I love the MCPX BL when it works. I have found several things to look out for which will keep this heli flying the way it intended. So I will create this as a trouble shooter thread.


TAIL PROBLEMS:

Q) Tail cuts out through flight for no reason.

A) Most likely the connector plug has a fractured solder joint or the wire motor is shorting onto the casing where the wires insert into the main tail motor body. I recommend that you cut the plug and solder the wires directly. Its hard to solder the motor wires, make sure you wet the wires properly and use good heat shrink to insulate the wires from the motor body. If you do this correctly you will solve most of your tail issues.

Q) Tail does not hold or seems to waiver. If you hold the helicopter still and sp0ol it up the tail motor will start and stop every 4-5 seconds.

A) Most likely there are vibrations coming from somewhere affecting the tail gyro. Make sure the bolts in the feather shaft have not come loose and the main rotor is not spinning out of balance putting vibes through the chopper. Make sure the main shaft has not split near the head. Basically this is a vibration issue.



SERVO PROBLEMS:

Q) Servos are chattering

A) Spray a tiny bit of inox into the track of the servo. If the servo still chatters after this, then pull the servo off and replace it. you can try to clean it if you like.

Q) Helicopter suddenly locks into one position (ie one servo throws to a max position) while in flight. Happens intermittently

A) Most likely the servo needs replacing. if the plastic retainer for the servo acrew/gear is loose, then try to tighten the screws but might be better just to replace the servo.


HOVER PROBLEMS

Q) does not hold a steady hover ....
A) Assuming there are no vibes - hold heli and spool up to test. It should be quite smooth. The next most likely scenario is faulty servos. Check the plastic servo hosing over the arm position tab. It should be solid and not move up and down. Power up the heli without spooling the main blade. Move the servos slowly up and down. They should not chatter.

Q) Random direction change during flight, random power down or ESC reset.

Three issues could be causing this... A faulty servo causing shorts and the ESC to overload, and/or dirt in the gears driving the pinon gear on the servo.
The third issue is a frayed power lead causing a voltage drop and the exc to go into low battery condition.


FINDING VIBES

There are number of issues causing vibes. Using a process of elimination, you can usually find the sources quite easily.

Source Vibration Investigation Procedure

With the blades on, pull the blade grips apart.Make sure the bolts in the feather shaft have not come loose and the main rotor is not spinning out of balance putting vibes through the chopper. make sure the feather shaft has some locktite in the feather shaft retaining screws.

Remove main blades. Spool up helicopter. does the swash plate move by itself or the tail stop and start at random intervals?

IF NO: Most likely the issues is a bent feather shaft or split main shaft. Inspect and replace as necessary. Also check the bearings in the blade grips just to be sure.

IF YES: Check the main gear for dirt or contamination inside the main gear. Because of the tight mesh, a large piece of dirt caught in the motor spindle can cause vibrations. Also check the main gear for missing teeth as well.

I have also seen bent or damaged main shafts causing vibes.