servos- torque roll?

[sam94]

I have a new plane, and when i first attempted to fly it, it was very twitchy in the air, after inspection it shows that the servos was very twitchy causing the plane to swing side to side in flight.

The servos were probably roughly 10-11gm servos, so i replaced them with my 7.5gm servos, and on my next flight with the new servos it crashed

The crash was like this - i launched it into the air and it went forward a little then suddenly rolled and nosed into the ground.

Could this be because of the new servos i put in.

Please help

[Matt Kirsch]

What do you mean by "twitchy?"

Were the servos moving on their own, jerking around?

That's a definite "no fly" condition. Don't fly until you figure out what's wrong.

As far as your crash... Did the 7.5gm servos twitch too?

If they did NOT twitch, odds are that the plane didn't have enough airspeed on the last launch, and tip stalled into the ground.

If they were still twitching, then the servos probably went hard-over due to whatever interference was causing the twitching.

[sam94]

Originally Posted by Matt Kirsch

What do you mean by "twitchy?"

Were the servos moving on their own, jerking around?

That's a definite "no fly" condition. Don't fly until you figure out what's wrong.

As far as your crash... Did the 7.5gm servos twitch too?

If they did NOT twitch, odds are that the plane didn't have enough airspeed on the last launch, and tip stalled into the ground.

If they were still twitching, then the servos probably went hard-over due to whatever interference was causing the twitching.

well...when i mean twitchy i mean they move by them selfs and randomly twitch

But i decided to fly-BIG mistake

After a crash with the twitchy servos in, i decided to replce the large servos with small er servos (7.5gm), they are not twitchy at all and seem great.

Maybe your right-maybe the plane stalled, but i gave it a good hand launch.

Maybe its to nose heavy

i dont know??...

[eflight-ray]

You should always do a range check with a new model, or when you change any of the electronics.

The CG should be checked, (and checked again), before a first flight.

Also check servos and control linkage to ensure there is no play/slop in the control surfaces. The control surfaces should always return to the same neutral position.

Once you have confidence that the model works correct, then you consider how your going to launch and fly it. And that's a whole new bag of worms.

[JetPlaneFlyer]

'Twitching servo' is very rarely caused by the servo itself, it's more often due to poor radio reception and/or interference.What radio gear are you using, and as suggested previously did you do a range check (with and without motor running)?

If first time it flew 'ok' apart from the twitching servos then providing all you did was change the servos it's unlikely to be a CG problem..

I assume you did check that after changing the servos the control surfaces still moved in the right direction?

Steve

[sam94]

Originally Posted by JetPlaneFlyer

'Twitching servo' is very rarely caused by the servo itself, it's more often due to poor radio reception and/or interference.What radio gear are you using, and as suggested previously did you do a range check (with and without motor running)?

If first time it flew 'ok' apart from the twitching servos then providing all you did was change the servos it's unlikely to be a CG problem..

I assume you did check that after changing the servos the control surfaces still moved in the right direction?

Steve

Im using spektrum 2.4ghz tx and rx

Sadly i didnt do a range check

and once i had changed the servos the control surfaces were all moving correctly.

[Cyclops]

I had a definately buzzing servo. buzzed with nothing connected. Put in a same type. Fine. Hooked up linkage, works. CRASH !!

I forgot to put the rod into the right hole!! 2 really super barrell rolls into the ground.