To achieve good flight it is important that the heli is mechanically perfect. In addition to the usual rotor head setup essentials the following aspects must be achieved -

1. The distance between the top of the mainshaft collar and the underside of the rotor headblock must be the same on both shafts, use a pair of dividers to measure.
2. The pivot support must be midway up the pins of the stabilizer anti-rotation arm and in an identical place on both heads, adjust using the servo arm links.
3. Both swasplates must be completely level, adjust using the servo arm links.
4. The pitch control arms must be of equal length.
5. Blade pitch must be equal all round

The final aspect of mechanical setup is to set the helicopters centre of gravity at midpoint between the two mainshafts. I measured this carefully and marked, I then used a piece of string to suspend the helicopter and check for balance with the battery fitted. In my case I added a small amount of lead ballast at the rear to balance the heli, this was done with a small amount of lead strip wrapped around the rear frame as far rearward as possible to keep the amount used down in weight.

Radio Setup -

The following is a rundown of Radio setup using a Futaba T7CP radio, the settings are specific to my CH46, variances will exist. Set the yaw axis gyro to 100% gain, the elevator axis gyro to 50% for inital setup -

1. Select a H-1 helicopter type, all pitch mixing is controlled by the MS-025 mixer.
2. Set throttle curve to all '0' for initial setup, leave pitch curve at 0,25,50,75,100.
3. Turn on reciever and check movement of all servo's on my heli CH3, 4 and CH6 are reversed. Ensure throttle is set at 0% and turn off Heli and controller
4. Center servo arms mechanically (it is not possible to use sub-trims) and check swashplates are still level.

5. Using a pitch gauge accurately set blade pitches to 0', ensure that pivot support is still midway up the pins of the stablizer
6. Ensure REVO mix is set to INH (inhibit)
7. I have -30% EXP on Aileron, -40% EXP on Elevator.
8. Set GYRO to standard mode, assign a value of 75% to the relevant switch (I have set 80% after experimentation).
9. Set P-MIX1 to CH2 master CH4 slave, set high and low values to 50%

Flight Setup -

I have maintained a straight line throttle curve of 0,25,50,75,100. My pitch curve is 0,33,61,88,100.

Take off should be as normal at about mid stick, the heli should lift straight off. If the front or rear of the helicopter lifts off first reduce pitch mechanically one turn at a time until both rotors lift together at the same rate. Where the front or rear lifts off first the heli will tend to rotate around its yaw axis at the same time due to the increased torque form the relevant rotor, it is important that both rotors have identical pitch. Looking a the rear of the heli in flight if all is correct the rotor discs should not be at too high an opposing angle to keep level hover.

Once the pitch of both rotors is identical and neither the nose or tail drift alarmingly fine tuning can be completed in the radio.

With the MS Gyro I found that a higher value is required of 80% to stop the tail drifting too much.

The elevator gyro mix on P-MIX1 controls the sensitivity of the pitch axis at hover and in forward flight, a value a great deal higher than 50% causes the heli to oscillate heavily in th eelevator axis, I have found up to now a setting of 50% works fine.

The heli takes a little getting used to as the yaw axis pivot pitn is about the centre of the heli and response is slow.

Once setup the heli flies very well.