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How to configure gyro / tail servo

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How to configure gyro / tail servo

Old 06-04-2010, 03:23 AM
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Default How to configure gyro / tail servo

Hi all,
first up, this forum software sucks, it lost my first (very long message)

Anyway:Ijust built a trex 450 clone, and am having tail problems.
As soon as i take off a little bit, it starts rotating. The head lock light on the gyro is on. So i'm confused.
Are there good instructions somewhere for how to set it all up? I watched the video series by martysrc.com and it's awesome but to me it seemed to gloss over the tail setup.

THANKSSOMUCHYOUGUYSAREAWESOME!
Old 06-04-2010, 06:35 AM
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Default RE: How to configure gyro / tail servo

1st ) What kind of gyro is it ?. Each one sets up a little differant, without specific information it sounds like either your rudder channel is reveresed in your radio or depending on your location of the gyro on the heli, the gyro direction itself might need to be reversed
2nd) If you have not as of yet checked out Helifreak.com go there, they have instructional videos for almost all gyro setups, as well as build and other help videos & forums, and/or drop me an e-mail & I can probably help you out.
Jim R
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Old 06-04-2010, 10:44 AM
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Default RE: How to configure gyro / tail servo

Definitely need to know Gyro type.

In general, ensure that no trim or sub-trim are set for Rudder. Center Servo and ensure that the tail slider is centered (adjust tail servo link or move servo on boom). On your transmitter, set gain to roughly 70% to start. Ensure proper servo direction by moving nose of the heli and check direction (I normally spool up a bit without main blades to check (wind from the tail to compensate nose direction).
Old 06-04-2010, 09:22 PM
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Default RE: How to configure gyro / tail servo

Hi,
The gyro is a<font class="Apple-style-span" face="arial, sans-serif" size="3"><span class="Apple-style-span" style="border-collapse: collapse; font-size: 13px;">n Eskyek2-0704b
</span></font>It is correctly mounted, as in the right direction i can tell by looking at which way it moves the tail slider when i jiggle the rear.
It just doesn't seem to have any great effect when i actually take off. I mean, it's not like the heli goes into a rapid spin, but it certainly doesn't hold it's heading.
Old 06-05-2010, 02:55 AM
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Default RE: How to configure gyro / tail servo

According to the manual (found here http://www.helifreak.com/attachment....p;d=1234893085), there is a delay pod that may require adjustment. On the ++ side, it will control the HH mode. You don't need that if you have the gain lead connected to your receiver/transmitter. You can adjust HH from the transmitter.

Also, it seems that gyro is made for the Belt CP heli, so might not be a good choice for a 450. Note that the gyro doesn't have a Digital switch, so you won't get any advantage on that type of servo to hold your tail better (will work with both Analog and Digital).
Old 06-05-2010, 05:33 AM
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Default RE: How to configure gyro / tail servo

As far as i know, the Belt CP (which this gyro is from) is a 90% clone of the trex 450, so i would have thought it'd do the job just fine...
I think basically i just need a step-by-step instructions on how to set it all up, i'm a beginner and my mates fly planes not heli's so they're not much help
Any such instructions exist anywhere?
Old 06-09-2010, 04:43 PM
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Default RE: How to configure gyro / tail servo

Better gyros like the futaba GY401 will calibrate center stick so you just leave the trim zeroed for those gyros. Cheap gyros like esky don't have that feature and you need to adjust the trim to keep it from slowly turning one way or the other in HH mode. It may also vary with temperature.

If the tail is stable (not randomly moving around or spinning wildly) but moving steadily in one direction, that may be your issue.

Getting HH to hold isn't terribly difficult as long as your tail has full range of movement without binding (limit adjustment on gyro and position of tail servo) and the head speed is high enough.
Old 06-09-2010, 05:25 PM
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Default RE: How to configure gyro / tail servo

Thanks gnd2,
So from what you're saying, my gyro thinks that i'm wanting it to go left or right a little bit, hence the drift.
How to adjust to fix this?
Do i go into the Transmitter program and adjust the subtrim so that when i release the stick, that channel is at absolute zero?
Thanks for the help so far.
Old 06-10-2010, 06:27 PM
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Default RE: How to configure gyro / tail servo

Yes, the gyro "thinks" you're telling it to turn. Adjust the trim so that the heli doesn't yaw in HH mode.
Old 06-12-2010, 05:02 AM
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Default RE: How to configure gyro / tail servo

I didn't think that the gyro would allow any yaw in HH mode, because the slightest i move the stick left or right it goes off HH mode, but you may be right. Not sure how to adjust it to compensate though.

Although someone mentioned head speed! It got me thinking, my head speed wasn't too high because of the way i adjusted the swash plate servos. So i adjusted them down to normal and it goes pretty great now! Just a slight drift in the HH mode but it's tolerable (however i'd LOVE to know how to fix it).

One other thing, how do i reset the gyro's HH orientation without unplugging / replugging the lipo? Eg if i pick up the heli and move to another spot.<br type="_moz" />
Old 06-12-2010, 10:50 AM
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Default RE: How to configure gyro / tail servo

That should be no problem, as the main motor spools up you might want to touch the rudder stick a bit, and the gyro will sense a change of direction and will then correct. Until it lifts off the ground and the tail goes to one side, the gyro still thinks it is holding the tail steady. On a smooth surface, it is easier to do and a rough surface. I have also heard that for some gyros, you can 'shake' the tail right to left and back about 3 times, and it will recenter. That doesn't work for my on my various setups. Sometimes, with my JR7703D, I have to unplug and reconnect the battery to get proper tail centering.
Old 06-14-2010, 01:39 PM
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Default RE: How to configure gyro / tail servo

ORIGINAL: CrackerboxSydney

I didn't think that the gyro would allow any yaw in HH mode, because the slightest i move the stick left or right it goes off HH mode, but you may be right. Not sure how to adjust it to compensate though.
Not sure what you're trying to say here. But if you're trim is off from what the gyro expects, the gyro thinks you're telling it to turn so it turns. You fix this by simply adjusting the trim so it doesn't turn.

Although someone mentioned head speed! It got me thinking, my head speed wasn't too high because of the way i adjusted the swash plate servos. So i adjusted them down to normal and it goes pretty great now! Just a slight drift in the HH mode but it's tolerable (however i'd LOVE to know how to fix it).
I mentioned head speed. The tail rotor speed is proportional to the head speed. If you don't have enough head speed, you get a lot of torque from the increased blade pitch needed for lift and you don't have enough thrust from the tail to counter because it's going too slow. This could be the case if the heli is rotating counter-clockwise (looking down from the top). Although, if you're able to counter it with the rudder stick that may not be the case. On a 450 heli, your head speed should be around 2200-3000 rpm (a tachometer is a good investment if you don't have one).

One other thing, how do i reset the gyro's HH orientation without unplugging / replugging the lipo? Eg if i pick up the heli and move to another spot.<br type=''_moz'' />
Momentarily switch to rate mode then back to HH mode after you've set the heli down and are ready to take off. This will reestablish your current heading as the one the gyro is trying to maintain.

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