I am baffled!!

[gagallagher04401]

Ok everyone I need some help figuring this out.

Took the cub out tonight, last time I flew it, it was fine. Tonight took it up, have it setup brushless, flies level, same as always. As Icome out of a turn with it, it pitches upward hard, sometimes does a complete loop. If anything the planes should want to go down in the turn, I was thinking it was just me, not flying this much and flying my other more advanced planes more often. SO I landed looked it all over, everything appears to be fine, nothing binding, servos not loose, apears fine on the ground. I tried it 3 or 4 times same thing, I had my father flying it as well, to rule out it was not just me. Did the same thing to him.

Summary....

So You go into a turn, and then turn to come out of it, and BAM! pitches upward as if I yanked back on the elevator stick, I have to push the plane back down.

the only thing I have not check yet is the motor/ mount etc...

This one has me stumped.

Thanks everyone. I hope some one can help me out.

George

[luvofthagame]

Quick thought...check the nut on the back side of the prop...I've had my prop pop out a bit and turn during a (cough,cough) bumpy landing,lol...should be seated in the prop...also, maybe you had the wing more forward?...lastly, could you have possibly mixed the channels together?...good luck...

[gagallagher04401]

I will check the prop area. nope no mixing, kept it as stock, and basic as possible for my Dad when flying it. Wing has not moved.

[ginginho]

I doubt George is using the stock prop with a brushless setup, but what would I know?

The only thing I can think of at this time is whether something is moving inside the fuse when banking and messing with the CoG, perhaps the battery pack.
I have had that happen before (velcro on pack came unstuck) and had an interesting flight as it knocked an aileron servo extension cable, disconnecting it.

[gagallagher04401]

Ginginho You are correct, not the stock prop it is a GWS 1060 prop, collar etc...
The battery is the same spot as always, but will double check to make sure it is not moving. It is vertical velcoried against the front side of the fuse wall.
Servos are still glued in nice and tight, Rx is still stuck nice and tight inside the fuselage. The ESC is zip tied up front in the cowl.
d**n plane lol

Thanks

Very quickly running out of things to check...

[luvofthagame]

Hmmm...how about the servo rods? Possibly bending under pressure on the turns and causing something funky to happen? Loose struts? Rubber bands wearing out? Oh, I'm thinking check the rudder throw. Now that I think about it, my rudder goes so far left that it actually touches my elevator. Could this be happening a little more severely to you? I could see it being that more than anything. I'm really shooting from the hip, strange...

[gagallagher04401]

Yeah I will check it all.... again, everything moves, and appears fine, has to be something dumb.

[gagallagher04401]

Ok checked everything AGAIN! Have to fly her again, and see. If it is not resolved now I don't know if it ever will be.

Thanks everyone
George

[toff]

Hi George,
OK: RX: are You using an Orange RX? There have been a few reports of bad orange RX's on RCGROUPS.com
Have you checked the motor mount? My motor mount came loose, and made my SC yaw like crazy. Didn't realise my mount was making my plane fly sideways.

[flydiver]

I'd start swapping out components. This was an occasional known problem back in the 'old days' with 27MHz. There was a bad solder joint in the RX feeding info to the servos. G-forces would flex the bad/cracked joint and make the affected servo go nuts. It only happened while flying. Sitting on the bench did not stress the joint so it worked OK.
I had it on 2 different RX/ESC and others did also.

If you have a different RX, I'd try that first, then the ESC, then the affected servo...maybe servo before the ESC.

You already know to go over control linkages carefully.

[gagallagher04401]

Ok checked whole plane! took everything aparts looked it all over. Put it all back together. Nothing out of the ordinary. Everything was tight, nothign broke, etc.. Took it out last night to try her out. Flew as if it never had a problem. Everything seems great. LOL

So.... thank you EVERYONE! not sure what it was but she is fine now.

Thanks again
George

[flydiver]

Hmm...that would seem to indicate a bad electrical connection that improved by re-connecting or maybe a loose control connection (dubro?) shifting under certain stresses.

[luvofthagame]

Congrats...glad your back up and running...

[hounddog]

Glad you sorted it. Was going to suggest another possibility with a non stock motor and a bigger, heavier prop........

Gyroscopic precession.