The latest Esky helicopters (such as the Belt CP and the Honey Bee Kings) are now being supplied with the EK2 0704B gyro fitted, that provides both RATE and HEADING HOLD features, whereas the older Esky gyros only provided RATE mode.

Now it seems that setting up gyros is seen by many to be a bit of a black art, and rightly so, as it seems that every gyro has to be setup in a different way, and even mounted in different orientations.

As the Esky EK2 0704B gyro is one of the most used gyros by "newer" pilots due to it being fitted to the types of helicopters that many "newbie" pilots use to learn to fly helicopters, I felt it really was time to spell out exactly how to set this gyro up, as it is certainly somewhat less than obvious to most people.

Firstly, this particular gyro should be mounted horizontally, as shown in the image above.  The typical position is on top of the boom clamp at the rear of the frame, immediately behind the main shaft.

You will see that the gyro has a connecting socket on it below the main connecting wire that goes to the receiver, which is where the servo connects to the gyro.

The main connecting wire is a little different to most, in that it actually has FOUR WIRES instead of the usual three wires.  The reason for this is very simple, as you will see if you look at the other end of the lead, where you will find TWO SEPARATE connecters to go into the RX.  However, one connector only has a SINGLE YELLOW wire in it.

It is this yellow wire connection that lets you switch the gyro between RATE and HH mode using the switch on the front of the Esky TX, and also to set the gain on the gyro using the knob on the top right of the 2.4 Ghz TX's. (NOT on 35MHz TX's) 

You must ensure that the single YELLOW WIRE connects in the 
same position as the white wire on all other connections.

Now you will almost certainly assume that BOTH of these wires need to be plugged in before trying to setup the gyro.  SURPRISINGLY YOU WILL BE TOTALLY WRONG

In fact it is ABSOLUTELY ESSENTIAL to REMOVE the YELLOW wire 
from the receiver BEFORE trying to set up the tail.

The reason for this is that if the yellow wire is left connected, it will allow the gyro to be switched, but it also blocks you from changing the "gain" on the gyro itself, which you are going to want to do a bit later on.

NB - Almost all gyros need to be setup in RATE MODE, not in HEADING HOLD, and disconnecting the yellow wire forces this gyro into RATE mode.

A short diversion here may be useful :

Rate mode means that the gyro simply "damps" the amount of swing the tail has :
IT DOES NOT keep the nose pointing in the same direction. 

However, when in Heading Hold (also known as HH or AVCS) 
IT DOES TRY TO KEEP THE NOSE POINTING IN THE SAME DIRECTION, (once setup correctly).

A quick way to tell what mode any gyro is in when it is all connected up is arm the helicopter (DISCONNECT the motor leads if necessary for safety) and then swing the tail around in both directions.

If the gyro is in RATE mode, the servo arm will always try to return the centre position

If the gyro is in HH mode, the servo arm will NOT try to return the centre position.

The same rules applies if you move the rudder stick fully left and right.

End of diversion (suggested by senoj_nai - thanks for that !)

So perhaps before we start getting into it all, it would be helpful if I try to describe exactly what we are trying to achieve ?

The first thing you need to understand is that the tail rotor blades cannot be set at a central (no pitch) position when the rudder lever is centred, for they need to be applying some force to counteract the rotation of the head when in the neutral position. 

As you can see from the images below, your tail blades will look "something" like this in terms of the angle of the tail blades, and you can also see that the pitch control slider is no longer centred on the shaft, it is offset inwards toward the boom.

This is what we are trying to achieve in the first stage of the tail setup, before we have ANY INPUT FROM THE GYRO WHATSOEVER...

However, we also need to ensure that once we achieve this, the servo horn on our tail servo must STILL BE PERPENDICULAR to the servo.  

If you have not done the full mechanical setup before :-

CLICK HERE to check out my detailed tutorial on the basic mechanical setup 
which you must do FIRST OF ALL

OK then, let's go ahead and do it ... ?

Although we do not need it yet, the first thing I like to do is to turn the gain on the gyro right down as far as it will go so that it does not effect our mechanical setup. You need to do this on the TX itself if you have the Esky 2.4GHz TX, so turn the knob on the top right fully anticlockwise to set the gain to it's minimum setting.

Also check the gyro and set the LIMIT to maximum, and the DELAY to minimum. We will re-adjust these later.

The second thing is to disconnect the single yellow wire from the receiver. This will also DISABLE the gyro switch from having any effect, and place the gyro in RATE MODE

WARNING - YOU ARE GOING TO HAVE THE ROTOR BLADES SPINNING QUITE FAST
SO PLEASE ENSURE THAT YOU STAY AS FAR AWAY AS POSSIBLE 
FROM THE HELICOPTER AND ALWAYS WEAR SAFETY GLASSES 

Make sure that the helicopter is securely tied down to the turntable, and that the turntable cannot move, apart from going around of course.  You will be surprised at how much lift, and vibration the helicopter can and indeed will generate while you are doing this.

Now to set up the tail, put the helicopter on a turntable (if you have one), and the first stage is to slowly spool it up to see how much the servo needs moving, and in which direction, so that the helicopter will hold at a reasonably steady heading at around 50% throttle.  

To adjust this you need to move the servo back and forward on the boom until the tail holds as steady as you can get it.  Don't forget to pinch the mounting screws each time or it will move by itself.

Once the servo position is correct, and the servo horn is still perpendicular to the servo, adjust the gain on the gyro all the way up, and then swing the helicopter left and right by hand to check that it is operating the tail servo.

SETTING THE GYRO ITSELF

DON'T BE TEMPTED TO EXCEED 50% THROTTLE ON A TURNTABLE

The next thing to do is to reconnect that single yellow wire to the RX. It goes into Channel 5, next to the main gyro connector.  Once this is connected, make sure that you disconnect and then reconnect the LIPO so that gyro can reinitialize correctly

Make sure that  you have the gyro switch in the '1' position, which is DOWN, so that the gyro is in RATE MODE

Now turn the gain knob on the top right of the TX clockwise to about the 12 o'clock position, and spool the helicopter up to no more than 50% throttle to see if it holds the tail, keep increasing the gain until the tail holds by itself, or it starts to "wag" by itself. If it wags, reduce the gain a little until it stops.  I recommend that it is always worth while disconnecting the lipo each time you adjust this so that the gyro centres itself again after every change.

The final change you can play with is the limit control on the Gyro itself.  This controls how far in total the servo arm can move, and can be used to adjust the amount of throw the gyro makes to soften its effect.  Do not change the DELAY unless you really think you need to, as it is normally only necessary to do so if using a very fast, expensive tail servo.

Now to check the gyro really is working as you hope, make rapid throttle changes and see if the tail holds without wagging.  

You can experiment with the delay setting if you wish, but that is really only provided for those of us that are using really powerful and fast servos to hold the tail, so for the stock Esky servos, or even servos such a the TowerPro SG90's, you will almost certainly want the delay set to the lowest setting possible.

Now the gyro switch will switch it between RATE and HEADING HOLD modes. 

NB - the gyro switch settings on the 2.4GHz Esky 6 Channel TX are :-
0 = HH 
1 = Rate 

which is back to front from most other TX's...

YOU DO NOT HAVE TO DO ANY FURTHER ADJUSTMENT FOR HH MODE, although you may well find that you need to use the rudder trimmer to adjust for the dreaded servo creep when in HH mode.

However, if you do need to make any other adjustment to the gyro gain, MAKE SURE YOU SWITCH IT BACK INTO RATE MODE BEFORE DOING SO, OR THE CHANGES YOU MAKE WILL BE IGNORED (Thanks go to hindsight for this additional tip)

A few more tips and points

Before connecting the LIPO, always make sure the gyro switch is in position 0
so that it is in HH MODE.  This gyro should ALWAYS be initialized in HH mode

When the gyro has finished initialising, and when it is in HH mode, The RED LED LIGHT should be ON. You should never need to fly it in RATE mode to be honest, so always ensure it is position 0, which is HH. The ONLY time you need rate mode is to set the gyro up initially.

It is PERFECTLY NORMAL for the red LED light to blink when touching the rudder stick, it simply means the gyro is working. It should blink, but it should also go solid again when you are not touching the rudder. 

To check the mode easily, move the rudder stick in one direction, and check to see if the tail slider stays in approximately the position you moved it to when you centre the rudder stick again ? (remember: if it does stay put it MEANS IT IS IN HH mode, if it centres immediately, it MEANS IT IS IN RATE mode)

It is NOT NORMAL if your gyro blinks when moving the cyclic stick. 

That's all there is to it.......