sthudson

After a couple of successful flights today, I noticed my elevators started glitching while I was warming up my engine. Turned off the engine and the problem went away. Each elevator half is on it's own channel, and each one would glitch at different times. I turned the radio off and watched them while in fail safe mode and they still glitched randomly.

Now here's why I'm really puzzled. Last weekend I noticed weird things happening while warming up the plane (engine running). I was using PCM in my JR 8103. Have used it for a couple years problem free. I noticed it mostly on the ailerons. There would be delays in their response and they would hold position. So I thought it was losing signal and going into fail safe (last position). I figured this would give me a good excuse to get a 2.4 spectrum model and new 7 ch receiver. Binding was easy, range test was great, and I had several good flights today, but then it started acting up on the elevators only. Any ideas?? Here is my setup:



BME engine with CH ignition

Ignition modified for 7.4v lipo (no regulator)

Dual 7.4 lipo batteries with 6v regulators for receiver

JR 86100 servos on all surfaces

8103 radio w/ spectrum module

Spectrum AR7000 receiver

Thanks for your help,

Scott

jetmech05

make sure the system wiriing is as for away from the igintion as possible......what kind of throttle clevis are you using on the engine? use plastic somewhere. Do you get glitches with ignition on and engine off?.....and lastly you are using 2 seperate switches 1 for the system and 1 for the ignition. hope this helps as it is a start.....

Villa

Hi sthudson
I have had similar experiences. Sometimes replacing the ON/OFF switch has corrected it. I now only use heavy duty switches with gold contacts. You could also have a bad servo.

sthudson

Thanks for the replies. There is 10-12 inches from the ignition to the rest of the wires. The throttle arm is plastic as well as the push rod. I have three total switched, two for the receiver and one for iginition. Seems to only do it while engine is running. I couldn't duplicate with ignition powered up but not running. Each elevator does it random, not at the same time so I'm pretty sure it's not the servos. It could be vibration?

Everything has been the same for two years before the problem started. I was thinking ignition or something causing more vibration, so I took it all apart today and didn't find obvious. Although I did notice that one spark plug was nice and tan, and the other very dark. Maybe an ignition problem on one cylinder? I'm going to send my ignition to CH and have it checked out. I might send the engine to BME to have it gone through as well since everything is apart and it's been a couple seasons...

Gray Beard

My Feedback: (-1)

Just had the same problem this summer, it was the switch. This was one of my own planes. Have one of my friends planes in my shop with glitching ailerons, it was a bad Y-harness. Replacing the switch cured my problems and it was an easy trace. Just unplug the battery and install it directly into the RX to bypass the switch and see if that doesn't cure your problem.