Gyro acting funny........

[misterg74]

Was hovering my heli earlier today about 4 minutes in my tail stopped holding had to land it n adjust the trim on the tail ...... Got it back up was fine for a second then it just started spinning in circles the other way ....... Bad gyro?????? Or could it be something else? Am still using the stock gyro with a DS3400G tail servo but all has been fine for about a month.

[SeaComms]

Could be belt drive setup starting to slip. Hold the main gears and try to rotate the tail and see if it will slip. Sounds to me like it slipped, then gripped etc..

Especially (or only really) if the initial spinning was nose left as the belt slipped, then you trimmed it up then it went right when the belt gripped again.

[misterg74]

Thanks i'll try tightening the belt up a little ....... I guess by rights as the belt heats up it would stretch causeing it to slip?

[misterg74]

On that note .........Exactly how tight should the belt be????

[SeaComms]

No, the belt shouldnt really stretch as it warms up, for that matter it shouldnt really warm up either. The construction is similar to that of the fan belt in your car, as in rubber / material composite that should not stretch much at all over its life.

There is a window in the font right side of the boom, you should be able to push the belt halfway across to the other side quite easily. Really it just needs to be tight enough to not allow the teeth to skip. If its too tight it will suck a huge amount of power and run your batts flat in half the time. Too loose, and it will slip and cause the symptoms you are witnessing.

Thats not to say it is definately your problem tho, you may have teeth stripped off the drive gear for the belt, the drive gear may be slipping on the shaft etc, thats why I suggested holding the main gear and trying to turn the tail rotor. If there is any slip anywhere you should be able to work out where. A notched slip is the belt jumping teeth, a slow smooth slip is the likely to be the drive gear slipping.

Good luck, we dont need anything else to make flying these beasts harder!!

[misterg74]

Thanks a lot ............ Guess I might as well just check Everything anyway ..... Just in case..... Thanks again for your input:thumbup:

[misterg74]

Ok so basically my tail just won't hold with a battery in and no throttle the tail servo twitching like crazy with the slightest movementof the heli ....... with throtle the tail is wagging left right n visa versa a good half circle .......... Has to be the gyro ? ....Right???

[jimzpsd]

Ok so I tightened the belt when i start to hover it wants to spin nose left then suddenly will start spinning nose right. Please don' tell me it's the gyro?! :arggg::arggg:

Odd, I am having the same problem. In fact, as I move the rudder pitch, you can actually watch the linkage change pitch slowly all by itself. And if I trim it all the way to the right, to make it neutral, it begins to move slightly to the left,...all on its own. Perhaps the gyro has to acclimate to the outdoor temps.? It is 50 degrees F, outside, and 70 degrees F, inside.

[misterg74]

Yeah mine started out doin that now it is just going crazy!!

[jimzpsd]

I can hover mine safely, and I can also control the rudder, but............I don't trust it. I read that you must let it adjust to a diff. temp. extreme for apprx.10-15 mins., (page 25 of manual, the last paragraph). I've had mine outside all the time w/temps like this w/no problems before.

[misterg74]

I did let it adjust for temp even though there is only about 5 degrees difference. The thing is it started to do this about 4 or 5 minutes into a hover. I guess I'll shell out the $130.00 for a gy401 alreday upgraded from the crap servos it came with ........... Hmmm .... who knew when the box said ready to fly it shoulda read ready to BREAK!!! :thumbdown: :arggg:

[carlo_the_wonder_frog]

don't feel too bad, just about everyone replaces the servos and gyro.

[Wolfpackin]

I got my stock gyro with a Spektrum DSP75 to work really well.
Watch the Finless video on Align/Telebee Peizo Gyro's, that's how I got mine to behave.
Some of the more important things are to move the ball on the servo arm to the center hole and then set up for no drift in rate mode before tweaking the setup in HH. Finless does not mention that.
Then you also should turn the gyro's gain pot all the way CW to 100%, I found this does make a big difference.
Use subtrim to stop the servo creep as Finless describes in the video, you may have to adjust that by a few clicks depending on how the gyro reacts in flight.

Good luck, let me know if you have any questions, but do watch and follow that video.

[misterg74]

Thanks I'll do that ....... Am still gonna order a 401 ...... It seems everyone has good luck with them ..... It does amaze me though that e-flite markets the 400 as a 3d heli and mine won't even hold together for simple hovering without a REAL crash other than couple blade strikes.

[jimzpsd]

Mine seems fine (for now), almost back to normal settings w/o a single glitch. But if it continues I'm gonna give their customer support tech. line a call, perhaps they are aware of this complaint and already have an upgrade/cure for it. ( :badair: )
I was advised ( by various members) to purchase a T REX 450, cause they come with superior components already installed, oh well live and learn. Perhaps I should have listened. I paid $385.00 for mine so I can't really complain.