Wierd servo problem on my CX2

[BryMeister]

Hi there. I was flying my CX2 around earlier, experimenting with reducing the weight on my flybar. I noted that it was "jerking around" during flight and decided to go back to the stock flybar. The problem continued. I took the canopy off and powered it up while holding the tail. The following video shows what the aeiloron servo was doing.

http://video.google.com/videoplay?docid=6457179817347736388

No input on the aeiloron from me at all in the video. Strange thing was that it went away after I changed the LiPo pack. Strange... So do I have a servo going bad?

[carlo_the_wonder_frog]

Possibly, or perhaps a bad receiver or the craptastic transmitter is getting dirt on the stick Potentiometers.

[BryMeister]

The strange thing is that once I powered it off and changed packs, it's been fine. I have flown 4 packs through it since.

[jlharv]

Bry,
If it comes back, you can eliminate the radio as a possibility by binding your other radio to that heli. Sounds more like a receiver or a servo problem to me though. Maybe at a certain voltage it shows up. Did you run you battery lower than normal or anything like that?

I had a bad servo on my last CX2 and found it by disconnecting the motors and playing with only the servos running, then switching them, the problem moved, so I knew it was the servo that was bad. Had the problem stayed I would have known it was the recevier or the radio.

Just start swaping things around until you isolate it. Just make sure you remember where to put it all back.

[jlharv]

I don't think I clairified very well. The problem moved from the aileron ch. to the elev. ch., but stayed on the same servo. But you get the idea and the logic that I was using.

[BryMeister]

Yes, I follow you. At this point, I am leaning towards electrical interference as the cause, but I have no way of knowing now. I do not think that it was a battery problem. Once I saw what was happening, I changed batteries to a fresh pack and it still did it, but only at power. Then on the third pack, after a thorough checkout of the systems, it quit and never did it again.

[jlharv]

Do you have access to ocsiliscopes? If you do, you can hook one up to the power going into the receiver and see if the motors are causing the supply to get chopped up. Compare that to your standard motor CX2. You may be able to smooth it out a little with capacitors. Although that may not be practical if it takes too big of a cap. Or are you thinking more on the EMI side? I can't remember if these have the ferrite ring on them, if not, that would be easy to add.

Just throwing some ideas out there. But it sounds like you are pretty technical, so you have probably already thought of these yourself.

[BryMeister]

Thanks for the suggestions. I was thinking EMI myself, though it could also have been a transmitter glitch. I hope that it doesn't happen again, but if it does, I will be ready. :lol:

[Dwntyme]

Try moving the servo wire away from the right motor power leed. I see that in the video.
That servo wire is sitting right on the +wire to the motor...

[Kindling Maker]

I would have a tendency to think it was a servo, but I still havent found out why I am loosing power on my CX and it is driving me nuts short of the 3-1 that is the only thing I can figure out.

[JodyJ]

I'm having somewhat of the same problem. But I'm able to duplicate the problem by touching the cables that are zipped tied together. I'm going to call tech support to see what the problem is.

Talked to tech support and they are sending me a new servo. I can duplicate the problem more when I cut the zip tie and started to trace the leads from the servo to the spektrum and that's when it started to go crazy.

Jody J.

[BryMeister]

Thanks for that information. I'll keep an eye on it to make sure that I am not having the same problem.