Head hold?

[Robman]

Do most of you fly with it on or off? What is the advantage of either?

[OzarkCopterBum]

I'm kinda curious too. I'm just hovering and forward flight but I leave HH on all the time.

[RSL_Mongoose]

If you spend the $$ for heading hold use it, I can't remember the last time I used normal mode

[Hotwings]

yeah, what mongoose said, learn to fly the tail in HH, it's the way to fly.
Flying the blade is tough because you can't anticipate where the tail (non HH) is going to go.
it's fun, just not precise. c-ya Ron :glasses:

[WayneBrown]

Always in HH.
Unless changing linkage, or confirming something, or troubleshooting the tail...

[keith shaw]

Just my .02! First learn to set the tail up in rate mode! It should be pretty much stable with maybe just a little tendency to yaw one way or the other, but only slightly!!! Work to get it down to zero if you can, in rate mode! Once the tail is stable in rate mode, then you can switch to HH. Otherwise, you'll work your tail servo to death and burn it out, fast!!! In either mode, you need to learn to fly the tail, as if you were flying a plank that needs a lot of attention to the tail, ie, J3 Piper
Cub. The advantage of either....in HH, it makes flying nose in a little bit easier, but when it comes to 3D...... there are many manuvers that couldn't be done without HH! You simply couldn't correct the tail fast enough! :wink: :)

[Ivan]

By definition, HH mode is a calculated position, based on acceleration, direction and time. IE the gyro knows how fast, which way, and how long the rotation occured and inputs a correction that will bring it back to its origional position. In practice this correction is minute enough to be undetectable.

Normal mode is just an opposition to movement. If the heli tries to rotate in one direction, the gyro inputs an opposite command. If the heli is not moving on that axis, there is no input. A sudden gust of wind knocks it off course, the gyro tries to oppose that movement, but when the movement stops, so does the gyro, in the new position. Normal mode is prone to "weeathervane" in wind. This also lets the tail track better in forward flight, whereas in Heading hold, you have to fly the tail around the turns. Also since the tail isn't commanded to a position, you will need to set revo curves, and accelleration mixing, for each mode. These are special mixes that mix the tail to the collective, and as you move the collective, the tail gets some extra push, so your thumb doesn't have to.

Rate gyros can be either normal or heading hold. The term Rate Gyro comes from the fact that the gyro tries to maintain a certain rotational rate as dictated by the stick position. If you move the stick half way, the gyro will try to maintain half of full rotation speed (simplified, but you get the idea). Most piezo and solidstate gyros are rate gyros.

Which one should you use? Which ever one you like. Teh vast majority of pilots use heading hold, because when you start inverted, backwards and sideways stuff, it is much easier to keep the tail under control. Most guys that have scale machines use normal, as it is easier to make the tail track in turns, and looks more realistic. I started flying helis when CSM just released the 360 (i think), which was the first HH gyro, and they were way out of my league at the time, since everything I had was used. I had an old "spinner" gyro, which was not as good as a cut rate piezo. When I got a telebee, it was like flying a different machine. Much more fun, but I had to learn how to fly the tail, which took about 5 minutes.

Hope this helps you all understand a bit more about gyros.

[Robman]

Thanks For the replies.. I've got the tail trimmed out in rate mode but the nose drifts the the left when in a hover in HH....How can I stop it?

Rob

[WayneBrown]

Is it possible you have a revolution mix also programmed to come on when in HH?
fishing maybe...

[tempest]

Never trim when you have got the hh Mode on because it will turn the heli all the time. When you have got a switch for hh on off: switch hh on and turn the Radio and the model off. Then turn the Radio back on and switch the model on without touching the throttle that it can neutralize.
Thats it

If it doesn't work put your trim level to 0 because on heading hold you don't really need the tail trimmed out. It will trim by it self.

What Gyro do you have? if you have a 401 you always need to start the heli in avcs mode to neutralize right. On a 601 it is not necessary.

Andrew

[DavidH]

You don't say which gyro you have. But if you have a Futaba GY gyro. You need to have Normal mode and AVCS mode to have the same neutral. To do this you should take the switch on the transmitter that controls which mode the gyro is operating. Flip this switch back and forth between the two modes 3 times in one second. Then put it in AVCS mode. Now AVCS mode should have the same neutral as Normal mode and not drift.

David

[Robman]

Sorry It's a futaba 401..

thanks

[tempest]

On this Gyro you should start always in AVCS mode because it will neutralize better.

Andrew

[tnreefguy]

Here we go again. I never start or carry any of my models in HH. I carry it to my takeoff point and then switch it into HH. This prevents the model from spinning to the last known positon it was initialized at. But before anything gets started you can correct if you leave it in HH all of the time. Just give a little rudder input one way or the other or flip your swith back and forth a couple of times.

[DavidH]

From the GY 401 instructions:
Using the AVCS mode correctly
An AVCS gyro is an angular velocity command type gyro. The gyro constantly
compares the transmitter rudder operation signals and gyro internal
reference signal (transmitter rudder neutral signal) and controls the helicopter
tail rotation speed accordingly. Therefore, for the AVCS function to
operate normally, the rudder neutral signal must be memorized in the gyro
before flight.
•Rudder neutral signal memorization methods
[Method 1] When the gyro power is turned on, the transmitter rudder signal
automatically received at that time is assumed to be the neutral signal and
is memorized. The gyro is normally used in this state.
[Method 2] Rapidly switch the transmitter sensitivity switch between the
AVCS and normal modes at least 3 times at a 1 second or shorter internal,
then set the switch to the AVCS mode position. The monitor LED flashes
instantaneously and the rudder signal is memorized. If the trimmer was
moved during flight, the memorized neutral position can be updated to the
current neutral position by repeating this operation. When performing this
operation, land the model and hold the rudder stick in the neutral position.


The operation below will return the servo to the neutral position. My GY gyro has not been in Normal mode for a couple of years now. I use this method below to center the servo before taking off.

•Rudder neutral check method
In the AVCS mode, the servo does not return to the neutral position even
when the rudder stick is returned to the neutral position. When you want to
check the servo neutral position during linkage neutral check, etc., select
the normal mode, or remain in the AVCS mode, and move the rudder stick
left and right at least 3 times at an interval of 1 second or less, then immediately
return the stick to the neutral position. This operation returns the
rudder servo to the neutral position.


David