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Official Freewing MiG-29 Fulcrum Twin 80mm Thread

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  • Originally posted by Gringotuerto View Post
    [FONT=Arial][SIZE=12px]1. Anybody else using the Admiral 5000mah that MotionRC sells?

    2. It is not easy to balance with the 5000x50C. They are pretty long, so for the rear one you have approximately zero wiggle room – it fits where it fits. For the front one, I found that if you place it on the top, and hang it over the front edge of the battery tray, just to the point where it bumps up against the back of the pilot’s seat, then the plane is only about <1cm tail heavy (vs. the marked CG), which seems like what most people are recommending anyway. At least that’s how mine works out, ymmv. I have the new elevator servos in, for example, which are a slight bit heavier, and I also modified the cockpit a slight bit.
    I noticed that myself as well earlier this week when I began setting up my A/C. One in the back, the other on the middle tray overhanging, and just a hair behind the CG mark. This is with the upgraded elevator servos. I'm wondering about Reciever/satellite placement since the top deck is now pretty crowded. I might have it in the front tray, and extend the Sat out towards the nose.

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    • Just finish adding the final details to my MiG. Just a little bit of black paint and some extra led’s. Ready to add more flights tomorrow.
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      • Originally posted by janmb View Post


        Yeah, both ways are certainly doable, just a pain to plug the second one in close enough to the first one and then make sure to calibrate both before the first ESC goes into the first menu option.

        Some ESCs still perform calibration when pulling the throttle even if this also enters a sub menu, but some others don't. Don't know which category the ESCs in the MiG falls into. Just recall James trying to demonstrate this on the Bronco a while back, and did a perfect demonstration of too much gap leading to one ESC calibrating and the other not.

        I generally tend to sort stuff like this while the model is still on the build table, using separate power source as required, and with only one throttle connected at a time.
        The easiest way is to make a Y-lead from one battery (preferably small, like 3S/2000mah) with two connectors on it... Plug in the battery and calibrate both ESC:s at the same time. And by using a smaller battery you don't need to have the scary 6S/4Ah+ batteries on the workbench.

        I use a small battery on my 6S models for testing on the bench. With a long lead >30cm/12" it can lay on the bench no matter if the aircraft is upside down or not, thereby no need to tuck the battery in when testing landing gear and such.

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        • My calibration workflow for the Mig (and F14 before that) was to disconnect the BEC and power the Rx with a 4xAA caddy that i use for servo testing.

          Throttle up, plug a flight pack in to one ESC, calibrate, unplug the pack and repeat for the other.

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          • Originally posted by janmb View Post

            First of all, never mess with throttle trim on an electric setup. If your radio supports it, disable that trim entirely.
            I'm not so sure that this is an accurate statement. I'm no TX or ESC guru, but I've been using the throttle trim on electric planes for quite some time. I know the "conventional" thought is that throttle trim is only for gas/glow engines, however, Chris Hinson (owner of Extreme Flight RC) several years ago suggested that I increase the throttle trim on my electric 3D Extreme Flight planes to the point just before the prop starts to spin at the 0 position. He said that this will give much smoother and better low throttle characteristics than leaving it at where you program your ESC. If you've ever noticed, the low end of the throttle sometimes has a "dead zone" where the motor doesn't start spinning until the throttle is advance to 5-9%. Trimming it eliminates that dead zone. I use Castle ESC's in all my Extreme Flight 3D planes and always trim the throttle, but you need to remember to reduce it back to 0 when finished, before installing a new battery and starting again, to keep the 0-100% range effective.

            I adjust the throttle trim on every prop plane I have, especially the 8 warbirds I have that have a sound system in them. For those, the trim is set so the prop just barely starts to spin at the 0 point and the throttle cut switch is used to stop the spinning and also start and stop the sound system. By "tricking" the sound board, the sound starts as soon as the throttle cut switch is released (at which time the prop just barely starts turning-simulating a true engine start up) and never shuts off until the throttle cut switch is engaged, thus ensuring the sound system is always "on" until finishing taxiing after landing and "shutting down the engine". Without it, the sound system recycles whenever you reduce the throttle to 0, even while flying or taxiing, which kind of makes the sound system seem stupid.

            On all my EDF's I make sure the throttle is trimmed so the fans turn when going from the 0 position to the first notch of the advanced throttle. Some of my EDF's, even after programming the ESC correctly, don't start the fan until the 2nd click and this "extra dead zone" is annoying, at least for me.

            I'm not looking to start another war, just saying there are more ways than one to skin the cat and whatever you feel better with, use it. Since Chris suggested this, I feel I have a lot more throttle control at the lower end than before, but that's just IMO.
            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.

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            • I think you're just moving the deadzone with trim. If you have say 2% trim at zero throttle to give you immediate response then full throttle will be 102%, so you're hitting 100% before the stick gets to full deflection. To compensate for this you might recalibrate the ESC but presumably that reintroduces the deadzone back at the bottom.

              How noticeable that is in flight is debateable lol, and I have the same trick to get sound systems to commence their engine start as soon as you disengage the throttle cut.

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              • Another way to power up the other esc is a portable Bec .. I have a channel on my Tx & Rx dedicated for testing components like servos/Retracts ,etc .. Very handy especially for testing ABs out of the Box before installing onto the plane..
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                • Originally posted by Bushong572 View Post
                  I made 2 more flights today with a revised CG. I moved my RX and UBEC as far back as I could (beside the rear battery). My 2 RT 5500 mah are already as far back as I can get them. My new CG is 10mm behind the factory marks. The plane does fly better (you don't feel like you're having to hold the nose up all of the time). I now have 3mm of up trim instead of 5mm. I still think that is alot of trim, but I will probably leave it. I would have to add weight to the rear to move it back any further, which I might do eventually. The plane flies well and takes very little elevator to hold it inverted.

                  I'm curious about brake options. I run brakes on all of my EDFs and turbines (since I fly from a paved runway). The JPs in the stock wheel size are expensive and very heavy.
                  How about putting in some afterburners? Added weight in rear and special effects!
                  Fly low, fly fast, turn left

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                  • Or thrust vectoring...

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                    • I picked up a second JF/ HET/ Castle 8S set up. Considering using it here. Also considering adding TVs since I'll have the added power. Both will add significant weight and over all expense in one flying machine.

                      Another choice would be use one in the Gripen and also add TV.

                      Decisions decisions...

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                      • Where do these go?

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                        • Vertical stabs if you put the tiger decals on.

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                          • Originally posted by Evan D View Post
                            Vertical stabs if you put the tiger decals on.
                            Thanks. I looked at the close up of the vertical stab (last picture) in the product webpage and I can't see them. Maybe James didn't put them on?
                            At Motion RC we carry the largest selection of electric and gas powered radio control (RC) planes, boats, buggies, cars, helicopters, tanks, trucks, and much more. We also offer a huge selection of lipo batteries, chargers, ESCs, gas engines, motors, radios, and servos. Shop our lowest prices with free shipping.

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                            • Originally posted by Evan D View Post
                              I picked up a second JF/ HET/ Castle 8S set up. Considering using it here. Also considering adding TVs since I'll have the added power. Both will add significant weight and over all expense in one flying machine.

                              Another choice would be use one in the Gripen and also add TV.

                              Decisions decisions...
                              Interesting dilemma..Since the Gripen is still weeks away & if you have all the electronics ready to go you can install the JFs into the Mig29 & see if it’s worth the upgrade.. You’re probably worried once you go 8s you won’t go back to 6s

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                              • Originally posted by xviper View Post
                                Where do these go?

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                                • Originally posted by xviper View Post
                                  Where do these go?

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                                  Even closer. These decals are too dark...

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                                  • Originally posted by janmb View Post

                                    A: No, and explained to you earlier from both me and others (Kallend etc I believe), nor is that relevant what so ever in terms of discussing what boils down to basic physics. The debate on whether or not servos are fine has nothing what so ever to do with your (or anyone else's) experiences when flying the model. On the flipside, if I have received my own model already and put 100 flights on it, that would NOT have given me any more or any less basis for an opinion on this particular issue.

                                    B: See A

                                    C: About 300. See A for relevance.

                                    D: No, nor is that relevant, and nor did you.

                                    E: Yes, as I told you before, I have listened to every minute of Alpha's stream.


                                    Since I am insane, lets do a little follow up questionnaire shall we...


                                    A: Do you agree that we know for a fact that the servos fail when configured with the wrong geometry?

                                    Answer: of course, they like most others will fail when significantly installed outside of their design specs, which the manual clearly states on correct installation.

                                    B: Do you agree that the load difference the servo sees when comparing the third vs the second hole is approx 30%? (basic math, feel free to do your own measurements)
                                    A. No, it’s closer to 20% since we are rounding here...

                                    C: Do you understand the concept of Mean Time Between Failure?

                                    A: Part of testing real and model aircraft systems. Have about 5 times as much time flying real aircraft as models 14,000hrs+

                                    D: Do you understand the relation between marginal performance vs MTBF?

                                    A: Yes, I’ve test flown real and model aircraft.

                                    .
                                    300 flights on twin 80mm 6S birds, that’s great! Good size data set.

                                    How many of those are on full flying stab twin 80s?
                                    ie not the A-10 etc?

                                    Lets say the F-14 and Mig-29? Maybe others?
                                    I have somewhere north of 500 between 2 F-14s and now 50+ on the new Mig.

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                                    • Click image for larger version  Name:	B5A8F22E-A6A5-4D1E-B741-8BAC99569458.jpeg Views:	0 Size:	223.1 KB ID:	276539 Day one at the St George Electric Fun Fly complete!

                                      Beautiful weather and fantastic people with lots of flying.

                                      My Mig now has more than 50 flights on it, with stock 17g servos. I finally installed the Upgrade/replacement servos at the field today. No appreciable difference in how the jet flies on the upgrade/Replacement servos. They seem to move a little slower than the original 17g, and they have a gold head spline.


                                      Theres an INSANE amount of speculation on the forums about FREEWINGs decision to ship with the 17g, but the data set that they have gathered show FAR FEWER crashes on the 17g set up, than other legacy full stab models. (F-16, F-22, F-15, etc)

                                      The 3 aircraft you see here, and at least 3 more like them showing up today have north of 75 flights across 6 airframes on the stock/original 17g servos, all set up per the manual, and ALL with zero failures. Most of those flights are on my bird and I’ve pushed it HARD, with CG ranges well aft and forward of the marked CG, the model and servos have performed FLAWLESSLY.

                                      Total flights for all 6 is over 110, and all of us as OWNERs of the models love them. Huge congratulations to the design team.

                                      Look for a lot more pics and live FB videos from SEFF the next couple days.

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                                      • J

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                                        • Originally posted by HellHathNoFury View Post
                                          Another way to power up the other esc is a portable Bec .. I have a channel on my Tx & Rx dedicated for testing components like servos/Retracts ,etc .. Very handy especially for testing ABs out of the Box before installing onto the plane..
                                          Good idea! I’ll have to make one of those. Thanks for sharing.

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