Thinking about getting into Heli's or have questions, Let me know!

[Biff]

Heading mode. Uhhhh,,,,?

[Nitrohuffer]

	Quote: Originally Posted by Biff
	Heading mode. Uhhhh,,,,?

I was in the same boat for while, these things seemed very complicated. Gyro technology has done wonders for the rc heli in the past 10 years. Gone are the days of revolution mixing (tail to collective). I couldn't imagine setting up a heli without a gryo.

Here we go, get your notebook. Cliff notes are at the end of the post.

First thing to start with is what does a gyro do, and how does it do it. Basically you have two types, mechanical and piezo. I do not think anyone still sells the old mechanical gyros. The mechanical gyros will have a buzzing sound coming from the sensor unit. They use an electric motor with two flywheels, one on each end of the motor shaft. And this is where the noise comes from. To understand how it works hold a spinning bicycle wheel by the axle and try to turn it, you will feel it resist you moving it. The flywheels in the mechanical gyro are mounted on a pivot and a sensor measures the deflection of the motor/flywheels when the helicopter makes a sudden movement. The piezo type gyros work with no moving parts. It uses a triangular crystal (or a silicon ring in the case of higher end models) with a piezo element on each side. The piezo element is used in a lot of watches to make the beep sound from the alarm function. The material not only can make sound but also sense it. So it is used in both speakers and microphones. Two of the piezo elements on the crystal are set to sense vibration and the third one is setup to vibrate. When the helicopter is not rotating the vibration traveling through the crystal hits the other two piezo elements at the same time. When the helicopter is rotating one sensor will have a stronger signal then the other. It is a very efficient design and has a lot finer degree of resolution then the mechanical type. In addition power consumption is greatly reduced as there is no spinning motor to power.

BIFF! WAKE UP! Here's you answer! I know this is a very dry subject but I find it interesting and it good to know what is going on inside that little plastic box.

Heading hold (hh) and standard rate or normal(non-hh).
In non-hh mode the gyro just dampens unwanted movements of the tail. To keep things simple lets say you are hovering and a constant wind hits the helicopter from the side, the gyro will keep the helicopter from suddenly swinging nose into the wind, but the helicopter will eventually drift nose into the wind. All the gyro does is to prevent any jerk type reaction.
In hh mode the gyro will keep the nose pointed in the same place until you tell it to move. You can fly sideways with the rudder stick in the center and the nose will remain pointed in the same direction.
If you have not used heading hold before then you will notice in fast forward flight that when you make a turn, the tail will not follow the helicopter, you have to give some rudder in your turns. Another thing is that you'll notice the rudder stick feels different. In heading hold, the amount you move the rudder stick from center tells the gyro how many degrees per second that you want the helicopter to rotate. The gyro moves the rudder servo however much it needs to obtain the requested rotation rate. With a standard rate gyro if you did a slow pirouette (one rotation) with the wind then to keep the helicopter spinning at the same rate you would have to move the rudder stick more as the tail is going upwind and less as the tail goes downwind. But with a heading hold gyro, it will tell the rudder servo to move more or less to maintain the constant rate, you just keep the rudder stick in one place.
Due to typical marketing ploys you will see many names for heading hold. They all are just different names for the same thing. The different names are just because each company wants to make it seem like their version is more special then another companies. AVCS = Tail Lock = Smart Lock = Heading Hold

Cliff and Biff notes:

Gyro's sense the yaw of the heli due to torque changes by the main rotor, and send a signal to the tail servo in the opposite direction to correct the movement and make it stay put.

Non heading hold will allow the heli to act like a weather vane (sp?) and point itself into the wind that is hitting the fins on the tail. Heading hold will keep the tail locked in one direction until stick input is entered (allows for easy sideways flight)

[2.6m-rod]

thanks for this info,it has helped me to understand gyro's.i am new to heli's . i am thinking of buying a raptor 60, gy401with 9245 servo.
what other servos would suit this size heli and are digital ok to use
battery 6v nimi2700 ok ??? is 6v ok for gyro


regards rod

[Flyinfool]

Rod
Digitals are great for helies.
The 9252 is one of the most popular servos and works very well and is not too expensive.
Your 6V NiMh pack will cook or at least drastically reduce the life of the gyro and 9254 servo. If you want to run the 6V pack you will need to put a 5V regulator on the Gyro and servo.
2700 mAh is the minimum pack that I would run with digital servos.
I have all 4000+mAh Lion packs in all of my helies from 50's through Gasser's. With your pack be sure to check it before each flight with an expanded scale voltmeter under load. You may just need to recharge at the field more often.

[Nitrohuffer]

What he said I'm sure you've got a fromeco laying around, drop it the lowest they go and you will be fine. That's what Jeeum did with the relion 4000 pack.

[Flyinfool]

Watch out for the Fromeco regulators that are made for giant scale.
They WILL fail in a heli.
Fromeco makes a couple of special regulators for heli use.
There was tons of testing done and the only conclusion is, the Giant scale regulators do not last in a heli, they burn up. None of the engineers at Fromeco were able to figure out exactly why.
The dedicated heli regulators have huge heat sinks on them.

I have had good luck with both the Duralite and MAH batteries and regulators in a heli.

[Nitrohuffer]

Wow. That is news to me. I never heard any problems. My mah switched regulator doesn't have a heat sink, should I worry? I'll get some more info from Kurt and Mike @ fromeco about that failure issue. The Arizona by Fromeco is the cats meow for heli's anyway.

[2.6m-rod]

thanks for the info guys,i want to set it up right the first time and fly the ringers out of it.



rod

[Flyinfool]

My MAH regulators do get warm but not hot in my helies.
The failure issue is why they came out with the Arizona regulator.

[Boogie]

Nitrohuffer:
I am only 19 now and can't afford a great heli. I've never flown helis before but can do some ricks onthe sim together with zero altitude inverted hovering. I will be probably moving in october to a very small flat (so small place to keep everything) and as I will be studying I won't have enough time to go to the field. I have a bit of experience with both glow and electric so that really doesn't matter. I was thinking of going with a T-REX 450XL(CDE)CCPM with either align motor or hyperion YH22XL-3900 motor together with tower pro 30A ESC (airplane version). The other option is a RAPTOR 30/50 v2 but that envolves much more money and is more problematic. Is flying a heli really worth trying??

[Flyinfool]

	Quote:
	Is flying a heli really worth trying??

Now thats a loaded question to ask in a heli thread.
My experiance is that the electrics and gassers are both more problematic than glow. Glow is a fairly mature sience in rc helies and the answers have all pretty much been asked and answered already, and incorporated into the various designs.
A small electric like a Trex will cost about the same as a 30/50 size glow heli.
The small helies are much less stable, harder to fly, and do not put up with as much wind as a heavier glow ship can.
But then you should not be trying to fly a glow ship indoors, you can do that with a small electric.
Disclaimer; a small electric should not be taken lightly, it can still do significant damage to anything it hits.

[Boogie]

That was a joke
I am still wondering if I like all that bling bling stuff. I will have to spend a lot of money for this project and want to know if it's really worth it. On the other hand I won't have time and place to fly anything else that helis. I know anything about precauations. As for learning to fly I will have a big gym and pro's help so don't worry about that.