Hi all,
I am building a Goldberg Tiger 2 40 size kit. I read some posts, and now want to build the wing with dual ailerson servos.
However since the manual explains only the single dervo setup, i wneed some help/pictures from you all as to how i can accomplish this.
If you can share some tips/experiences/photos it wil be awesome.
I have been thinking about this and also had a few questions :
1. Do i place the servos in the middle of the wing, and use torque rods ? Though i am not sure if the fuselage would accept the wing with 2 servos in the middle . Also i think the torque blocks are light for the big ailerons.
2. Or do i place the servos inthe middle of the wing, and use a control horm on ailerons ... for this should i mount the servo iin a sideways position ? i would like to have a minimum drag because of this mod.

Thanks all of you, i appreicate your valuable suggestions,
Regards,
Gaurav

Hi;That is a nice plane,I have the 60 version but they are a lot alike.Would say your #2 is the way to go.I prefer to mount the servos flat as can easily access the adjustements etc.On edge can't get at anything.Have had them both ways but would never intentionally put them in any way but flat!!Good Luck!!

Your # 2 is the way to go. Mount the servo's in between a couple of the ribs at about the mid point of the aileron and use control horns and a short pushrod. You can mount the servos anyway that you want to. I prefer to mount them flat so all that is sticking out of the wing is the control horn and pushrod. Good Luck, Dave

I just finished building a Tiger 2 at at the suggestion of my instructer i converted it for dual aileron servos. It is MUCH easier to just cut the hole in the middle of the wing a little bigger and install two servos right next to each other. there is plenty of room inside the fuslage . do you have your radio gear yet? just lay it out and see for yourself. place on sevo where suggested and then stick another one right next to it. i just took a dremel and widened the hole that was already there for the original set up. it literally took 5 minutes to modify it for 2 servos. Dont overenginer a simple solution. if you want i will post a picture in the morning. i am tired right now and my plane is out in the car.

Thank you all for your prompt help and suggestions !
I am considering the #2 method also, ( servos in the middle of the wing),
but Sean, i think the torque rods may not efficiently balance the aileron load during high speeds ... isnt it ? but the advantage is, that its quick fast and wont add much weight or drag.
By the way, should i consider any other modifications on this plane ? how about deefing up the landing gear parts ( i have a dry dirt ground, and expect a few rough landings too ).

Thanks a tonne for all yoru help
-Gaurav

i have never heard of the torque rods being a problem. its not an extreme speed plane so i dont think you should worry about it. i have to run out for a little while, i will post pictures when i get back

I've got a pic in my gallery of my T2 with a dual setup. I built mounts in the wing and put the servos in the center of the aileron.

I'm doing the same mod to my SIG Kavalier at the moment. Although the basic construction of the Kavalier may be different to the tiger, the principles for mounting the servos in the wing should be the same. I have some details on how i have done it in a build thread here: [link=http://www.rcuniverse.com/forum/SIG_Kavalier_Build/m_2338990/tm.htm]Kavalier Build[/link]

It really didn't turn out as difficult as i thought, just be sure to plan out exactly what you are going to do first!!

I'd have to agree with David here.

Easiest way is to glue two 1/4" square stock sticks between two ribs about 1/3rd of the way out in the wing panel. Keep the distance between the sticks at least three inches and about 3/32 of an inch below the rib and as close to the wing spar as possible. This is done so that when you glue a servo mounting plate on it will be even with the rib surface. Then find ya some 3/32" light ply and cut yourself a plate that will rest on the sticks and make contact with both the ribs. Cut a hole out in that plate to fit your servo. Save the piece removed to serve as a doubler to where your servo screws will go in to hold the servo. Now glue your servo plate in and make sure it has good contact with both ribs. You should have a pretty solid mount.

O.K. dont take this the wrong way but, how is building a servo mount in each wing(not to mention it just makes covering a bit more difficult) "easier" than just widening the servo location already provided for in the plans by 3/4 of an inch? perhaps it is better to locate servos out in the wings but it will certainly take more time. you will also have to route the servo wires plus extensions on each side wich will require making holes in each of the ribs. the other way requires no servo extentions.
by all means if there is a good reason to put the servos out in the wings please tell me- i really dont know. i am brand new to this hobby. i am certainly not trying to argue but it took me longer to type this reply than to slice the servo mount hole slightly larger in my Tiger 2.

That would work too. But you're still using the torque rods to connect to the ailerons. Reason most guys go to the outer part of the wing panels these days is to eliminate the slop or looseness of the linkage between the servo and the surface you want to control. With the servo out in the wing and a servo arm going directly to the control horn there is very little slop and if there is it's associated with the mechanics of the servo. If you were to take a look at some of the higher performance airplanes like jets, you'll see nearly all the guys flying them are using servo's with direct linkage to the flying surface. It's more out of necessity due to flutter.

With the Tiger 2, I'm sure it's okay to do what you have suggested. But if you want really tight controls with very little slop then go with what was recommended and move your servo's out into the wing.

Cheers,

If you're looking for quick and easy, then certainly the center mount/torque rod solution is the way to go.
I just decided to go with the outboard position because I wanted the shorter and tighter linkage. I also liked the challenge of doing it, but on this plane I doubt it would make $0.02 worth of difference.

[quote]ORIGINAL: tschuy

That would work too. But your still using the torque rods to connect to the ailerons. Reason most guys these days go to the outer part of the wing panels these days is to eliminate the slop or looseness of the linkage between the servo and the surface you want to control. With the servo out in the wing and a servo arm going directly to the control horn there is very little slop and if there is it's associated with the mechanics of the servo. If you were to take a look at some of the higher performance airplanes like jets, you'll see nearly all the guys flying them are using servo's with direct linkage to the flying surface. It's more out of necessity due to flutter.

With the Tiger 2, I'm sure it's okay to do what you have suggested. But if you want really tight controls with very little slop then go with what was recommended and move your servo's out into the wing.

Cheers,
[/quote

that does make sense and for a performance plane it seems like the way to go.

I don't like torque-rod driven ailerons. They are so long and narrow that they tend to not deflect as much at the far ends. If you can push them down easily with your fingers then the wind can do the same thing.

I'm not trying to scare you as they work fine and I've used them many times. I just would rather have a more positive setup. Since this is the first time you're doing this, I agree with the above advice. Mount the servos in the middle of the wing just because it's easier.

But a better way to do it is to mount the servos outboard a bit to make the whole thing more positive. I'm just splitting hairs here.

Hello all, thanks so much, do you think i should modify the landing gear to make it stronger ? or is the original setup strong enough ?
Thanks to all, i am looking forward to flying this plane asap, after reading all the good comments.
Thanks again to all
-Gaurav

Depends on your landing skills :-).

No really just add an addition plate to the rib bays where the landing gear connects too and your should be good to go...

Cheers,

Thanks Tim,
Actually our landing site is a bit rough, so i want to make sure the gear holds up.
Should i reinforce the landing gear bay ribs ? or should i reinforce the hardwood mount ?
-Gaurav

The hardwood block is plenty tough enough and the balsa ribs would let go before it would. I'd add another doubler to the ribs where the landing gear blocks are glued on. If you had some lite ply that would even be better as an additional doubler. Try to make it cover the length of the rib from spar to trailing edge as much as possible if using balsa. Remember the more surface area covered by the doubler on the rib to spread the stress, the better. if using lite ply then a piece 3/4" wide that would run from the spars to the trailing edge would be fine. 3/32" thickness of the doubler would be fine. Remember to also use the one provided with the kit. You want to add and the additional strength.

Cheer's

Hi All,
Here is what i finally did.
Firstly i chose to mount the servos in the middle of each wing, ( just because i wanted to test my skills )
For this,in the middle bay on each wing panel, i reinforced two ribs with 1/16" birch ply, from spar to the middle of the rib.
Before gluing i had cut notches for 1/4" balsa sticks. i glued this all, and put 2 balsa sticks in the notches .
Finally i made a mounting plate of the 1/16 ply and cut a hole for the servo and glued this to the balsa sticks and the ribs.
Seemd to be a very strong setup, but.....
Now i am concerned that i might have made this too heavy, unnecessarily. I have also reinforced the landing gear ribs with 1/16 ply from spar to trailing edges.

Do you think the weight can be a problem ?
Thanks for your suggestions
Gaurav

You might try cutting some lightening holes in the servo mount plates. 1/16" birch ply was a bit of an overkill. The Tiger has a lot of wing surface so I don't think you've hurt it too much. If the servo plates span the full width of the rib bay, you might try (carefully) to drill out a couple of half inch holes to lighten it up.

Hey least you'll know that you've got a very strong set of gear!!!

Cheers,

Isn't that splitting hairs? You can't be talking about more than a few tenths of an ounce close to the CG. If this was a precision 3D plane - maybe. But it's basically just a low wing trainer. I highly doubt you could ever tell the difference.

Yea you're right....

Yes, i plan to use this as alow wing trainer for aerobatics and general flying.
Guess i should leave the setup as it is , drilling holes might damage the ribs ...
I just want the plane to act the way it was designed , ie smooth and controlled.
Thanks all !

I also second the dual servos in the center using the current servo cut out. Its an easy mod and you can also allow your Tiger II to have Flaperons for a slow crawl landing speed. Right now I am using the single servo set up and its working just fine, but I have also had the ARF with the dual servos mounted outboard in the wing panels, and that was nice too. If you have a mixing radio, the flaperon feature is nice. I am curious about the Tip stall tendency that the flaperon might create though.

Aaron

My second Tiger II below:

Here is my finished tiger .. I put in the servos in the center of each wing panel, and it wokred great.
Had wonderful flights today and love the plane !
Thanks for all your help
gaurav