1.6m Corsair, 850mm Mustang, 1.6m Spitfire Freewing: 1.7m A-10, F-22,

        Comment


        • Originally posted by thisguy65 View Post

          I can make a case pretty easy, the issue is now the force is being transferred to the wing/servo pocket and will find the next weakest part in the system.
          I feel you are 100% correct. You go down the road of making something stronger (which adds weight) and then something else breaks. So you make that part stronger (and heaver) and something else breaks. There is a tradeoff to consider, and the trick is finding the sweet spot I guess - you want these things to be "stong enough". Sometimes having something small break right off (like the landing gear) can save something else (like the wing). But I am tired of replacing those cases....
          Maybe we should just buy a bunch of replacement cases and chill!
          Marc flies FW & FL: AL37, MiG-29, T45,F4, A4, A10, F104 70 and 90, P38, Dauntless SBD, Corsair, B17, B24, B26 & P61, Lipp.P19, ME262, Komets, Vampire, SeaVixen, FMS Tigercat, FOX Glider & Radian XL.

          Rabid Models foamies, including my 8' B17 & 9' B36... and my Mud Ducks! www.rabidmodels.com

          Comment


          • Originally posted by thisguy65 View Post
            Stiffer spring translates more force directly in to the mount. The torque moment force of the gear being slammed in the ground is breaking the housing. The fact the gear is so long means less force is needed to break the retract case. I already may/may not have the retract body in CAD. What you are describing regarding racing is a progressive spring rate vs the factory linear.
            Sorry man. Disagree a little but it's a good start to the discussion. I am a mechanical engineer so I tend to overthink..on occasion..lol The spring is there to dissipate energy . Reaction can be measured in energy lbs or oz's easier in this situation. Torque is measured side to side (twist) movement or stretch. We are not dealing with stretch here we are dealing with compression. The strut has a weak point where the stop rod runs through it. If too much energy makes it to that point it breaks at the weakest spot due to compression energy being too great. The springs entire job is energy dissipation. When you dissipate energy in a straight line it is bled off and returned to the universe. A stiffer spring will dissipate the energy faster..there will be a sweet spot of course. If the reaction force is slowed at an earlier point the strut's weak spot will not have as much energy hit it at once. Aluminum is quite pliable and has good memory for such a soft metal. It's when they mix too much cheap nickel in it that it gets brittle. So if the energy can be dissipated by even 20% it should make one hell of a difference on the casings and strut rod's lifespan. I didn't measure the compression lbs but I did push the strut on my FMS Redtail and pushed on the Corsair...I bet there isn't a 4oz difference between the two spring rates if there is any at all. There should definitely be a HUGE difference in spring resistance. That little FMS bird weighs half of what the Corsair does.

            Comment


            • Originally posted by prestonowtm View Post

              Sorry man. Disagree a little but it's a good start to the discussion. I am a mechanical engineer so I tend to overthink..on occasion..lol The spring is there to dissipate energy . Reaction can be measured in energy lbs or oz's easier in this situation. Torque is measured side to side (twist) movement or stretch. We are not dealing with stretch here we are dealing with compression. The strut has a weak point where the stop rod runs through it. If too much energy makes it to that point it breaks at the weakest spot due to compression energy being too great. The springs entire job is energy dissipation. When you dissipate energy in a straight line it is bled off and returned to the universe. A stiffer spring will dissipate the energy faster..there will be a sweet spot of course. If the reaction force is slowed at an earlier point the strut's weak spot will not have as much energy hit it at once. Aluminum is quite pliable and has good memory for such a soft metal. It's when they mix too much cheap nickel in it that it gets brittle. So if the energy can be dissipated by even 20% it should make one hell of a difference on the casings and strut rod's lifespan. I didn't measure the compression lbs but I did push the strut on my FMS Redtail and pushed on the Corsair...I bet there isn't a 4oz difference between the two spring rates if there is any at all. There should definitely be a HUGE difference in spring resistance. That little FMS bird weighs half of what the Corsair does.
              So do I, lol! We both agree springs could help the issue at hand. I use to be a ME before switching to hydraulics for Caterpillar. I’ve got a small machinist shop here at myhouse. China has always had..not so great alumn. Customers will hand me prints that say “American (grade) only” And another reason why China cheap hardware is consider soft. Even when using the correct drivers. The critical part of the failure not mention is the struts are not vertical when coming for a landing. They are raked out, much like a eagle about to catch dinner. When I mention the torque (twisting force) moment arm, it is viewed from side of the plane. Let’s said from planes right view. Plane is moving left to right, sink rate is high. When wheels touch at high sink rate the springs only compress a little (over sprung) directing the force in the retract body’s f opposite back in to the ground. Due to the length of the struts it takes considerable less force to break the body.



              I’ve broken a set and designed a alum side plate. Then realize the servo pocket would be the next thing to crack or get ripped out, causing me to abandon the metal plates and look at re-springing it. The other issues is some struts are not machined well thus snag on one self while compressing. A lot of these planes are over sprung from the factor. Example, look at the A-10 F/W. Placed on the ground with 400 grams of batteries on the ground, push the nose down, even half travel and let go. The front wheel will come off the ground a good 1-5”-2”-2.25”. I cut the spring down 3/8 lowering its max rebound force. To much of a stiff spring will make the plane bounce. A progressive spring ideally would be great but someone having the time and ability to do the testing is asking a lot. I plan to test cutting the spring and seeing how well the plane liked the changed but time is limited w/ a 6 month old. Heck we have s hurricane passing over us now lol.
              Planes
              -E-Flite: 1.2m P-47, Maule, Turbo Timber, 1.5m AT-6, 1.2m T-28, Dallas Doll, Viper, F-15, F-16, Wildcat, Carbon Cub -UMX: Mig-15, Pitts, Timber
              -FMS: Bae Hawk Motion: 1.6m Corsair, 850mm Mustang, 1.6m Spitfire Freewing: 1.7m A-10, F-22,

              Comment


              • was once a aircraft structural egr. hard points are made by gradually increasing strength by tying in large soft areas to the hard point. foamies do this by using a adhesive that fills all the gaps between the ABS hard point and the foam. I can't believe it works! but it does.

                standard oleos are sprung to the wt of the vehicle, so for our f4u's each strut can exert ~8# of force. the springs function is to increase the time the force acts on the plane. as the time the force has to act is increase the max force the hard point sees is reduced, the problem is that if more than ~8# is applied to the strut the spring assembly "bottoms out" ,from that point on the full force of the landing is on the mechanism above the spring, that's when it breaks. adding a heavier spring would reduce the time the force acts over, increasing the max force for normal use, forcing the rest of the mechanism to endure this higher normal.

                not being the one who designed it, and seeing for the most part it fails after a stal,l only. I would conclude that it works correctly if use correctly. would I like it to be more robust? always! but at what cost? these planes fly great!

                Joe
                Platt: fw190d9 Dynaflite:PT-19 IMP:Macchi202 ESM:fw190 ESM:Tank, Hien Jackson:DH-2 BH:macchi200 Extr:fw190 Holman:me109F H9spit2 FL:F4u,spit 9 FW:me262 GP:us60, Stuka, cub, F4u PZ:me109, albi EF Hurri, T-28 FMS: 2x fw190, me109 Lone Star:Skat Kat RSCombat:2xfw190d9

                Comment


                • Great flying machine! Last weekend was the maiden flight plus three more. Specs per manual. I have an Admiral 6 channel receiver w/gyro in this Corsair. It was windy at the field today and the gyro worked wonders! A+++’s to MotionRC for bringing this Warbird to us. Graphics courtesy of Callie-Graphics.

                  Comment


                  • Originally posted by paladin View Post
                    was once a aircraft structural egr. hard points are made by gradually increasing strength by tying in large soft areas to the hard point. foamies do this by using a adhesive that fills all the gaps between the ABS hard point and the foam. I can't believe it works! but it does.

                    standard oleos are sprung to the wt of the vehicle, so for our f4u's each strut can exert ~8# of force. the springs function is to increase the time the force acts on the plane. as the time the force has to act is increase the max force the hard point sees is reduced, the problem is that if more than ~8# is applied to the strut the spring assembly "bottoms out" ,from that point on the full force of the landing is on the mechanism above the spring, that's when it breaks. adding a heavier spring would reduce the time the force acts over, increasing the max force for normal use, forcing the rest of the mechanism to endure this higher normal.

                    not being the one who designed it, and seeing for the most part it fails after a stal,l only. I would conclude that it works correctly if use correctly. would I like it to be more robust? always! but at what cost? these planes fly great!

                    Joe
                    Got it on the 8lb. Spring compression on the FMS 1400 p-51 and the Corsair in question were both a nominal 5.1628 1b and 5.2412 lb. The corsair strut compression was really sticky unless it was exactly 90dg. So with both numbers put together the Corsair is under sprung by quite a bit. Virtually the same spring in both planes.

                    Comment


                    • Hey Guys...I only had 16 flights on my Corsair from when I first bought it back in May and was out with it today, enjoying some new batteries and getting to know the plane again. I had five great flights in and was just finishing up the sixth and final flight after a couple of touch and go's. I turned on final with gear and full flaps deployed, and sensed things were feeling mushy. I added throttle, but felt like there wasn't anything happening. As it slowed and the wings began to wobble I was still adding more power and trying to correct with ailerons, but felt nothing. It went into a spin that I couldn't recover from. As much as I would love to blame it on something, I couldn't find anything mechanical to suspect. The receiver light was solid, the battery had 30+% left, all the control surfaces were working (except the elevator, which was unplugged and I'll never know if that happened before or after), and my transmitter had plenty of charge. It is a total loss, and to add insult to injury, the brand new battery is toast as well.

                      So, my personal lessons learned are: 1) do not deploy full flaps until on final, 2) add more power while turning to final as a rule (especially on the Corsair), 3) read a reminder in my pre-flight book on every trip to the airfield, reminding myself when in an emergency to always drop the throttle completely and bring it back up (just in case there is a brown-out). That wasn't the case here, but I kicked myself for not doing that procedure instinctively! So this was my first crash in 3 years and 3 months...it still hurts, but I guess nobody gets away completely unscathed. It's an awesome bird and no doubt she will be replaced in the hanger! Rob

                      Comment


                      • That just sounds like more than just a stall. I can fly around all day with the gear down and full flaps with 40% throttle without stalling. If you noticed it was beginning to stall and added throttle, it should have responded relatively quickly. Does sound like a brownout.
                        Hugh "Wildman" Wiedman
                        Hangar: FL/FW: Mig 29 "Cobra", A-10 Arctic, F18 Canadian & Tiger Meet, F16 Wild Weasel, F4 Phantom & Blue Angel, 1600 Corsair & Spitfire, Olive B-24, Stinger 90, Red Avanti. Extreme Flight-FW-190 Red Tulip, Slick 60, 60" Extra 300 V2, 62" MXS Heavy Metal, MXS Green, & Demonstrator. FMS-1700mm P-51, Red Bull Corsair. E-Flite-70mm twin SU-30, Beast Bi-Plane 60", P2 Bi-Plane, P-51.

                        Comment


                        • Originally posted by RCAV8R View Post
                          Hey Guys...I only had 16 flights on my Corsair from when I first bought it back in May and was out with it today, enjoying some new batteries and getting to know the plane again. I had five great flights in and was just finishing up the sixth and final flight after a couple of touch and go's. I turned on final with gear and full flaps deployed, and sensed things were feeling mushy. I added throttle, but felt like there wasn't anything happening. As it slowed and the wings began to wobble I was still adding more power and trying to correct with ailerons, but felt nothing. It went into a spin that I couldn't recover from. As much as I would love to blame it on something, I couldn't find anything mechanical to suspect. The receiver light was solid, the battery had 30+% left, all the control surfaces were working (except the elevator, which was unplugged and I'll never know if that happened before or after), and my transmitter had plenty of charge. It is a total loss, and to add insult to injury, the brand new battery is toast as well.

                          So, my personal lessons learned are: 1) do not deploy full flaps until on final, 2) add more power while turning to final as a rule (especially on the Corsair), 3) read a reminder in my pre-flight book on every trip to the airfield, reminding myself when in an emergency to always drop the throttle completely and bring it back up (just in case there is a brown-out). That wasn't the case here, but I kicked myself for not doing that procedure instinctively! So this was my first crash in 3 years and 3 months...it still hurts, but I guess nobody gets away completely unscathed. It's an awesome bird and no doubt she will be replaced in the hanger! Rob
                          Sorry for your loss "so sad", it was very difficult to watch this tragedy happen.

                          Please remember that all pilots eventually \will experience a flight that gives you no suitable exit....

                          Your flying friend
                          Rich

                          Comment


                          • That is true! So......... re order! I remember the building days..... 6 to 12 months later, you were back flying. Not so much now.

                            Comment


                            • Still a bummer. Did the ESC overheat? Just a thought. Jerry

                              Comment


                              • We didn't check that Jerry, though we didn't pick up on that as we were handling it after the crash. Rich (Richj53) was there, along with others, and there was an extensive post mortem to try and find a cause. I agree with Hugh's earlier post and believe I had enough sense to give the appropriate throttle. Another thought I had was that the receiver (Spektrum AR6210 with satellite) came from my Spit after a somewhat similar incident that fortunately happened much closer to the deck while landing. I sent it back to Horizon and had it bench tested before installing it in the Corsair. But, if it was the receiver, wouldn't I have had a blinking light indicating an interruption? Rob

                                Comment


                                • You should have had the light blinking..... But with a brownout, I lost all servo control as well as throttle. When the ESC got too hot, I still had servo control, but just no throttle, so that is why I asked. You said it was flight six if I remember, so how much time has passed between batteries? Just throwing thoughts out there to make it harder Bro!!! LOL That is why I always use an external BEC and not the one in the ESC, and it has worked so far!!!! I hope it keeps working!!! LOL Blessings bud!

                                  Comment


                                  • OK guys, not sure this is the right place, but since we're talking brownout, I'm not really sure what causes them, so here is my issue. Just finishing a 90mm F-16, installed the in runner 4068-1835 kv and the 155amp gecko ESC (never used this brand before), and while testing the stearing out to keep it straight, I jogged the throttle up and down in short bursts to watch how it tracked. Twice the throttle stopped working, had to drop it down and it re-initialized, beeped 6 times and started to work again. I reprogrammed the full and low throttle points, seemed to work OK, but did it once again. On the bench, if I "jog" the throttle up and down quickly with bursts of low speed, it will occasionally stop working again. Granted, I don't fly this way, but it scares the hell out of me when I'm going to maiden this thing next week and there might be an issue with the ESC or something else. The servos still work so this is some sort of a brownout. Any thoughts? Never had this issue, so maybe should have stuck with the FL ESC or my beloved Castle ESC.
                                    Hugh "Wildman" Wiedman
                                    Hangar: FL/FW: Mig 29 "Cobra", A-10 Arctic, F18 Canadian & Tiger Meet, F16 Wild Weasel, F4 Phantom & Blue Angel, 1600 Corsair & Spitfire, Olive B-24, Stinger 90, Red Avanti. Extreme Flight-FW-190 Red Tulip, Slick 60, 60" Extra 300 V2, 62" MXS Heavy Metal, MXS Green, & Demonstrator. FMS-1700mm P-51, Red Bull Corsair. E-Flite-70mm twin SU-30, Beast Bi-Plane 60", P2 Bi-Plane, P-51.

                                    Comment


                                    • Originally posted by Hugh Wiedman View Post
                                      OK guys, not sure this is the right place, but since we're talking brownout, I'm not really sure what causes them, so here is my issue. Just finishing a 90mm F-16, installed the in runner 4068-1835 kv and the 155amp gecko ESC (never used this brand before), and while testing the stearing out to keep it straight, I jogged the throttle up and down in short bursts to watch how it tracked. Twice the throttle stopped working, had to drop it down and it re-initialized, beeped 6 times and started to work again. I reprogrammed the full and low throttle points, seemed to work OK, but did it once again. On the bench, if I "jog" the throttle up and down quickly with bursts of low speed, it will occasionally stop working again. Granted, I don't fly this way, but it scares the hell out of me when I'm going to maiden this thing next week and there might be an issue with the ESC or something else. The servos still work so this is some sort of a brownout. Any thoughts? Never had this issue, so maybe should have stuck with the FL ESC or my beloved Castle ESC.
                                      Hugh...................The Gecko's have had a known history of throttle response issues (timing issues) which there is a firmware fix for it.
                                      MotionRC support pages for all the ZTW Gecko devices have the link.
                                      Here's the support page link to the 155A Gecko.........https://www.motionrc.com/collections...ec#support-tab
                                      It is labeled as "ZTW GECKO 85A ESC PC Firmware Update (ZIP file)" but it is actually for ALL the devices.
                                      Here is some valuable info from over on RCG to help with the " possible timing issue you may be having."
                                      https://www.rcgroups.com/forums/show...-timing-issues

                                      Best regards,
                                      Warbird Charlie
                                      HSD Skyraider FlightLine OV-10 FMS 1400: P-40B, P-51, F4U, F6F, T-28, P-40E, Pitts, 1700 F4U & F7F, FOX glider Freewing A-6, T-33, P-51 Dynam ME-262, Waco TF Giant P-47; ESM F7F-3 LX PBJ-1 EFL CZ T-28, C-150, 1500 P-51 & FW-190

                                      Comment


                                      • Hugh, you might need this too:
                                        https://www.motionrc.com/products/ztw-lcd-esc-programming-card

                                        Comment


                                        • My 85 amp gave me fits for a little while in my P-47...

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