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Tail Twitch

Old 07-31-2010, 06:37 AM
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Default Tail Twitch

Had a crash with the T600. It rolled over and buried its blades into the ground.The rotor head actualy survived with exception of flybar, main rotor gear (stripped), frame flooring and skids. The rotor and feathering shafts did NOT bend. Isetup the rebuild. Upgraded blades from fiber-glass to Curtis Youngblood 600MM RADIX blades. In hover the chopper now has an occassional tail twitch.

Adjusting the rudder EXPONENTIALup 5%from 20% to 25% helped reduce the tail twitich frequency but it didn't eliminate it completely as Ihad accomplished before the crash. I am hesitent to take it up higher though as 20% rudder expo seems to be the most common setting value.....but then again there are some folks out there that are firm believers in taking the rubber expo up to 80%.

Also in myPRE-CRASH setup Ihad to adjust down the GYROGAIN from70% to 60% as in the flights Ihave been doing prior to the crash day had the tail aggressively twitchingat 70%...butwent completely away at 60%.Ileft that setting in the POST-CRASH setup. SHould Iadjust the GYROgain instead of the EXPO?

Is it possible the change to a more aggressive3D carbon-fiberbladeisnow somehow impacting the tail rotorfunctionality via theGYRO? If so which wayshould GYROGAIN be adjusted...back to 70% or lower than the current 60%?

Any advise would be greatly appreciated. Thanks!


Old 08-01-2010, 10:56 PM
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Default RE: Tail Twitch



uhh.....er.....well....thanks for the help folks.....</p>
Old 08-02-2010, 02:16 AM
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Default RE: Tail Twitch

its kinda hard to understand what do you mean by tail twitching? is it like tail wag? is this a nitro or Electric 600?
Old 08-02-2010, 11:36 PM
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Default RE: Tail Twitch

Frequent and fast shorttail wag movements. As if GYROis searching toorient thetail to proper position. The copter is electric.
Old 08-03-2010, 09:26 PM
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Default RE: Tail Twitch

if it's belt drive u might b missing a few teeth on the belt, just a guess
Old 08-04-2010, 03:41 AM
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Default RE: Tail Twitch

check the electronics.. it might be skipping.. sometime the power on the motor is not smooth and clean.. it somewhat jitters.. if this happen the tail gets affected as if the gyro was at fault
Old 08-07-2010, 08:48 AM
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Default RE: Tail Twitch


ORIGINAL: soneebee

check the electronics.. it might be skipping.. sometime the power on the motor is not smooth and clean.. it somewhat jitters.. if this happen the tail gets affected as if the gyro was at fault
I think Imight have narrowed it down as to what the root cause is that is causing the tail twitch. Ihavethree 22.2 5000mAh 6SThunder Power batteries Iuse for flying the T600. Two of them have a single weak cell in them andone batteryis completely OK,

When Iuse either of the two having the weak cell, the copter tail will twitch. When Iuse the one completey OK battery the tail doesn't twitch. So Iam concluding from this consistent repeatable pattern that it has to be the two batteries with the single weak cells in each one that is causing the issue. Iassume then the electrical current continuity is being interrupted and the tail twitch is the indicator of when that momentary continuity disruption is occurring. This certainly speaks to what you were suggesting as a place to start looking.

Thanks!
Old 08-08-2010, 05:22 AM
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Default RE: Tail Twitch

if its a single cell that is at fault... then the ESC is cutting off... this causes the twitching....
Old 09-26-2010, 12:09 PM
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Default RE: Tail Twitch

Just wanted to add that I had the same problem with my Trex 500 when running 2 3S 2200.After switching to 6S, the tail twiitch went away.

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