_BOON_

Just upgraded my heli with a heading hold Robbe 3D gyro
I can't seem to get it working and the intructions are not really understandable.
Do I have to readjust the servo and or linkage arms also when turned on via the Tx the rotor pitch goes all the way to the right, is it ok to start the heli up at this stage?

Regards

boon

Galifrey

make sure you do not have any subtrim on the radio...

you should be adjusting the mechanical rod length, not the servo sub trim...

_BOON_

I have the subtrim set up on the Eclipse 7 in standard mode when I flick over to HH mode on channel 7 its not right.
If I setup HH mode via pushrod when I flick back to standard I'm sure it will be out while flying
I'm getting confused.

boon

Galifrey

HH gyros are Yaw rate demand gyros, any sub trim generally is interpreted as a command to turn (yaw) the helicopter...

There are some exceptions, however if the tail servo wanders in HH mode it is trying to turn the heli and increasing the servo travel as it has not sensed any yaw... you can try adjusting the subtrim until the servo doesn't wander in HH mode (like the JR5000T asks you to do) you should be able to switch from HH/normal/HH and the servo should remain where it was in normal mode... if not then the gyro is not centred to the same as your radio...

Why would you want to fly in standard anyway, just get it right in HH mode...

Vortexgen

regardless of the trim, when you turn power on to the model, the HH gyro should reset its own neutral point.

i.e you should trim the chopper in normal gyro mode, land, shutdown, and turn the power to the model off then on again. the HH gyro will now recognise the set trim position as the new neutral point. (this in case you want to switch back to normal gyro in flight, at least you know it will be trimmed correctly)

also, after switching power on, dont move the model for about 2 seconds which allows the HH gyro to callibrate itself (allign to the current heading/angle)

with the GY401 (futaba) another method of resetting the Neutral point is to turn the gyro off and on 3 times within one second. (switch on the Tx), not sure if this will work on the Robbe.

Also, i recommend checking Revolution mixing is inhibited when in heading hold, the HH gyro sees rev mix as another command and will cause the helicopter to yaw around. ( i suspect this is your problem )

another point on HH, the direction your heli is pointing when you start it (eg North) is the direction the heli wants to return to. So if you start it up facing north, carry it into a paddock and set it down facing south, it will want to spin back as soon as it can. you can counter this by simply applying some rudder input and it will now try to redirect itself to the new direction. (after releasing the rudder stick, a new neutral is remembered as its new angle)

You can see this if you move it from its initial power up heading/angle, the gyro will cause tail rotor to go to full deflection until it achieves its original heading.

GY401 has a led on it that tells you if its working correctly in HH or norm, maybe Robbe has the same. steady flash is HH on the GY401.

they work on an angular variation, so any angular movement from its neutral (power up point) will cause the servo to move. obviously, after releasing the rudder stick, it recognises the new position as its new neutral and will maintain this new angle (heading). be aware in fast forward flight, the airspeed wont push the tail behind the helicopter like a normal gyro does (by drifting), rather it will maintain that exact angle to the chopper mast. so youll have to get used to steering the tail a lot more to make coordinated turns.

you may not like it at first, it makes the machine quite different in forward flight, as you conciously have to be putting in rudder inputs to keep the tail where you want it. im just beginning to like mine now after 2 months...

let me know if you need any more help....

cheers

_BOON_

Thanks guys I'll try those tips.
I think I have revo mixing set, I'll turn it off or put to zero on the Tx.

Here's what it says in the book:

-activate HH mode
-watch the tail rotor: it will tend to swing away in one direction in response to minor differences in the radio control system's neutral signal.
-adjust the tail rotor trim until the tail rotor and the servo are stationary (TIP: If possible reduce the trim travel elecronically (e.g. TRIM RATE 30-40%) to provide finer control of the neutral setting.
-activate normal mode.
-set the model to hover and turn the nose into the wind.
-if the model swings around the vertical axix at the hover, land and adjust the rail rotor linkage - but don;t move the trim.
-you may need to repeat this procedure several times.
-once the model hovers without any natural tendency to swing, the model's mechanical system is correctly adjusted in relation the the electronic system.

I think I've done it back to front.
standard first then HH.

sorry for being a bit naive
I'll get there in the end