JR G550T GYRO DRIFT
10-15-2003, 07:48 PM
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JR G550T GYRO DRIFT
[
] I am currently trying to set up the Heading Hold function on my JR G550T Gyro. I machanically adjusted the Heli in Rate Mode so there is no sub trim present but when I switch to Heading Hold( VIA the gear switch) the Heli turns to the right. If I dial 4 Clicks of left trim while in HH Mode, the Heli holds its position but is now out of trim for Rate Mode. The Radio is a JR 3810 PCM RX with digit servos. Can anyone help ?
] I am currently trying to set up the Heading Hold function on my JR G550T Gyro. I machanically adjusted the Heli in Rate Mode so there is no sub trim present but when I switch to Heading Hold( VIA the gear switch) the Heli turns to the right. If I dial 4 Clicks of left trim while in HH Mode, the Heli holds its position but is now out of trim for Rate Mode. The Radio is a JR 3810 PCM RX with digit servos. Can anyone help ?
10-15-2003, 09:47 PM
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RE: JR G550T GYRO DRIFT
Both JR gyros I've owned required some subtrim to minimize the drift in HH mode. I had to neutralize the drift in HH mode with subtrim and then trim the linkage in rate mode.
10-16-2003, 04:15 PM
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RE: JR G550T GYRO DRIFT
Thanks I will give that a try tonight. Doesn't the "Rudder Subtrim" still affect the normal trim when you switch back to rate mode ?
10-16-2003, 06:40 PM
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RE: JR G550T GYRO DRIFT
I suppose it would depend on how much you actually have to add but subtrim in rate mode is only a small fixed amount of servo angle, not a continuos heading change command. You should be able to trim it out with the linkage.
10-20-2003, 09:22 PM
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RE: JR G550T GYRO DRIFT
As Heading Hold is turned on by my Gear Switch, I added +8 "Gear to Rudder Mixing". Now when I switch to HH, the mixing value adds the required offset and the Heli holds its position !
10-21-2003, 12:45 PM
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RE: JR G550T GYRO DRIFT
I was asking myself exactly the same question last night and came up with the same solution! 
I also wonder, The manual tells to adjust travel while in rate mode, but is it normal that when I switch to HH mode, the travel seems to want to go farther?
I also wonder, The manual tells to adjust travel while in rate mode, but is it normal that when I switch to HH mode, the travel seems to want to go farther?
10-29-2003, 10:45 PM
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RE: JR G550T GYRO DRIFT
Since my original post I have experimented with the Gyro setup and found the fix for Drift in HH mode as follows.
1.Turn on your Gyro System and let it warm up for 5 min.
2. Remove the lid on the Gyro Amplifier.
3. While switching between Rate Mode & HH Mode adjust the Variable Resistor labeled RV2 until the is no drift when switched to HH.
4. As the amplifier Rate Mode neutral position driving the servo has now changed, mechanically re trim your heli in Rate Mode by flight testing and adjusting the length of the linkages.
5. Now when you switch to HH Mode in flight there should be no drift !
1.Turn on your Gyro System and let it warm up for 5 min.
2. Remove the lid on the Gyro Amplifier.
3. While switching between Rate Mode & HH Mode adjust the Variable Resistor labeled RV2 until the is no drift when switched to HH.
4. As the amplifier Rate Mode neutral position driving the servo has now changed, mechanically re trim your heli in Rate Mode by flight testing and adjusting the length of the linkages.
5. Now when you switch to HH Mode in flight there should be no drift !
