450 Tail Breaks loose

Lee

Lee

Well-Known Member
If your servo arm has been centred with the rudder sub trim at 0. all linkages set to put the tail pitch slider in the middle of the tail shaft, gyro in head hold, then the next thing is to adjust for "tail creep"
Does the tail move slowly over to the one side on its own once you have give a rudder input?
Go into you sub trim for rudder and add opposite trim, checking all the time by moving the rudder stick.
Eventually you will get to a trim point that the rudder will now stop creeping to one side. Give it too much trim and it will start to creep the other way.
Try this and let me know if it helped.
 
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billryalls

Member
Ok I'm back to this issue (I think). ;). I just reprogrammed and re-centered my servos into my dx9. All is well except the jerking of the rudder at hover. What the video shows is with gyro at 65. When changed to 85 it looks exactly the same. ??
[video=youtube_share;tIO9cY3zXMM]http://youtu.be/tIO9cY3zXMM[/video]

after viewing this I can't really see the twitching but it's a quite rapid left to right bouncing
 
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pvolcko

Well-Known Member
First, make sure nothing is mechanically sticking in the tail or control rod movement.

If gain adjustments aren't making a difference, and there is no sticking in the tail control movement, then you probably need to adjust the tail control end to get the length more correct to hold the tail steady while in rate mode. If it is significantly off, on some gyros, it will cause it to have trouble holding steady in heading hold mode.

To do that: Take off with it in rate mode instead of heading hold mode (use a negative gain setting in your gyro TX setting). It should be able to hold the tail in place fairly well wihtout yawing around if you have rudder at center stick. Be careful. If it is off a lot the tail will want to whip around at a fairly good clip, so spool up slowly and keep your rudder stick input smooth and constant to counter any yaw that occurs. If it wants to go in a certain direction, land it (or if it is whipping good on the ground, don't even take off), spool it down, center the rudder stick (this will recenter the tail servo), and power it down. Look at the tail blades then determine which way you need them to move to counter the direction it tended to spin in. Then adjust the ends on the tail control rod so the tail blades move that direction a bit (amount will vary by how fast it was yawing, more change if you had to hold more rudder stick, less for only a small amount of rudder stick). Rinse, repeat until you can get it into a stable hover with a minimum of rudder stick input to keep the tail in place.

Once you've done that, then go in, redo your tail setup on the gyro and try heading hold mode again. This should give you a good place to make heading hold gain adjustments from.
 
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billryalls

Member
My trex 450 3gx is doing great now BUT i now have an HK issue. My hk 450 is flying super stable and great except that if i give quick hard throttle my tail does a quick 180 before i have to bring it back. Is this a servo or gyro issue. Im using a good gyro (quark spartan) and the tail servo is a Savox 0262MG ?? OH! AND even though it flies stable it definitely leans left!? HOW can it be leaning left and not GO left??
 
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orbi

Member
billryalls said:
My trex 450 3gx is doing great now BUT i now have an HK issue. My hk 450 is flying super stable and great except that if i give quick hard throttle my tail does a quick 180 before i have to bring it back. Is this a servo or gyro issue. Im using a good gyro (quark spartan) and the tail servo is a Savox 0262MG ?? OH! AND even though it flies stable it definitely leans left!? HOW can it be leaning left and not GO left??
Click to expand...


hmmm sounds like a problem I had a long time ago.....my belt was slipping to the rear gearing on my sport, it was hovering great but when pressure was applied it was failing / slipping . Grab the tail rotars and turn the main ones to check for slippage. I had a heli that leant left but stayed straight in flight. Its a frame thing. try a Futaba s9257 for a tail servo you wont have any probs then. I got a second hand one( £28) GDP and re geared it, theyre virtually indestructible. I bought cheap and cheerful HK gears for pennies, had them in now for around 9 months, if i have a crash the servo fails at its weakest point .... at those cheap gears ! simple. good luck pal

- - - Updated - - -

Hows this for stable, I was hovering in dead calm zero wind the other evening, I managed a full 8 seconds with BOTH hands free before I had to adjust the set. I wonder what the record is ????
 
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