Flying in the cold and tail is twitching...is that normal?

[imq707s]

I crashed my B400 last week, and today was the first time I've had it back in the air.......it's also the first time I've flown in cold weather (it's 30 out now). The first thing I noticed was that as soon as I got it up in the air and hovering...every second or so the takl would twitch a little. I ran that pack down, and then I checked the belt on it...and it was tight.

I hooked another pack up to it....and this time it did the same thing....maybe a little less.
Next pack...a little less.
The last pack I ran through it, it seemed like the tail was just about acting like it's supposed to.

Do the stock E-flight gyros not handle cold weather well? Could I have messed the gyro up in the crash last week? I went from a 70 degree house, right outside into the 30 degree weather. It seemed like the holder I flew the heli, the less the twitching happened. Do I need to set the heli outside for a while to let the gyro adjust to the cold temps? Is that what is causing the twitching?

Any info would be great.

Thanks

[75scoutII]

Temperature changes have been known to cause drift issues, the documentation states that you should let it sit 15 minutes and equalize.

I noticed differences when its 75 degrees in the house and I go out side and its 110+.

I'd let it chill a little, and test again, if it still acts up, then the crash did it in.

[xspare]

Not giving the gyro time to reach outdoor temperature is more likely to result in drift - most sensors will shift with temperature.

There is a potential for condensation, depending on temperature & humidity indoors and outdoors, since warm air is typically moister than cold air.

What work did you need to put it back up in the air? I think it's more likely that the twitch (is it unidirectional?) could be due to mounting issues (foam tape, adhesive degradation, wire routing) or possibly contact oxidation or static buildup with the belt and gears.

[imq707s]

It's wasn't too bad of a crash. I needed new blades, feathering shaft, and main shaft...everything else cam out ok. I cound't really tell if it was unidirectional or not. The tail would be holding very well...then it would just twitch a few times...maybe an inch or two..then it would settle down again. It did seem like the longer I flew it, the less it twitched.

I will charge up all of the battery's again, set the heli outside for 15min, and give it another shot tonight and see what it does. I will let you guys know.

Thanks!

[Tommygunn]

The first thing I noticed was that as soon as I got it up in the air and hovering...every second or so the takl would twitch a little. I ran that pack down, and then I checked the belt on it...and it was tight.

Of course it's twitchin', it's cold outside.


Don't you?

[imq707s]

Well, I just got done hovering my Blade in the dark for a few minutes after it set outside for about 15min. The tail still twitches or "shakes" back and forth a little bit...but definitely not as bad as before. I'd say that it probably moves 1/4" or less to the left and to the right...just kind of twitches back and forth.

Could the gain be too high? If the gyro was set to the max amount right before the tail started to hunt.....would cold weather push the same about of gain into the zone where the tail is going to start hunting again? I'm running 72% right now....I guess I could go lover and see what happens.

Anyone else have to lower the gain while flying in cold weather? Is that what the tail will do when the gain is too high.....shake back and forth a little bit...kind of "twitch"?

Thanks

[xspare]

So it sounds like your tail is twitching but it's returning to somewhere near its original position?

I ask because my heli twitches by slewing 20-30 degrees to the right (in an instant) and then locking into the new heading. If I don't correct for these jumps it would just keep turning to the right. This is what I meant by unidirectional.

[imq707s]

Yes, mine seems to hold its heading....it just sits there and twitches left and right. VERY small movements, but I can still see them. Just back and forth...small little shakes. They come and they go. I did put some new blades on it, could they be out of balance enough to cause that? I was in a hurry to get the heli back together, and never checked them. They are the Align 325 Pro woodies.

[xspare]

I think most folks dial up the gain until it wags and then drop it back a bit. Others have recommended dialing the gain down until it feels loose and then pushing it up a bit.

Temperature could definitely push the stability point. So yes, good idea, drop the gain a few percent and see how it flies.

[75scoutII]

Could be tight belt, or tight pinion mesh. Those seem to cause hunting(where the tail is hunting for the correct spot).

Try turning down the gain, if your in heading hold, don't go down past 51 or you'll end up at zero gain, and then further down under 49 you'll be in rate mode.

Jason.