Receiver Glitches ????
Mike,
I've been having a very frustrating problem with my Aeroworks X300L Profile since day one.
In a nutshell, the controls periodically jerk. It appears that all the controls jerk at the same time. It is momentary and at no time has it ever caused me to loose control of the airplane for more than a fraction of a second -- though if it happened just as the airplane touches down on the ground or just leaves the ground during takeoff it could be disastrous.
Configuration:
1) RX SuperSlim 8 (this is the 2nd one, and it is brand new)
2) Xtal Channel 35 (this is the 2nd one, original was channel 38)
3) (4) Hitec HS-5625s, airlons and split elevator
a) Airlon pushrods carbon fiber with nylon clevis to nylon control horns. (2) 12" Cermak extensions, each control
(I used to have 1 24" extension and 1 12" extension, changed out 24" with 12")
b) Split elevator pushrods carbon fiber with metal clevis to nylon control horns., (2) 36" Cermak extensions, each control
4) (1) Hitec HS-5645, rudder, carbon fiber pushrod with nylon clevis to nylon control horn, 36" Cermak extension
5) (1) Hitec HS-425, throttle (throttle servo is mounted within wing with nyron to engine), no extension
6) Antenna is routed immediately outside the wing and connected to virtical stabilizer with T pin and short piece of fuel tubing.
7) Transmitter is Futaba 9C -- FM Module for Channel 35
8) Flying wires on tail surfaces, Sullivan kit which does have metal-to-metal connections between clevis' and connectors.
9) Moki 180 with approximately 3.5 gallons FAI fuel (not quite broken in yet)
10) Mejzlik 19x8 prop (carbon fiber prop)
11) Tru-Turn spinner
12) Generic 3500mah 6Volt RX pack with Sanyo cells through an double-pole MPI switch.
NOTE1: The wires connecting to the RX are somewhat squashed into the small space along with the RX, i.e., a lot of cross overs
of wires. The RX antenna is not intermixed with those wires though -- it is free and clear between the RX and exit point.
NOTE2: I've gone through several stages to find and eliminate the glitching problem. I reduced the extensions in the wing from
24" to 12" and twisted the wires. I switched out the used RX with a brand new one. I finally pulled the channel 38 Xtal and replaced
it with a channel 35 Xtal. Each time it looked like I might have solved the problem but each time it resurfaced. I've had this
airplane for 6 months and have yet to really fly it because of the radio problems.
NOTE3: Several days ago I switched out the Xtal and flew the airplane 3 times that day. They were 3 flights that appeared to be
glitch free -- I declared victory and marked the old Xtal for destruction. Yesterday I flew it once. I performed an engine-off range
check, well in excess of 100'. I started the engine, still no problems. I then placed my TX on the ground, antenna fully extended, in preparation to pick the airplane off the ground restraint. As soon as I placed the TX on the ground all of the controls jerked. I then performed another range check with the engine running -- no problems. I launched the airplane and flew it for a couple of minutes.
It suddenly jerked violently in the air. I carefully landed it with no problems.
NOTE4: BTW, this is one of several airplanes I have on both channel 35 and channel 38. I'm not having problems with any of the others and they are predominently Hitec flight packs with the Futaba 9C TX. With one exception -- I have a Creeks 120 Sukhoi with the same flight pack configuration as the Aeroworks. It is currently waiting on a landing gear repair and has not flown for several months, but I recall I had similar glitching problems with it. RX, servos, etc are the same for it as the Aeroworks. It however, does not have the jumbled collection of servo wires within the RX compartment.
NOTE5: Though it hasn't happened for a while, I have had to reset/reprogram the left airlon HS-5625 twice because the centering of the servo significantly changed -- about 15 degrees each time in the same direction. Both of these occurred after the airplane had been idle for over a month between flights.
YOUR THOUGHTS??? I'm looking for you to compare these symptoms to similar problems that have surfaced from other customers -- any commonality? Are there some other tests I can run to narrow down the problem area? I could switch the TX from the Futaba 9C to my Hitec Eclipse 7/Spectra if you think it might be a Futaba/Hitec incompatibility.
QUESTIONS:
1) Could the jumbled arrangement of the servo wires within the RX compartment cause a convulsive interference with ALL the control
signals? (NOTE: the antenna wire is not intermixed with the jumble)
2) Could the extra-long extensions to the tail surfaces cause a convulsive interference with ALL the control signals.
3) Based on NOTE4 and NOTE5 above, could any faulty Hitec HS-56xx servo cause this convulsive interference problem with ALL of the control signals?
4) The flying wires on the tail surfaces are the only metal-to-metal connections anywhere in the airplane. Two of those connections are farely close to the point where the RX antenna is mounted to the virtical stabilizer, but they do not touch. Could these metal-to-metal connects cause a convulsive interference problem with ALL of the control signals?
Your dilligence in analyzing this problem will be greatly appreciated. At this point I don't have a clue as to what to do short of pulling the entire flight pack and starting all over. I'm also concerned because this RX/servo configuration has become my norm for all of my larger aircraft and I have lost at least 3 airplanes in the past due to mysterious radio problems -- nothing common in any of them with the exception of Hitec RX and Hitec servos; I've moved to strict usage of double-pole switches because of those losses.