Interesting "twitching" while in flight

[the50machine]

Hey guys,

Just got my new Walkera V120D02S and also this is one of my first CP heilcopters; lots to learn before I feel really confident with CP. I noticed an interesting thing one of the last times I took off. I idled up in normal mode, her got off of the ground and while hovering the bird essentially twitched and dropped down nearly hitting the ground and then I had to idle it up to keep it from crashing. Sometimes I don't even need to idle up it just drops and quickly comes back. Is it possible I have something binding in the gears? Doesn't happen constantly but I especially notice it when I am idling around 60%. Any thoughts?

[Thomas.Heiss]

What is twitching? Do you mean the motor power drops suddenly (on/off)?

Maybe you have a weak solder point from ESC to motor?
Try direct soldering the motor to the ESC or replace the Walkera plug with 2mm goldies (works on Spin 8000kv).


For a gear / rotor turn testing there would be multiple tests to be done (taking off motor, taking off tail, turning head rotor without tail - checking how long it turns freely, turning head rotor WITH tail)....
Too many things to explain IMHO in 1-2 sentences.

I am sure there are longer threads out there (e.g RCGRoups) or youtube videos which already explain the first steps to check mechanically in more detail.
Sorry, I do not have links to them.

Thomas