I can't figure out my 103D!

[N111KX]

I am about to dump it. I bought it about 3 months ago and the build was great and it flew 3 or flights beautifully. Then, I had a hard uncommanded piro and as it flew overhead uncontrollably I saw that the gyro was hanging from it's wires! My bad. The resulting crash began the first of five rebuilds. Since then I have not been able to get it under control. I lift off, try a couple of hovering turns then it goes nuts. It piros both directions and the cyclic seems affected as it seems to pitch and roll a bit before augering in. I first thought that it was my new, fancy PCM receiver (Hitec QPCM 7) that locked out. I then swapped out a trusty Berg and I still can't keep it in the air. The gyro and t/r servo (401 and 9254) have been sent to Futaba 3 times. I have been sent two new gyros and one repaired and one new 9254. The last crash had a brand new one of each. All settings were correct with regards to direction and heading hold was on. Transmitter is a Hitec Optic 6 that has worked perfectly with 100+ flights on my T Rex SE with a similar receiver. The only clue here may be a pinging sound that comes from the heli that sounds like the belt is slapping the inside of the boom. On the last flight I made sure that my belt was pretty tight in order to cancel this idea. There was a slight ping before it went in on the 10 second flight. My only other guess is that perhaps a bearing is bad that may be grabbing the tail drive somewhere and causing the sound. Any ideas or would you like to buy it?

Set up...
-103D
-Jazz 55
-Hacker C50 15XL
-TP 5S 6000
-Berg 7 and Hitec QPCM 7
-UBEC and NiMH packs tried

Thanks,
Kip

[mudbogger2]

Kip,
have you grounded the boom to make sure it is not static discharge from the belt?

Are you possibly using the same whip antenna on both rx's? (I have seen it done before )

Also a bad tail bearing may cause some pretty wierd tail stuff but I don't think it would affect the cyclic. :?

[jamesotron99]

You didn't damange the belt (missing teeth etc?) how about bent output shafts?

Sounds like a static discharge to me too, though. I agree with Jon, ground the boom and see if that fixes it.

[jamesotron99]

...one more thing, try mounting it on a turntable or something for testing so that you don't have to rebuild it every time.

[N111KX]

Thanks for ideas, gents. The static electricity idea seems like it has a humid environment and very short flight time going against it. I like Deans antennas and have used three different ones in two different locations (on the boom and on the skids). Seems that the belt was in good shape. Now, let me see if I can find a turntable

PS, looks like the Lepton is up and running, Jon...!

Kip

[gordohigh]

I have had my tail whip around with a static charge letting loose, but it only last for a second or 2. Very well could be that. Also, I had a pro help me in my final setup. Really gave me peace of mind knowing I didn't forget anything because these parts are expensive.

One mistake I made early on, forgot to extend the antenna, (DOA!). Resulted in a crash against a chain link fence, and new blades shaft feathering shaft, flybar, you know, the usual. I had just finished flying my trex with the spektrum DX6 with the stubby antenna. Won't ever do that again.

Another thing I noticed, the tail belt must be pretty tight or you will hear it slapping the inside of the tail boom. Also, make sure your antenna wire is not tied to any carbon.. Ive used the deans antenna on all my logos, and had no problems in that regard, and use pcm on 1 and ppm on the other 2 with good luck on both.

Don't give up, get a buddy or a local club member to brainstorm ideas with you, you will eventually figure it out.... good luck!!

[OICU812]

Easiest way to see if it was static related inconcern with the belt is to apply some "super O' Lube". It is a silicone based, thin anti static type lubricant. It adheses to the belt awesome and does not attract dirt and gets rid of any static from the turning, rubbing etc.... I re apply after every 50th flight or so and I am good. No need to grind, sand or anything in regards to boom grounding needed. I run the cf frames and cf booms etc with no issues. I also ensure to put the antenna wire in a peice of vacuum tubing to isolate it from touching any frame or cf components, this has been a solid way to deal with these issues from my findings. Let us know how you make out and if we can be of more assistance in the matter, good luck! :mrgreen:

[MrMel]

Dont know if that is the case, but do those two receivers you have use different chrystals? If you use the same, that could certainly be the cause as well, they dont always hold up in crashes.