[RICHARD PAINE]

While readying my new Brian Taylor ME 109 E for its first flight, the ailerons did not work, The aircraft uses a Futaba 617 Faast receiver & a Y harness to activate the two servos in the wing, All the other servos worked properly.
I carefully removed the wing, trying to catch the problem in the act, I plugged a separate servo in the aileron connection on the receiver & it worked, I plugged the y harness back in & no ailerons.
It had to be a connection problem in the y harness , or so I thought. Then the ailerons started working with the original Y harness.
I changed out the Y harness but I am still concerned, I opened up the original harness & found nothing. I lifted the locks on the Y harness & pulled out each wire to ensure they were crimped properly, nothing ,
When setting up the radio during the build, one aileron started to cycle back & forth on its own, I replaced that servo.
Is it possible the long leads out to the wing servos can cause the receiver to be the problem in trying to run two servos on long leads ??
I have since changed out the receiver also.
any thoughts ??

[hitechflyer]

I find some servos don't like to be ganged up with a Y harness, did you try one servo at a time using the Y harness?

[bbbair]

First Off;
I applaud your testing of your equipment BEFORE getting to the field. Well done!

The problem you are describing could be caused by many things.
I would, start by cycling the battery to ensure that it is fully charged.
Then Rebind the receiver to the radio.
Next - reseat the 'Y' cord in the receiver - it could have been loosen with a bump or vibration.
These are just in case something failed over the winter...

If this does not solve your issues you are on the right path by replacing the components - when all else fails replace them all with KNOWN Serviceable items and retest.

No; I have not seen the length of a wire in a model Air Craft cause a problem. Wire length usually does not have an effect until you hit lengths that are causing line loss or happen to be a harmonic of a frequency being used. (we now use digital signals and such problems have faded away)

Good Luck!

[hitechflyer]

Length of wire can definitely cause a problem!

[deaconFlyer]

Yes to everything above.

From my perspective, I regularly use model airplane cabling for extending portable LED light projects. The wires are quite inexpensive and they click-lock when connected. It is a win-win compared to other options. We use RC receivers and control the lights from RC transmitters.

That said, I can't begin to list the number of times there has been a problem with a off-the-shelf, brand-new cable. It usually has to do with a higher resistance and the issue could be anywhere ... from the connector, the crimps at the connector, even a bad wire. I have cut open cables to find the wire crimped to less that three strands of wire.

Yes ... I get power through it but the lights are dimmed compared to the one beside it. A quick check with my ohm meter often confirms the problem. Because of their use, these cables are going to go through the stresses of a model flight plus they are going to be pulled and flexed and pulled and flexed and then flexed again. We shake them like crazy when testing them.

Using quality gauge wires, the length of the wire should not be an issue with a model airplane. The condition of the actual wire internally ... plus the length ... plus if it is too small a gauge ... that can be a different thing.

Just one other observation ... it really doesn't matter whether I put out huge dollars for the wire or buy cheap ones in bulk. There seems to be the same number of failures.

Still, for the very tiny dollar value, these things are amazing ... just never trust them till you put them under pressure.

[Cougar429]

I have heard some Futaba Rx's suffered signal strength issues when using Y-extensions, but the instance I remember was referring to servoless retracts. I would think this is independent of the battery voltage.

Went looking but could not find the specific thread.

[RICHARD PAINE]

Thanks for the opinions & advice.
No I didn't get to try just one servo on the Y harness as the original set up mysteriously started to work as I was doing the process of elimination.
The replacement Y harness appears to be heavier gauge than the original & much shorter, this has to be a positive.
I use this same setup & same receivers, in my three other 120 powered TF kit warbirds, 2, P47's & a Sea Fury, no problems to date.
I have always been concerned re the size of the 617 Futaba receiver as it is Tiny!
The Futaba website info states it is good for park flyers up to giant scale.
I may purchase another Futaba Receiver other than the 617,
any suggestions ??
Thanks

[RICHARD PAINE]

I guess I am answering my own question, as I went to the Futaba site & the only current receiver suitable for this application other than the R617FS is the R6008HS. It is a more expensive 8 channel receiver.
Any thoughts ??

[hitechflyer]

If 7 channels is all you need, then what I do is use two Y harness's home made to proper length. Sharing the servo channel and to supply power to the battery twice.
For example channel 1 and 7 go to your servos using a Y harness and the other end of the Two Y's go to your battery for redundancy.
Don't worry about the size of the receiver, a 10 amp speed control takes more punishment and we all know how small they are.
I use the 7ch rec. in my 50cc size Yak with 6 high voltage digital servos.

[RICHARD PAINE]

OK, I think I have it ?? power from Ch 7 connects to the 2 wing aileron servos to provide voltage & ground from 2 sources, Ch 1 & ch 7 ?? correct??
Is the signal wire lifted from Ch 7 as to not supply a 2nd , different signal to the servos ?