Skywalker Sirius very jittery

[pardonator]

Built a Sirius over the bank holiday and flew it first time yesterday. Managed 3 successful flights but it was very jittery and sensitive really bucking around, is there something that I should look at first as to what could be the cause. Compared to flying my 1900 skywalker which is super smooth.

Also you can hear the motor pulsing randomly sometimes, the only thing I can think of which might be a complete no no is I had my Rx sat on top of my ubec, bad idea?

[FPVSteve]

It's best to separate components as much as possible so I'd definitely look into that especially if your motor is pulsing (glitching?).

Other than that though just look into adjusting your control rates and adding expo until you're happy with the way it flies.

[pardonator]

Thanks Steve I'll try to spread the electronics out.
I've got some adjusting to do as the last flight I lost all control and ended up in a tree, only when I got within 50meters or so could I kill the motor. It's like I lost all radio control

[dogzilla]

So when you say jittery and sensitive, do you mean to control inputs? Or just randomly twitching?

Being super sensitive in pitch is indicative of the CG being too far back or having too much deflection on your control surface.

Sensitive in roll is usually due to excessive deflection of control surface.

Randomly "bucking" around sounds like your servos are twitching which is causing the plane to move when it shouldn't. That would only happen if you are on 35mhz, you wouldn't see that on 2.4 or UHF.

And the motor pulsing/glitching could be either the above point meaning your throttle channel is glitching or could be a bad motor/esc.

[Coyote]

Hard to say what some of it is, but CG too far back does seem to possibly be part of the problem

[pardonator]

Got a few things to go on in that case, it did fly a bit better when I put the GoPro on the front but then ended up losing all control.

The motor seems to pulse/glitch on its own, the servos I think could just be me being used to my other plane. More concerned with why it lost complete control/signal from my Radio TX. I'll move the electrics about and repair the wing and try again!