The 3DPro head is a basic design, it takes a bit of work to get everything moving smoothly. I upgraded to the alloy components as I wasnt happy with the stock parts, particulalry the seesaw.

I applied all the usual basics of ensuring all linkages where of equal length, servo links at right angles to arms etc before I started.

I am using a typical 3D setup which means that at 50% pitch in the TX the mainblade pitch is 0', this gives negative pitch for values less than 50% pitch, positive pitch values for more then 50%.

The principal of setup is the same for the Hornet helicopter, see PART 6 of V1 for a detailed explanation.

After a basic setup I set about flying the model.

Trimming out did not take long as everything is well balanced, I flew the tail in rate mode to begin with just to see how the heli responds.

I dialled in pitch settings until I had the head spead I wanted, currently I have a standard throttle curve of 0%,25%,50%,75%,100% with a pitch curve of 61%,71%,84%,97%,100% culminating in a maximum blade pitch angle of 10'.

The 400DH motor is awesome giving huge amounts of performance, fast forward flight is terrific although I havent done anything inverted as yet.

The tail is rock solid and the belt drive runs completely smoothly with absolutely no issues, I am really pleased with the results so far.

Tail Setup

The following is a detailed description of how I set up the tail using the GY401 Gyro and an Ashtek digital servo together with a Futaba radio.

The heli has the gyro at the rear of the main horizontal member with the tail servo accomodated in the right hand frame.

The plug that has all 3 wires is plugged into receiver channel 4, the plug with only 1 wire is usually plugged into receiver channel 5

Plug the Gyro into the female plug

The servo arm should be in a 90' position with the tail rotor set (dependent on rotation direction) to give about 3' pitch force in the opposite direction

to the main rotor rotation, this is done by lengthening or shortening the tail control rod by screwing in or out the ball links

The gyro is set to DS - ON (digital servo)

Delay Trimmer set to 0 initially

Using the limit trimmer set the degree of travel so that no binding takes place on either throw of the servo

In the GYRO menu of the radio set the ATV gain value to 50% for both normal (rate mode) and heading hold mode.

In the GYRO menu determine which switch selects rate or heading hold mode and position the switch in rate mode.

Ensure that the Gyro switch is still set in rate mode and attempt to fly the heli in as near wind free conditions as possible.

Whilst still in rate mode adjust the servo pushrods length by screwing in or out one of the ball links until either no tail drift is present or very little.

When this is achieved land the heli without using any rudder action and quickly throw the Gyro switch 3 times ending in heading hold mode. This wil set the home position for the servo arm in HH mode.

From now on always turn on the receiver with the transmitter switch in this position if HH mode is desired.

To trim out the tail in HH mode use the ATV gain value on the Gyro menu as follows -

Fly the helicpter in a stable hover and watch the tail.

If the tail wags decrease the gain value until stable.

If the tail will not hold steadily increase the gain value.

For most purposes 50% gain is fine, however in this case with the high head speed, extended tail and larger than standard tail rotor blades on a relatively light helicopter I reduced the gain to 38% comfortably although I may increase this once more forward flight has been possible. Always aim not to have too much gain as this will put a strain on the tail servo as it hunts to find its home position.

If the tail has a tendency to 'bounce' quickly after a tail manouver reduce the 'Delay' trimmer should be used to reduce the action of the servo in response to the Gyro, I have only ever experienced having to use this with non Futaba servos.

Set the degree of EXP for the rudder to give the degree of precise control you wish around the centre stick position.

Finally experiment with the rudder D/R rate to find the speed of pirouette that you wish the higher the value the faster the spin!