jimbow412

Have Tower Hobbies 6XM Radio.
Building a new plane. I have a servo on each wing for the ailerons and a servo in each wing for flaps. Using a Y harness the ailerons work fine. However the flaps do not work. If I put just one servo lead into the receiver for flaps it works. Have tried a different Y harness. Also if I plug the harness into the aileron slot they work..
What am I missing?
Thanks for any help.

opjose

You really are not "missing" anything.

You have several ways of dealing with this.

- Put in a servo reverser on one of the flap servo lines : $ 3.00 from Hobby King >-- Click here http://www.hobbyking.com/hobbyking/s...h=servo revers

- Put in a reversed servo on one of the flaps

- Reverse the location of the linkage on one of the flaps so that it connects to a servo arm on the OTHER side of the servo.

- Use another channel for one of the flaps & use a mix on your transmitter

I normally opt for the cheap servo reverser I gave the link for.

This unifies radio programming, keeps the linkage geometry identical, and does not require anything more expensive.

DavidAgar

My Feedback: (108)

I would just change the control arm if possible. I have used reverser's in the past and have not been happy with the results. Good Luck, Dave

jimbow412

Maybe I was not clear- Neither servo moves when hooked to Y harness for flaps. However If I plug each servo into receiver they work??

TomCrump

You may have an RX problem.

gene6029

Sounds like a faulty Y connector, assumeing you are useing the same channel to test the servo & the Y . If the servo works in the same channel that you plug the Y into & then it stops working, i'd say replace the Y connector, because the Y is really just a servo extension putting the two servos in paralell......Gene

TomCrump

But he says that the Y-harness works on a different channel. I think the problem lies elsewhere.

gene6029

Your right Tom. I missed that part. Your correct, the problem is elsewhere.....Gene

diastole

i am new to RC. I am building a Multiplex FunCub. My Tx switch for flaps is on or off. The servo throw will take the flaps to 90 degrees. I can change the degrees all the way down to 20 degrees with a combination of things. what is the optimal amount of flaps for this plane?
WIll

TomCrump

I'm not familiar with his TX, but it could be something simple as flipping a switch..

If he has a spare, it may be a good idea to try a different RX.

jetmech05

Are both servos the same? Same brand same number and all

jester_s1

diastole- It's bad etiquette on online forums to ask a different question in someone else's thread. Start your own, preferably after using the search tool to see if your question has been answered before.

jester_s1

To the OP, if we are understanding you right, you can get the servos to work in the flap channel if they are plugged in directly, and any of your servos will work with a Y harness in the aileron channel? Have you tried just plugging the known good Y harness and servos you are using for ailerons into the flap channel? That will tell you if there is an issue with your receiver or the settings in your transmitter.

TomCrump

That's OK. I seem to have missed the part where the OP says that one servo will work, using the flap channel, but not two, on a Y-harness. But, if I read it correctly, the same Y-harness works when everything is plugged into a different channel.

Thinking about it, I'd try a different receiver, just to see what happens.

Calvinman

Hi Jimbo,

Could you post some picks? It sounds like it should work but doesn't, so some pics may give us a better idea of what is happening. If what you are saying is that both flap servo's work separately on the flap channel, but not with the Y. But the flap servo's work with the same Y hooked up to the aileron slot. Then the only thing I can think of is the receiver is not putting out enough power on the flap channel?

Calvi

opjose

The one I gave the link to has been used in over 800 flights in one season without a single hiccup. Great little device and the price is right.

bbells

I have seen this happen when one servo is defective and either shorted out or drawing too much power. I would suggest trying the same setup and alternate with a different servo.

JPerrone

Whenever something is not working, there is a fault finding method that can be used. It is "replace one piece at a time and see what happens". So, you have a servo that is not working.

The #1 check should be: Connect a different servo up, see if that works. Preferably one that you have tested elsewhere and know it works.
What other pieces are there? A harness/wire?
#2 test; change out that
#3 test; change out the receiver
#4 test; change out the transmitter
#5 test; change out the battery

Never assume anything is working properly;
Never assume anything could not be causing the problem;
But start with the most likely suspects.

This works for a wide range of things, not just model airplanes

torelentless

Agree with calvinman

jimbow412

Bingo--Got it.
Although each "new" servo would work alone--neither would work connected to the Y harness. After checking and re-checking I found that one "new" servo, for whatever reason ,would not operate on the Y connector--replaced it and -Viola.
Thanks to everyone's reply.
I hear you JP, you're so right about not checking the obvious--like when a light is not on in your house you may want to check the switch. .I might add my 1st RC system was a Galloping Ghost --bought back in 1972? . Over the years, both my work and hobbies have equipped with a good understanding of electrical system and how to TS, however this one bugged me.
Still not sure why the one servo does not work on the Y. However, had I known the values I would have been able to check the resistance on each servo and I think that would have given me a clue.

Just hated to have to tear my wing apart to check and replace servo--building my 1st Giant scratch build using a new ST3500 I've had in the box for years..
Again
Thanks everyone!

JPerrone

Imagine if you had some sort of continuity fault in the y harness itself.
- The signal coming out of the receiver enters the single wire OK
- it tries to split and go out the two legs; OK so far
- it goes down the one leg with no continuity fault in that leg; that servo works OK there
- it goes down the other leg, no continuity, no signal/power, nothing happens.

But the wire LOOKS fine on the outside.

I've seen this happen in other wires, not RC aircraft, with corrosion.

Regards

jester_s1

I'd suspect the connectors before anything else. Maybe there is some corrosion or an intermittent break?

TPL33

Go with the servo reverser (a small piece of cable that goes in between the servo you want reversed and the "Y" cable). Also, I got a servo rate reducer to slow the flaps down when deployed. Works great. Got them at RC Dude.