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Old Aug 08, 2012, 12:33 PM
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Stability issue

In my airplane(s) silly! Nah, couple weeks ago me and #1 Son bought a couple 750mm Airfield/FMS P47 Thunderbolts, he got the Silver one, I got the Green one. His is his "goal-plane", i.e., when he can put a few batteries through his Nine Eagles 400mm Spitfire, and ample time on our flight sim (Clearview), he'd be ready to fly his new plane. Well, the better part of a month has passed, and his new plane is still sitting on his shelf, collecting dust, because we tried to fly my green one, and she won't fly no matter WHAT you do. In fact, she crashes better than anything! Nitroplanes tried to convince me that it was pilot error (putting the thing up in the FIRST place was my error), and all the issues the plane has were "normal". A bowed main wing is not normal. ANYWAY, had to order a kit because Nitroplanes didn't have a mainwing in stock (broke the main wing twice), so did that, took all the innards from the green plane, and transferred them to the silver kit. Then I saw a thread at another forum about gyro stabilization for airplanes, and along comes Mike from out on the Left Coast with some head-lock gyros for sale. SOLD!! So when they arrive toward the end of the week, we're gonna put them in both parkflyers and the bigger 1400mm Jug I have, because the videos I've watched regarding these planes, I've noticed the kinda pull left at take-off, and it's my hope these gyros will cure that problem, so I can concentrate more on flying than fighting, we shall see. More to come...

Here's the "more" I promised. Swapped out the 6 Ch. TX/RX that came stock with my FMS 1400MM P47 for the 4 Ch. that was stock in the 750MM, and hooked up a Detrum GY48V Gyro for ailerons, and the leftward roll has been eliminated, the plane is so manageable now, I daresay it flies like a trainer...albeit a very FAST trainer. That aside, I noticed this morning when we flew it that there's a degree of flex in the main wing during a full throttle turn...there was a point where I thought the wing would break, but it didn't. I'm thinking in the event of a crash I may spar the wing with C.F., or fiberglass...ANYTHING to toughen it up a little. Anyway, We're bringing my Daughter with her camera to shoot some video of this rather awesome plane in action, so, stay tuned...

Of course, waking up a 15 year old DAUGHTER at 04:00 is always a challenge, hang in there for the video...
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Old Aug 08, 2012, 01:34 PM
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Canada, ON, London
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Hey there... I have a P51d from NitroPlanes (Dynam model) that was very tail heavy. Not sure if your P47 has the same issue, but make sure you err on the side of nose-heaviness.

Also, the veering off to the left bit is likely a torque issue - especially with a 3 or 4 blade prop. If you're cranking it up at full throttle on takeoff this will really have an impact.... 1/2 to 3/4 throttle might be worth a try.

The gyro will be nice, but I suspect if you've flown lots before and can't get the thing to fly without the gyro it might just be a dud . I hope not and I hope the gyro makes it a more fun flyer for you.

Anyway... just got curious as to whether you tried the above two things (nose weight & less throttle on takeoff)? Also... for the torque issue, one can change to a two blade prop... more efficient and less torqueyness (I know, it's not a word ;-)).

Cheers,
J
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Old Aug 10, 2012, 04:50 PM
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Yup did both things, and it was indeed a dud. The mainwing had such an exaggerated bow to it that N.P's Tech Support said was supposed to be like that, and I had seen pictures of the green plane, and it did have a slight upward bow, not dihedral, but a bow to it. I tried 2 oz. nose weight, per Tony's suggestion, no go. The plane got so banged up after 3 attempts to get it to fly, I just went ahead, and got the kit in silver, and just swapped out everything to the kit. Due to the fiasco with the green plane, I haven't put the silver one up yet...don't know if it's the 'ol "fear factor" or not, but have yet to fly it. Me and Sonny Boy (my Son) take the other planes we have, along with 2 helicopters, and fly all those with no issues at all. One is a Flyzone 3 channel Albatros, and the other 2 are Nine eagles 400mm Spitfire and P47, 2 of the smoothest planes I've ever flown, put all 6 LiPos through the 2 warbirds routinely, and I really need to get more batteries for the Albatros...that plane's just too much fun to only put one battery through. But project gyro is on hold, as the stock setup I have won't allow their use, as they have remote gain, which my RTF radios won't accomodate. No sweat, was gonna replace the stock radios with one for all the big planes, and perhaps a 2.4GHz conversion for the Double Horse (9104), because that heli is also big fun to fly, I'm just a little in the dark as to why it's operating frequency is in the middle of the C.B. Radio Band?? At least this one is (27.145MHz...Channel 15A on the C.B.), and yeah, LEGALLY you're not supposed to talk on that frequency, but people do routinely, and if anyone's within line-of-sight of your flying area, and they start talking, it's GONNA mess with that heli. Guaranteed. Hence the swap to 2.4, but that's down the road. But I think I'm gonna "grow-a-pair", and fly this thing hopefully tomorrow, cuz this one's wing is normal, so we'll see how it goes, but if it's anything like the green one, that plane had a real bad torque-roll, but again, we shall see...
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Old Sep 04, 2012, 09:41 AM
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Here's some footage of the FMS 750MM P47 in flight, and I gotta tell ya, this plane looks DAMNED nice in the air...
FMS 750MM P47 Flight (6 min 11 sec)

Nothing but good things to say about this plane now that it has a little help from the gyro...completely different airplane now!
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Old Oct 14, 2012, 02:20 AM
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Not sure what you think the gyro does, but on a calm day, as in the video, they do nothing at all.
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Old Jan 08, 2014, 08:53 PM
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I would have to beg to differ Gerry. The gyro on ailerons correct the leftward roll from the motor's torque. When you power up the plane, and keep it level, the Detrum will maintain that attitude, and any deviation from level will cause the gyro to correct to level. Were I to power up the plane, say, with a rightward tilt, the gyro would try to maintain that tilt. It's not what I THINK it does, it's what I know. Without the gyro installed, this plane, and really any other would roll left due to torque roll. Works for my plane(s) every. single. time. They work SO well, I no longer have the Detrum(s) in my planes, but have switched to the Orange 3 Axis Stabilizer, and the Orange RX3S DSM2 , and once airborne, can turn the gyro off from the radio, and only use it for take-offs/landings. They've paid for themselves MANY times over...more to come...
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