NateHolmes

Ok.....I have been working on a Flight Model which had very bad instructions. I have setup my elevators with a servo on each side. Now, on side goes up while the other is down. I have a splitter on the servos so one goes to the transmitter. How do I sink so both servos are going the same directions? Thanks for the help.Nate

BobFE

Not really familiar with the model your are talking about, but try connecting the push rod to the other side of the control arm on one of the servos, or if there is only one side to the control arm, take off the control arm, turn it 180 deg, put it back on, then reattach the push rod. This seems to me to be the easy fix.

AMA 74894

My Feedback: (1)

or manually reverse one servo (requires disassembly and soldering skills)
OR
use a reversing 'Y' cord. (some manufacturers suggest NOT using a Y connector)
OR
plug one elevator servo into a spare receiver channel and slave that channel to the elevator.

specifics would help immeasurably
what airplane / radio /servos?
BobFE IS correct also, but that fix may throw the geometry out of whack

NateHolmes

Turning the servo arm is not an option.   The servos are on opposite sides, evenly spaced  ahead of the elevator wings.   I guess I am looking for an easy fix without relocating the servos or changing the elevator arms.    Any more suggestions?  

Thanks

NateHolmes

Just read your suggestion AMA 74894.    I am using a Y cord, and tried disconnecting one, reversing the elevators, thinking it would maybe change one servo, then re-plugging.   That didn't work.     How do you slave a elevator to a spare channel?    I am working with a Fly Sky 9  transmitter, and a 8ch receiver,  working on mode 2.     I understand about plugging it in......what do you do after that?  I tried that once but it did nothing.   

Thanks

NateHolmes

Model is:    http://flight-model.en.alibaba.com/p...ntrol_toy.html

AMA 74894

My Feedback: (1)

hmmmm ... I'm gonna need to look it up (Mixing is actually the more correct term than 'slaving') of course you COULD go with one elevator servo, but that means more construction...
the very short version is that with that configuration, one elevator servo needs to travel in the opposite direction than the other elevator servo...
hence the need for a reversing Y cord (it only reverses ONE servo) or other method of reversing...

AMA 74894

My Feedback: (1)

ah. easier even .. you need to set in your transmitter that the airplane has two elevator servos.

http://www.youtube.com/watch?v=893rdC0i-TU

google "Fly Sky 9 transmitter dual elevator" and you should find tons of info
hope that helps!

AMA 74894

My Feedback: (1)

using the method shown in the video above, you'll need to lose the Y cord, since each elevator servo requires it's own channel in the reciever.

NateHolmes

Wow....thanks........think that will work and just found on Hobbyking.com a servo reverser.    Just a little box installed in an extension line for the lead to the receiver!    I think I can figure it out now.    Heading to youtube to watch it!   Thanks for the help everyone!   Want to get this 330 in the air!    Looks great!

AMA 74894

My Feedback: (1)

:-)with the you tube method (programing the transmitter for dual elevator servos)
The reversing y cord is not required... you should be able to set the airplane up as is without buying anything extra ;-)

NateHolmes

Thanks AMA 74894 for you help.   Feeling better about how I set it up with dual servos, and bar to the rudder servo, instead of cables to the rudder servo!    Let you know how it flies!  

Thanks again!

JollyPopper

My Feedback: (6)

I'm not suggesting this as a fix, but I found out while doing some research on a similar flap problem, I believe it was Hitec and Futaba servos turn opposite directions. Fine one of each with similar torque and speed specifications and use a Y cord and your problem is solved.

speedracerntrixie

My Feedback: (29)

The fix would be to use the dual elevator servo mix in the TX. This way you can adjust the sub trims and end points so both servos travel the same.

AMA 74894

My Feedback: (1)

Hitec and futaba servos DO NOT natively turn in opposite directions unless the servos themselves are programmable.
(or unless you open one up and manually reverse it by swapping the wires going to the motor and to the potentiometer.)

JohnBuckner

My Feedback: (1)

Actually Jim I believe JollyPopper is quite right and Hitec servos are indeed by factory default the opposite of Futaba default rotation.

I have two airplanes that I did use this method on dedicated flaps (not flaperons). Would I use this servo brand mixing on duel elevator servos? no of course not but with true flaps it works fine.

The problem using a duel elevator mix in the transmitter is if it actually is avalible in the OP's system? There are an awful lot of modern systems out there and especially the direct china stuff that does not. Of course if available it would be the best solution.

Another solution not mentioned yet is to simply use one elevator servo? Hmm what a concept, there are many way to tie two elevator haves together and has been done since the beginning of RC aircraft modeling. The only mix that would be unavalible is what is sometimes called Ailevators or tailerons and for most mere mortals those mixs are pointless. The modern push that every airplane for everyone must be a 3d masterpiece is, well is silly. This is after all the Beginners Forum.

The original method first mentioned in this thread by BobFE in the case of two servos on either side of the fuselage. Yes having the output arms one on top and the other on the bottom does work. I have serveral set up this way, One being my Wild Stick 120 (Moki 180) it works great and the separate elevator haves work evenly and together? now before I get yelled at let me explain and I only have a simple Y cord on the two servos.

They work evenly and together because I choose exactly where to mount the servos and not some Chinese dude that goes by the name Ackerman. It works simply because the pushrods are horizontal and parallel to the each other on both sides with one servo simply mounted higher up on one side. It really does work perfectly well but requires planning and most folks putting an arf together are not going go to the trouble and Arf manufacturers don,t care either and do not put the servos in the right place for this to work.

John

AMA 74894

My Feedback: (1)

I'm completely with you, John... but I completely misunderstood that OP was talking about using one futaba and one Hitec servo at the same time
(I guess I'm picky... I would never do that on elevators or ailerons ... but that's just me. )
you're absolutely right and my apologies to JollyPopper... I completely missed your point.
of course I had considered the single servo route, but since he already has the aircraft setup for dual elevator servos I didn't even add that to the equation
I also agree that dual servos (both rotating in the same direction) works when the servos are mounted offset (with the pushrod to elevator horn geometry being identical on both elevators)
I've got an Edge 540 set up exactly like that... but again since the servo's are already mounted...
I simply looked up the specs on the fly sky 9 TX and discovered it does have a dual elevator mix: simple, nothing extra to buy, adjust or fail.

NateHolmes

Interesting and very educational to read all the comments and information about the fix for my problem.      Yes, I could move the servo, but now construction involved, since there would be a hole in the fuselage. (Yes, I know....so what is the problem), but  I think the easiest, and maybe best fix is to get a: servo signal reverser, and be done with it.   Oh, the servos installed were Corona DS-339MG's digital servos, and they are very responsive and I like the way they operate and sound.  I had to install these exact size servos, or I would of had to modify all the servo installation holes!    It just amazes me that they produce these good looking models and don't include a good set of installation instructions!  

Thanks for taking the time to comment everyone......  I will post when I finally get this 330 EP 57in, up and flying!  

Nate

JohnBuckner

My Feedback: (1)

Excellent Jim and thanks for looking up the OP's system and agreed that's the best way to go. Sometimes wonder though about those systems.

Let tell a story about, well lets just call him Henry.

Henry had been flying for maybe about ten years and did OK, His system was a Futaba 9c that later on was converted to use Hitec 2.4 and Henry had quite a few Rx's. Now Henry was not real sharp about programing and such but that was never a problem as many of us helped him often with this.

Now what happens is a club member not really a flyer but very active computer geek starts selling Henry a bill of goods about some super duper china nine channel radio that he could just not live without. Well henry falls for it and buys the sixty dollar system or whatever it was and the geek helps henry program the first of his many airplanes. Henry even sold off his old stuff and all the Hitec 2.4 receivers.

So you guessed it, the geek is nowhere to be seen and Henry cannot even change the airplanes in his radio and certainly not install another and likely will never learn that. The so called instructions are written in Chinglish and of course there is no one willing invest the time in learning the system just so Henry can be cheap. This story is not that uncommon.

Henry finally had to invest in a new Hitec Eclipse Pro with a bunch more Hitec receivers and parked the china system.

John

NateHolmes

Interesting story their John, but just not sure what the story has to do with installing and solving the problem of duel servos on the elevators?  The

FS TH9X is a great transmitter for the price, and operates just a well as the $300 units. 

Jim, AMA 74894,  you mentioned you looked up the specs on the fly sky 9 TX and discovered it does have a dual elevator mix: simple, nothing extra to buy, adjust or fail.   Where was that located ? 

Thanks      

BobFE

Actually I think John was trying to express the KISS principle (Keep It Simple Stupid). The more complex you get, the harder it is to figure out. Find the simplest solution and go with that. Nate, it might be easier to understand the problem if you could post a few pics of your set up.

rlipsett

get hi tech programmable servos and the programmer. reverse the direction of one servo then match the same center and endpoints using the programmer. After this is done you can use a y connector to connect both servos to the same channel and they will be in sync

AMA 74894

My Feedback: (1)

great advice, I made an (INCORRECT) ASSUMPTION
the first time I googled 'Fly Sky 9 transmitter dual elevator'
I found all sorts of info... what I DIDN't realize was that these were all people pleading for info on how exactly to do this... :-/
I still haven't found the info in understandable English...
NateHolmes, what I was referring to was this you tube link:
http://www.youtube.com/watch?v=893rdC0i-TU
however it seems that route is for using dual elevators in a V-tail configuration...
I'm red faced now. [:@]

qldviking

Sadly the world of rc is flooded with these new youbeaut el-cheapo radio sets, and as per usual with most garbage from china the instructions, specs etc are written in chinglish. What has me seriously thinking about that issue, is how often is it poor english, and how often is it obfuscation or downright "deniable" poor translation! They use termiology that means one thing to us rc'ers, but in the instructions mean something totally different, and useless to what is needed/wanted I have a buddy who bought the same "fly-sky 9" and in reality its got no real mixing, and is pretty much useless to any people that really do need 7-9 channels with 'real' mixing. The blurb on the box is so ambiguous in its wording I'll bet it was written with a lawyer on the ad team. The bottom line is still "you gets what you pays for!" Just another point too with these el-cheapo sets, check the range specs for both Tx and Rx, usually the Rx is rated to a far shorter range!!! eg my mates set the rx was stated to have a range of 500m MAX! ergo only suitable for park flyers.

Having looked at a number of these 'el-cheepo' sets and thier instructions, I will happily stick to JR

subzJC

[] Poor Henry,

Nate, I'm no computer geek but have figured out how to mix with this radio.
Plug your second elevator servo into channel 6.
Then go to prog. mix and select mix 1.
First switch from Inh to act.
Then select elevator for the master and flap for the slave.
Next change the uprate and downrate to 100.
Finally change the "sw" to normal, then click your menu button to save.

The biggest challenge with this radio is that it can be used for helis too.
Therefore the pit and hover trims that are knobs arn't real helpful.
Channel five is for gear and six is for flaps, you can assign the remaining
channels but then you have to use these knobs. For instance I programmed
a mix for dual aileron servos by assigning channel 8 for pit trim and then
setting the mix but the knob could get bumped during flight and throw
the trim off. Give the flap mix a try and if you have more questions I can try to
help.

Good luck