Gy401

[MartinH]

Tempted to get the gp750 gyro if I cant set the limit correct on the 401, basically my servo arm inst 90 deg to the servo (when it is the tail rotor isnt center and theres little travel left for it to go left (looking from the back of the heli)).
So Following finless bob I center the rear rudder regardless of the tail servo (it isnt miles away from 90 just not 90 lol) and set the gyro for HH, the weird thing is is that I can get perfect limit when pushing the tail rotor to the right so its closet to the blades but It binds and doesnt stop when moving towards the boom.
I have the 4 arm type servo arm:
Fast Lad Performance
that isnt the exact one but just to show you,
Now can anyone give advice on how to set the limit please .
The servo rod is about 10mm from the servo center just like the manual, im tempted tomorow to move it to the next hole along.

Ive spent almost 2 days trying to figure it and after endless research and watching legend bobs vid on the rudder that ive givern in and asked here .

[Nick B]

Try swiveling the servo arm to a differnt arm,most are not symetrical

EDIT...those ones in the link are /

[MartinH]

Try swiveling the servo arm to a differnt arm,most are not symetrical

Im going to try that again, the only slight thought I have is that theres the usual mark where you get the nut rubbing etc so I could tell that was the correct arm and hole but i'll deffiantly try that tomorow.

[Nick B]

Get a disc type horn on there,plenty of options then

[MartinH]

Very true, could order when I get my charger etc.

[Mart61]

In order to get it not to bind, the arm on the servo has to be bang on centre, as does the tail pitch slider need to be plum centre of the tail rotor shaft.

The 401 only allows limits to be set as a percentage of the total range of movement. Therefore any alteration of the limit pot limits the range of movement to both left and right of centre equally.

It took me a couple of attempts to get it bang on but my 450 tail is working just fine with my 401 - full range of movement with no binding either end.

[antsis]

Tempted to get the gp750 gyro if I cant set the limit correct on the 401, basically my servo arm inst 90 deg to the servo (when it is the tail rotor isnt center and theres little travel left for it to go left (looking from the back of the heli)).

Buying a different gyro will not necessarily resolve this as you will still need to set the limits. It sounds like your problem is in the mechanical setup. Have you tried adjusting the rudder pushrod to get the tail blades in the centre?

Here's a link to the Futaba site and their setup guide.

Team Futaba Tip #2

There are a couple of things you need to look at as well. One is the distance of the ball link to the centre of the rudder servo. The norm is approx 13mm. Moving the ball closer to the centre allows you to increase the limit and get more movement out of the servo.

The other thing you need to bear in mind is that you do not necessarily need to have full deflection on left rudder as the model will naturally rotate this way due to torque. You will always need more right rudder to counter the torque effect.

[Mart61]

During build/set-up stage, I found that an alternative to tinkering with the pushrod length is just to move the servo up and down the tail boom a fraction, after the servo is at 90, to get the slider bang on centre.

[MartinH]

In order to get it not to bind, the arm on the servo has to be bang on centre, as does the tail pitch slider need to be plum centre of the tail rotor shaft.

The 401 only allows limits to be set as a percentage of the total range of movement. Therefore any alteration of the limit pot limits the range of movement to both left and right of centre equally.
It took me a couple of attempts to get it bang on but my 450 tail is working just fine with my 401 - full range of movement with no binding either end.

Thats the problem mate, with the servo arm 90 the tail rod just doesnt seem to be long enough to reach the ball link on the tail to keep it center, if I did then the links which slide to give the blade angles goes all the way to the left (looking from the back on the heli) that means the'll be no travel left.

EDIT: infact I might have just come up with the problem.

Buying a different gyro will not necessarily resolve this as you will still need to set the limits. It sounds like your problem is in the mechanical setup. Have you tried adjusting the rudder pushrod to get the tail blades in the centre?

Here's a link to the Futaba site and their setup guide.

Team Futaba Tip #2

There are a couple of things you need to look at as well. One is the distance of the ball link to the centre of the rudder servo. The norm is approx 13mm. Moving the ball closer to the centre allows you to increase the limit and get more movement out of the servo.

The other thing you need to bear in mind is that you do not necessarily need to have full deflection on left rudder as the model will naturally rotate this way due to torque. You will always need more right rudder to counter the torque effect.

My idea of buying the gp750 is that its, as far as I can see and tell from bobs vids, easier to set up, or am I wrong :/.

During build/set-up stage, I found that an alternative to tinkering with the pushrod length is just to move the servo up and down the tail boom a fraction, after the servo is at 90, to get the slider bang on centre.

I have the pro model, the rear servo is mounted within the heli, otherwise id deff do that .

Thanks for the input guys, Im going to get it done tonight, bearing in mind antsis advice that the heli doesnt need as much travel to the left.

[Mart61]

I have the pro model, the rear servo is mounted within the heli, otherwise id deff do that .

Ah - might be a problem then.

[MartinH]

Ah - might be a problem then.

I'll get it sorted buddy dont you worry about that.

[Mart61]

If you weren't all the way down the M4, I'd sort it for you.

[MartinH]

And Id love you forever, ill get it done tonight I reckon, just something else to learn to do .

[MartinH]

Got it sorted, for some reason in the back of my mind I was saying to myself check the tailboom check the tailboom, finally did and found it wasnt plugged in all the way :/, so span the main head while gently pushing on the tail and it went it and now the servo lines up 90 and all I need to do now is screw the joints on the line boom and done , thanks for the suggestions everyone.

Been swinging the tail around and no binding, slitch hitch is that the gyro is on about the 70% mark, I read some where that if its below 80% then move the ball towards the center of the servo one hole but I cant do that so i'll just leave.