GY401 Setup Questions

[TurnerSM]

G'Day everyone,
I've got a TT Mini Titan that I am finishing the setup on, and have some questions regaeding the setup and operation of the GY401 gyro.
I've got the bird all together, and made good use of the videos produced by Finless (Thanks!), including the setup of the 401. The tail servo is a Futaba S9257.
The issue I've got is that when I give left or right rudder, the servo will track all the way to the limit, even if I return the stick to center.
For example, with all controls and the tail rotor hub at center (no motor connected), I nudge the stick left and then back to center. The servo will travel to the limit and stop. It does this in both directions.
I am in normal mode when I do this. If I go to Idle2 (I've got switch E setup as Finless describes in the 401 setup video), the 401 turns off and the servo behaves normally (is proportional to the stick).
Is this gain, or did I miss somethig in the setup? :confused:

Thank you in advnace for any help or guidance!

[Jermo]

that's normal when the gyro is in heading hold mode.

[BarracudaHockey]

In heading hold the gyro tells the tail to move. If it doesnt move it holds the command until it does. On the bench the tail isnt going to move.

In the air it works fine.

[TurnerSM]

Cool! Thank you!

[Tim Smith]

Can any one tell me why I can't get this ticking movment outta my Tail .Its not Wagging ,and its not hunting It does this thing like a tic toc back and forth and it is very timed like one second like a clock .It goes Tic Toc it only moves about an inch or tow very steady very much like its on a timer going Tic Toc Tic Toc...........I adjust the Gyro sensitivity up and down one percent at a time but it wont stop.......it does it on both heli one with a gy401 futaba and JR DS3400 servo and the other with a JRG7703D and DS 3400 servo set up both heli's are Trex 450 se's

[DavidH]

That is fairly normal on the electronic gyros. The servo is constantly twitching even when the heli is sitting still on the bench.

David

[forjer]

Not meaning to hijack your thread here...I think it relates.

Two questions.

1. In normal mode after I adjust the servo travel using the gyro's limit pot, the servo reaches its "new" endpoint at about 60% of the rudder stick's available travel. Do I then go into the radio and adjust the rudder channel's endpoints down to achieve full servo travel with full stick travel?

2. After doing #1 and switching back to HH mode, the rudder servo once again reaches its endpoint well before the stick reaches full. Is this normal gyro operation in HH mode with the heli sitting on the bench?

[bigdog 714]

How it was told to me is the rudder travel should be at 100% for set up and the ball link on the servo arm should be positioned so that full motion is used with the tail pitch slider coming as close to, but not hitting the end points. After the mechanical settings have been made to hold the nose steady during hover the tail rotor is usualy around 8deg. from center, so when moving nose right the tail slider will hit, and nose left it will fall short, now you adjust the end points, basically your taking the 8deg. from the long side and adding them to the short side.

[forjer]

Thanks bigdog...that all makes sense. Anyone else have anything to add in relation to my questions?

[jlr]

Do not decrease the endpoints. In normal mode, if the servo reaches the limit of travel at about 60% of stick movement, I think you'll find the yaw response about right. If you reduce the endpoints in the TX to match the limits set in the gyro, you'll find that the yaw rates at full stick are very slow.

In HH mode, it's hard to say what is "normal" because the even small inputs can get the servo to move to its limit over time.

--Jeff

[forjer]

Thanks Jeff, I'll try resetting my rudder endpoints to 100%...after I rebuild. For some reason I need some new blades...and main rotor shaft, tail boom, tail rotor shaft...at the least.

[forjer]

I reset my endpoints to 100%...that sure does make her spin fast!:thumbup:

[Roadbiker3]

You guys have any idea why my 401 came out of HH mode while flying. I plugged the battery in and the light was solid, after a few minutes of flying the tail would not hold so I brought it down and the light was now blinking? any ideas.

Thanks,
Jim

[forjer]

Are you sure it switched and you weren't just giving rudder input?

Otherwise, I suppose the switch may not have been all the way into HH and the vibration caused the switch to fall to the rate side. It's a small switch so you really need to look to see that it is fully switched one way or the other.

[Skiddz]

What switch? On the gyro? The 401 only has 2 switches.. One to reverse it, one to set the servo output to digital. There's a gain and delay pot as well. Switches on the TX wouldn't "pop" out of position due to vibration unless you REALLY got the shakes..

[forjer]

My bad...I was thinking of the reverse switch. Is it still happening?