Hi All,

I was flying my CX2 and struck some window curtains. The rotor blades stalled for a few seconds before I could throttle back. Now, when I try to take-off, the CX2 will not lift-off, and instead yaws wildly to the left on the ground regardless of any rudder input. The rotors even have a different sound to them at full RPM, like they are out-of-sync? This happens even with a full battery. OK, I guess something has failed, but what??

Thanks,

John

Check both inner and outer shafts, they are probably bent and binding....... Also look at the flybar and make sure it is straight and tracking parralell to the upper blades......... Blade tracking should be looked at as well as swash being level. That should get ya started, post back when you have checked those things.


__________________________________________________ __________________________________


Of all the things I ever lost............................................. I miss my mind the most!

Check the collar on the bottom that holds the gear to the inner shaft and make sure its on the flats of the inner shaft

Based on your description I'd say check the bind of the servos. But then I'm sure you do a full checkup on these each time you fly right . Check out Eflites site for the CX or read your manual.

Sorry this is a blanket email I usually send to anyone with CX/2 problems. Some of the other things are valid such as checking flybar, swashplate etc.. as Arrow said. Could also be a battery issue.

Could also be:
Readjust your proportional
In aluminum parts - Lower head is 2 pieces not 1, make sure both pieces are tightly screwed in
Make sure swash is level when you turn on RX and Tx.
I noticed that the plastic from the tail sometime limits the movement of my right servo, make sure it's not binding. A tail boom will also fix this issue.
make sure the pitch connector on the top is not too tight or loose. One blade will pitch up and the other will pitch down causing some funky spin.
make sure flybar is straight ^ will cause same thing
check speed of both motors see if you can see one spinning faster/slower, they should begin spinning @ approximately the same time
Check the movement of the top head, if it lifts at all when you hold the flybar you might tighten this
check center of gravity, could be off pushing it left then bouncing back right etc...
probably not blade balance but could be heat issues
backwash from your blades bouncing off walls
Battery could be low (very dangerous for battery, make sure you don't fully discharge Lipos, I had 1 go dead by just leaving it on overnight in the heli. dead. No worky, $30.
Oh yeah and check the holder on the bottom gear, make sure it's on the flat part of the shaft.

Most people have problems with nose going right not left. Try starting your bird with rudder trim (left, under stick) to hard right when you turn on the motor, then it may initialize this as "center" giving you more nose left trim options. I'd say first check the pot then this.

I am concerned that you mentioned the blades stalled "for a few seconds" while the motors were under power. This could damage the 4-in-1 electronics. In fact, if under full power, it often doesn't even take a few seconds to fry the 4-in-1. I hope this isn't the case in your situation... replacement is expensive.

Hi Guys,

Yeah, I was concerned about a fried 4-in-1 as well, but I figured if both rotors were turning that was probably not it! Anyway, the problem turned out to simply be a couple of loose set screws on the collar for the lower drive gear. I removed the gear, inspected the shaft, reassembled everything, and off I went!

Thanks for all the suggestions! Not everything was applicable to this event, but perhaps they will help me the next time!

John

so glad to hear that it was a just a couple of set screws. my first thought was a fried 4 n 1.

You were lucky. A similar incident toasted my 4-in-1...