hello all, my buddy has a wierd problem with his nexus, its an upgraded nexus to a .46, flies very nice except something wierd, when its hovering or in foward flight it wants to face in the direction of the wind, we hover nice and steady and it automatically starts trying to face in direction of the wind, then it becomes steady and does not move anymore, we've tried giving it less gain and then more, either or it still does the same thing, does anyone have an idea on what may cause this, we are pretty much lost in this one, any help is greatly appreciated. Oh it has a piezo gyro if that makes any difference.

the gyro you have may not have enough torque to hold heading try a radio brand gyro to fix the problem.

A non-heading hold gyro will not, maintain a heading it will tend to weather vane into the wind.

so he basically will be needing a new gyro? im sorry I'm not familiar with the term non-heading hold gyro, if so would you recomment a gy240 or 401 gyro? we have a feeling it has to do with the gyro though not sure, if that is the case we'll go ahead and head to the local hobby story today to pick one up.

The GY-401 is a excellent gyro I would recommend it over any-other.

Make sure you get a good high speed servo with it, like the Futaba 9253. I have the Hitec 5925 and it works great(I couldn't get the 9253 at the time).

mbbaj2001- gyros don't torque

In the old days we accepted that the helo would drift to point into the wind, with heading hold gyros the drift is minimized but it will still slowly drift, by slowly I mean 10° in a minute, most helo flyers won't even notice the drift but it's still there. Your regular piezo gyro is working how it was designed and my recommendation is to learn using it and move up to a better( more expensive) gyro later in the game.

I just wonder why nobody else said that a hh gyro drifted when I asked the question on rcu.

I really got fustrated trying to fix my hh gyro when it drifted. I am glad to find out that I really don't have a problem. The drift never bothered my flight performance, but I really could not fly a heli that I thought had a problem.

Fear, Sounds OK to me, I've been flying Heli's for many years, just got my first HH gyro last year WOW what a difference.

Bottom line though - Get an experienced Heli pilot to check out the Heli setup and test fly it for you. Nothing can make learning Heli harder than a setup thats not just right.

For those with HH Gyro's that seem to drift;

Note: A Heading Hold Gyro will appear to drift if you touch the rudder trim after it locks in.
The GY-401 manual mentions this but it's not something you think of right off. And they dont make a big deal of it.

Note 2: Zero out your Revo mix curves, except the one you use for Normal Gyro setting, I switch the Revo off when I exit Normal to any Idle-up mode.

The following is for GY-401 Gyros, it may help with others;
For setting up;
Do not use HH mode. Use normal, get the trim set and zeroed mechanically. Then land the bird and re-cycle power to lock the HH mode in. <also switch off Revo>
Once its trimmed out, I generally leave it alone!

For first flights;
Start the power on of the Gyro in HH mode, let it lock in, then switch to non-HH mode for starting the engine and moving the chopper to the take off point. Switch to HH and get it light on the skids, it should be rock solid in yaw. If OK, try skidding in yaw, make sure it stops when you release yaw input! This will point out if you have it set up backwards. I've done it myself. You have never seen a pirouette like a backward gyro! It wont stop, just reverses rotation direction.
IF that is OK, lift off a few inches and play with yaw. If it "hunts" or oscillates, land and reduce gain. You reduce gain by reducing ATV or "Max Throw" in the channel controlling the gain. There is a tradeoff between "Hunting" and Hold Authority so you might want to live with a little wobble here.

I take off in normal mode then switch to HH. This ensures I havent left it in HH and moved the Heli, which results in a very abrupt yaw to where it thinks it should be pointed!

If you do this you shouldn't have problems.
One last trick, with the GY-401 you can flip back and forth between HH and normal mode 3 times each and this will reset the HH mode lock, eliminating any drift from odd things changing.
(Like if you really think you should play with the Yaw trim)
NOTE; You MUST land before doing this. The gyro has to be stationary to get a correct heading lock.

Keep the rotor out of the dirt!!!

Ramjet

Regarding the machine facing the wind - it is perfectly normal for the helicopter to do that with a standard Piezo, non heading hold gyro.

You may just need to get a higher torque servo for the rudder !

I also recommend the GY401 with the 9253 servo combo

Thats the bottom line, Just like Mike Mas said it.

You want it to hold the heading solid, Ya gotta buy Heading lock.
BUT;
Piezo is fine for learning and sport flying.
Hell, I did it with an old mechanical gyro.
It's actually going to make you fly the rudder more, So isn't a bad thing to learn. One recommendation, practice while facing the wind until you can hover nose out ok.

Ramjet

Like RamJet mentioned - it's best when your learning to use the rudder (tailrotor) control as much as possible to develope your reflex.

As you progress, the heading hold gyro is fine for aerobatics!

HH gyro calculates the drift angle and is always updating the signal to help compensate for the crosswind.