reversing y harness?
 

ok im useing a dx6i with my 300s extra and not sure how to get duel elevaters to work was given a great setup by another member on how to make every thing else work the way it should but stuck on the reversing y i know it has one just dont have the instructions fr it as it was already in the plane thanks for all your help and like i said im useing dx6i [&:]

RE: reversing y harness?
 

I take it the plane has dual elevator servos, one for each elevator half?

A reversing Y will be one solution. This will reverse one of the servos so that the both move the elevator in the same direction at the same time. If your linkage is not spot-on however, exactly the same on both sides, you could end up with the elevator halves moving slightly different.

Another option is to mix a spare channel with the elevator. One elevator servo gets plugged into the regular elevator spot on the receiver and the other servo gets plugged into the spare channel. You make the elevator the master and the spare channel the slave. Your linkage should still be exactly the same but you'll have a little leeway to adjust the enpoints and trim separately for each half if needed.

RE: reversing y harness?
 

Another option is to mount the servo in the wing cavity and use a pair of rods from the servo to the elevator. I use a pair of Sullivan Carbon rods fitted with the proper hardware on either end. On the servo end, I take one short length (two inches or so), sandwich that inbetween the two long rods, wrap it with cotton thread, then put several drops of thin CA on the cotton. This will solidify the whole thing into one.

Then you put a threaded rod into the short length so that you can attach that to the servo clevis, and on the other end, put the proper sized threaded rods in both ends, one on the right and one on the left then fit that with clevis'.

RE: reversing y harness?
 

Dick,
Hitech08419 is setting up a Greatplanes Patty Wagstaff 1/4 scale extra (we have been discussing this setup through PM), given the size of this plane and size of the control surfaces I think the dual servos for the elevator would be the best bet Shorter non flexible control rod is better for large counterbalanced surfaces. I read the manual for the DX6I and found nothing about a mix for dual elevator servos. If you could peruse the manual that came with yours maybe you can find something about dual elevator servos. I reccomended a Matchbox or Smartfly Equalizer2 so he could properly reverse the servo and set end points. if his radio has a dual elevator mix the reverser isn't needed, but again I couldn't find
anything in the manual.

RE: reversing y harness?
 

Since it is a 6-channel radio, maybe turn off the flap or gear switch and mix with that channel? I've done it on my DX-7.

RE: reversing y harness?
 

It may not have the ability on the dx6i, my 6ex didn't so I moved up to the 7C. I had a reversing y on my decathlon.

RE: reversing y harness?
 

I tryed a reversing Y a few years back and had nothing but problems getting the two surfaces to travel the same distance. If possible mix the two servos together with your radio. Much cleaner instalation. Good Luck, Dave

RE: reversing y harness?
 

Well, Chris, that's not what was in the OP. We are not mind readers and try to offer comments that may help such situations. NOW that I know what you guys are doing, then parhaps I can make comments and suggestions that are more applicable.

Besides, this is a beginners forum, and this does not sound like a beginners topic.

CGr.

RE: reversing y harness?
 

Well, this might be oversimplification, but if you reinstalled one of the servos facing the opposite direction and remake that control rod the proper length, that would solve your reversing problem. Then you could just use a regular servo Y connector. That's what i do for ailerons too.
Just a thought.

RE: reversing y harness?
 

Turning a servo around doesn't change the direction the output arm rotates.

RE: reversing y harness?
 

If you are going to use 2 servos that need to operate in opposite directions then get a matching set but with one of them operating in reverse. JR has their ST47 servo that does this. JSP20050 & JSP20050R servos. Throws should be equal and balanced on both sides.

RE: reversing y harness?
 

i guess what im trying to figure out is i have seen on some planes the elevators (looking from tail) and (dual servos) move up and down (for take off and landing) and during 3d flight thats is where they are split one up and one down can that be acheved on a 6 ch tx or is that just a great function on higher end more channel tx (((because when i move my elevators they both move the same up and down))) maybe thats a more clear question than what my topic is about thanks guys for all the info

RE: reversing y harness?
 

Oops, ur right bruce. I was thinking about ailerons, where the servo arms are on opposite sides...............:)

RE: reversing y harness?
 

There is a mode, not available on your radio I believe, called "tailerons" which would do what you describe. Also used on "delta wing" I believe, to a point. I've never used either so I'll let others go further on this.

RE: reversing y harness?
 

I think I've seen it called "ailevator" too.

RE: reversing y harness?
 

I had a delta wing, Ripmax Rapier, that had elevons. Is that what you mean?

Never mind. That was for planes without a "tail".

CGr.

RE: reversing y harness?
 

Can the two servos be set to push in the same direction simply by placing them on a y harness and the pushrod on the same side of the arm? If they both push and pull together then it should work. Problem may be interference with a servo next to it if there is not a lot of room.

RE: reversing y harness?
 

Yeah and I found as many of our club members have, that because the small reverses use their own on board crystal occillators, these will drift with the temperature, requiring frequent adjustments.

In turn the adjustments wear out the tiny circuit board mounted potentiometers used, causing the reversers to be unreliable.

Fortunately programmable digital servos can easily be reversed and offer a good alternative, but they should be purchased in matched pairs.

RE: reversing y harness?
 

Does this make the thought process any easier?? That picture and a 1000 words.
It has been mentioned before but if you buy a match box it can open up a whole new world for setting up a plane with a lower end TX or even a higher end TX when you run out of open slots in your RX. With your radio and a match box you could run two elevator servos with just using ch 2 and two aileron servos with just using ch 1.
I use a match box on a 30% Extra using two rudder servos in a push pull set up. I can center the servos so they don't fight each other.

RE: reversing y harness?
 

I have a bit of experience with these, start turning the pot switch until it reverses the affected servo if the wrong servo is affected you can either reverse the channel in the radio or swap the leads going into the reverser at that point you will have only limited trim adjustment on the pot switch and may have to lengthen or shorten the torque rod to get the rest of the trim you need before it reverses again and have no trim adjustment you will have to play with the pot switch a bit to see whats going on but you should be able to dial it in
without much torque rod adjustment but bear in mind not all apps need to be reversed the H-9 pawnee is an example the servos are oriented in such a way that the flap servos only require a standard "Y" FYI
If you are trying to enable the ability to turn the elevators into impromtu ailerons at the flick of a switch to work in conjunction with the ailerons it will require more channels and a fair bit of hit or miss master/slave programming between channels and switch assignment the reversing "Y is merely a "PNP" way to reverse a servo and give a modest amount of trim adjustment for the affected servo and compensate for the lack of mixable channels "ie" flaps or elevator etc

RE: reversing y harness?
 

My buddy lent me his Manual for the DX6I, Very nicely equipped radio. although the manual
leaves a bit to be desired. on page 70 in the P-mix section you can make a mix using elevator
for the master and the gear for the slave. whats nice about this radio that most sport radios don't have,
the slave trim can be set to move with the master. so even though Spektrum doesn't actually label the radio
with a Dual elevator servo mix, it can be made. The reason I said gear channel instead of aux
channel is because if you want to setup dual aileron servos you have to plug the right side into AUX1.
It does however look like the slaves center has to be adjusted manually (Big deal)


My bad as I didn't read the P-mix section of the manual when I read it online, just perused it
searching for dual elevator setup

RE: reversing y harness?
 

take a look at the pic with the two servo, take one and have the output shaft towards the front of the plane, and the other have the output shaft towards tthe tail, then you can use a reaglor y harness, just make sure you are using a matched set of servos

RE: reversing y harness?
 

Nope, I understand what you are trying to say and how you came to that conclusion but it won't work. If you flipped one servo around they'll both still be rotating the same direction and since they are on opposite sides of the fuselage they'll end up pushing the elevators in opposite directions. Not only that, let's say it did work, then you'd still have one long pushrod and one short one which would alter the geometry slightly and create unequal movement. The only way to do it is to reverse one servo. That can be with a reversing Y, a match-box or slaving a separate channel to the elevator in the radio.

RE: reversing y harness?
 

I don't understand?

If the linkage for one elevator is attached at the top of the servo arm, and another at the bottom, then the elevators will move in the same direction.

If in turn you are careful with the linkages so they end up the same effective length, then you get equal movement much like a dual heli linkage.

The key is to have each linkage "half" describing the hypotenuse of a right triangle, where the servo screw is equidistant to the hinge point.

I have my Bobcat 50 set up as described, and it works fine. There is NO fighting of the servos with each other because of dissimiliar geometry. I did not have to use TX mixing, nor waste a channel, nor use a servo reverser or matchbox.

It just looks a little weird, but that's all.

RE: reversing y harness?
 

OPjose, I understand what you are saying. That could be made to work. It would be difficult to get exact and possibly require some creative servo positioning depending on the plane to make everythign clear but it is theoretcially possible as you have obviously proven. Flipping one servo forward and one backward though will not work.