raron455

My Feedback: (38)

Ok Fellas, I need your help,,
I have a giant ESM 96" B-25. I have probably about 15 flights on it now and have a problem that has me stumped. I fly with a spektrumDX-18 G2, it is a proven radio, I have been flying with it for 2 years, never any issues, and all of my other planes and turbine jets fly just as they should . My B-25 has two DLE-35 gas engines , the ignitions are controlled with a smart-fly regulated dual igntion fiber optic cut-off Ignition Cutoff, Regulated for Dual Ignition Engines , powered by a 2600 fromeco LI-ION. The receiver is a spektrum 20ch powersafe telemetry receiver. The Rudders on the B-25 are in each stab, so one servo per rudder,, they are however together with a Y-harness on a single channel. The servos are hitec HS225, they were brand new for the plane, as well as the Y-harness and extensions.


Now,,,,, Here is the problem, and it does not happen all the time, just random but when it happens its consistent and dangerous. The rudders will deflect, and go a substantial amount either direction on their own, This will only happen when the engines are running, and usually get worse as you advance the throttle as observed on the ground after landing. When the engines are not running it is rock solid, I shake and bounce the plane to see if it is a loose connection and the rudders never move, it only happens when the engines are running. I have had it happen to me a couple times in flight, forcing a fairly tense landing, the plane will yaw side to side unpredictably sometimes worse than others, once landed you can see the rudders pulse side to side, give it throttle and see it get worse, and I am not talking about the normal shake from vibration, this is alot of movement I am talking about. kill the engines, and the rudders are rock solid again. Wait for a little bit, start the plane back up, do a preflight check and the rudders dont do it, but while in flight it will happen again.

I have checked my caps and they are secure on the plugs,, my best guess is there is some kind of interference with the ignitions causing the rudder movement? but why only the rudders? and How can I be getting this interference using a fiber optic ignition kill? How can I fix this, guy at the field mentioned some kind of magnetic ring. Of course another member believes its a bad connection at the Y harness, although I always use servo safety clips. Another club member believes the rudder has "a dirty Pot" I looked at him and told him there are two rudder servos, he said probably both of them are that way, but I dont buy that idea at all. I am always learning and hoping someone can put their input or experience in on this to help me out as this is the first time I have had this kind of problem, Thanks Fellas
Ronnie Dean

All Day Dan

My Feedback: (5)

Try bypassing the kill switches. Post some images of you R/C installation, especially around the receiver and antenna or antennas. Are you using a separate battery for the receiver? Dan

Ralph White

Take a look at the ignition cable going from the plug to the ignition box. On my P-51 the landing gear would not retract or extend at higher throttle settings. I found the ignition cable had a worn spot in the metal braiding where it went thru the firewall. Replaced the ignition and gear worked perfect at all throttle settings.
Ralph

Lifer

My Feedback: (1)

Check to see if the sparkplug cap it really tight. If not, that can cause the problem you describe. I had a similar occurrence with my ailerons once. The fix was to apply a wormgear hose clamp on the cap.

Prekin

My Feedback: (19)

My friend had problems with ignition interferance. He checked all plugs, replaced switches and receivers. But the troubles still went out. The last thing what he did was the grounding of the spark cylinder. That was the solution.

Lifer

My Feedback: (1)

So are you saying he didn't ground the system when the wire was obviously there? Was there any reference to this wire in the instructions?

rcpilot 1

Lifer may have the solution I had the same problem on a dle 30cc lost a plane because of the same problem replaced the plane and started over had the same issue again the second time so I change out the ign. and solved the problem the ignition I had was not old but became defective after only a few flights.
Lary

Prekin

My Feedback: (19)

He didn´t ground it before. Only used the ferrite rings on the long cables (EL, RU servos in tails). We found only some thread about that problem and grounding.

gregandhollie

I lost a DLE 30 powered P-40 on Monday and I think it was an ignition interference issue. It affected the ailerons and throttle servo only, and control was fine again with the engine off after the crash.

Prekin

My Feedback: (19)

I had problems with ailerons and elevator servos with DLE 20 powered airplane. The friend once lost signal for a few seconds between TX and RX (Jeti Duplex)

raron455

My Feedback: (38)

Dan, I will try to get it apart and get a pic when I get a day off. Yes sir, I am using 2 flight packs for just the flight controls, and a separate pack for just the ignition.

raron455

My Feedback: (38)

I do know that the caps are on, and tight. I did not use the conical springs, I have heard that they do not make a difference, but maybe they do. I will pick up some small clamps, simple and cheap, and cant hurt anything, really wanting to figure this out, I really do love this plane,,
thanks for help on this fellas

A. J. Clark

For a test try wrapping the plug wire with aluminum foil . I had interference one time . The engine wouldn't even start with the aluminum foil on the plug wire. Changed the ignition and all was good.

Steve Collins

My Feedback: (8)

Sounds like you may need buffered leads because your long leads are picking up interference. Give Andy Low a call at:

Buffer-Amplified Extensions and Harnesses - ElectroDynamics' On-line Store Page 1 of 1

Discuss your issue with him. I am betting he has a solution.