DX7 + GY401 strange rudder behaviour

[ignis]

Question 1:

I've just finished (I hope) setting up the gyro on my t-rex 450se v2. this is my first heli and my first gyro, so after everything was done I was somewhat surprised at the behaviour of the rudder servo. when I move the rudder stick on the control in one direction, the servo follows it, but then gets "stuck" there instead of moving back to center like it did before I plugged in the gyro.

my GYRO SENS menu settings are:

AUTO
Rate:
0: 72%
1: 72%

F.MODE
NORM: 0
STNT: 0

the question is: is this what is supposed to happen with a properly setup gyro, or did I mess up somewhere?


Question 2.

I've watched both Jermo's DX7 Setup Video (http://helifreaks.com/showthread.php?t=28681) and 401 gyro setup (http://video.helifreak.com/?subpath=finless/trex450&filename=gyro_setup.wmv) videos. combined together they have been nothing but confusing when it came to setting up the gyro.

first of all, my DX7 does not have a "HOLD: 0" line under F.MODE in the GYRO SENS menu. why is that and how will this affect me?

second, I'm now completely confused about the gain setting. Jermo says that 72% rate means 32% gain at the gyro and advises to keep it that way, but finless' video says that 60% gain or more is the advised setting.

that about sums it up my current problems. any help?

[TheBum]

Question 1:

I've just finished (I hope) setting up the gyro on my t-rex 450se v2. this is my first heli and my first gyro, so after everything was done I was somewhat surprised at the behaviour of the rudder servo. when I move the rudder stick on the control in one direction, the servo follows it, but then gets "stuck" there instead of moving back to center like it did before I plugged in the gyro.

my GYRO SENS menu settings are:

AUTO
Rate:
0: 72%
1: 72%

F.MODE
NORM: 0
STNT: 0

the question is: is this what is supposed to happen with a properly setup gyro, or did I mess up somewhere?
Is this on the bench or actually flying? It's normal for it to do that on the bench because the gyro expects a change in orientation in the direction of the rudder input, so it keeps the tail pitch kicked in somewhat if the tail is not obeying its command. When you're bench testing, the slider should only go to center automatically when the gyro is in rate mode .

Question 2.

I've watched both Jermo's DX7 Setup Video (http://helifreaks.com/showthread.php?t=28681) and 401 gyro setup (http://video.helifreak.com/?subpath=finless/trex450&filename=gyro_setup.wmv) videos. combined together they have been nothing but confusing when it came to setting up the gyro.

first of all, my DX7 does not have a "HOLD: 0" line under F.MODE in the GYRO SENS menu. why is that and how will this affect me?
It allows for a different gain or gyro mode when you flip the Throttle Hold switch. Since you have both of your gains/modes set the same, it won't make a difference.

second, I'm now completely confused about the gain setting. Jermo says that 72% rate means 32% gain at the gyro and advises to keep it that way, but finless' video says that 60% gain or more is the advised setting.

that about sums it up my current problems. any help?
It all depends on your setup. The values Jermo and Finless suggested were just starting points. You'll have to experiment with different gains until you can get the tail to hold steady without wagging. For instance, I had to switch to setting my GEAR channel to GEAR because I couldn't get enough gain in GYRO mode to stop my Diablo's tail from drifting. GYRO will only allow the equivalent GEAR channel endpoint to go to 100% and mine is looking to be steady at around 130%, although I'm still in the progress of calibrating the gain; I had a serious crash yesterday (stripped servo gears, bent boom) because I overcompensated when adjusting the gain and lost control of the heli; I'll have to make repairs before I can complete the job.

[ignis]

yes, that was on the bench. glad I have, after all the stress, done something right (if you can't do something smart, do something right, eh? :)).

you've covered the rest of my questions pretty thoroughly so I really have nothing to worry about at the moment. I'll start playing around with gain once I start flying so I'll put that particular problem on hold right now.

thanks again.