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Thunder Tiger GT5 FBL System Thunder Tiger GT5 Flybarless Electronics


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Old 05-21-2012, 09:34 PM   #1
Oilsands
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Default Heli wants to tilt when lifting off

I have an issue with my GT-5 and heli.
I had it flying a few weeks ago, but then decided to redo my linkages (move my ball in on the servo horns to give me 7 degree max for cyclic) and tweaked a couple settings due to the new location on the servo horns.
I then tried to fly and as soon as it got just got off the ground it nosed forward and struck the blades, got that repaired. Tried again and again it was wanting to tilt one way or another. Removed the blades (main and tail) and spooled it up and the swash stayed level. Reset the gyro and setup again, everything moving the way it should. Tuned the P and I settings to 40 for all, added expo to 45%, turning the Elevator and Aileron from 100 to 80 each, pitch at +-11 and cyclic at +-7. Tried it again today and still the same issue. HS at 1900 rpm on a Raptor 50v2 FBL.
Put the FB head back on and 401 gyro for now to get me flying as my other heli is waiting parts, few very well after that but would like to get this working with the FBL and GT-5.
Any ideas?
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Old 06-20-2012, 05:15 AM   #2
leex70
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Wel because it is tilting one way or the other you can rule out lots of mechanical problems.
How is the swash reacting on the bench. Sure all gyro compensation is ok?
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Old 06-25-2012, 12:39 AM   #3
guruduck
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I have tried different flybarless controllers and there is one brand, not GT5 that is very sensitivity to main blade imbalance and it will tilt to one side on spool up. But once it is in air, it behaves well.

I know GT5 is very forgiving in this respect, but it won't hurt to recheck on blade balance.

Hope this helps

Guruduck
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Old 06-26-2012, 01:30 AM   #4
Oilsands
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It was flying decent before I redid my linkages and tweaked the settings (had to change as I needed to have more servo travel now due to moving the ball links in on the servo horns). It seemed to spool up ok and the swash looks like it is staying level, that is until the heli gets light on the skids. I ended up damaging a set of blades when it tilted too far. I have not played around with this since changing it back to FB till I get my other heli in the air. Once I have that one flying, I may look at putting this back in and trying again. Thanks for the suggestions.
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Old 06-26-2012, 02:40 AM   #5
Kiwi-heli-nut
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Default um ...... might be barking up the wrong tree ...but

Hey there.

not sure of the age or condition .... .but the only time this has happened in my experience..... is when a swash bearing had come loose in its crimping and causing it to act erratically.

Caused very similar symptoms.

Cheers,
Westy
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Old 07-30-2012, 11:40 PM   #6
karlp
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I have the same issue and was wondering if you had gotten any further in resolving this. What I have found is that lowering swash P and I gains until the helicopter is genuinely unstable and then raising them again seems to do the trick. I have yet to test this theory 100% but in hindsight it seems to be what happened the last time I was out messing with the 450. I have not adjusted anything though, it just started happening.
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Old 08-08-2012, 09:11 AM   #7
XYZVector
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Level the swash most the time I find a tilting heli on takeoff is
A swash that is not level. When you tradition to flight if the swash is not
Level the heli will start off flying tilted once the gyro can controll the heli because
It's flying it corrects for the swash not being level automatically.
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Old 09-03-2012, 12:15 PM   #8
Nitros83
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Sub I got the same issue, first time trying the gt5, it's on a 450
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Old 10-23-2012, 10:07 AM   #9
karlp
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This is a "feature" of the GT5. It had me confused, then baffled, then angry and finally very, very happy. The problem has nothing to do with your mechanical or electronic setup but everything to do with having big brass nuts. The swash simply does not behave until you are airborne so just take off and trust the gyro to cope once you have lifted off. I also tried adjusting P / I values up and down and it does work but only because at 0 gain the swash kinda auto-levels (which makes a lot of sense if you think about it). Once I overcame the fully manual input lift-offs and got to fiddling with the gyro I not only changed my mind about 'wasting money on junk' but have since bought at second one for the 600. I have setup and fiddled with almost every 3-axis gyro on the market besides the Futaba 750 and the new 'baby' Skookum and this is far and away my favourite.... but only after much head scratching and a few choice words not appropriate for polite conversation. The value in not having to plug anything in at the field can not be overstated.
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