I'm not sure this is the correct place for this, but here goes. I bought a lot of equipment from a gentleman no longer interested in RC. Among the stuff is an airplane that I believe is a Kadet Senior. At any rate, it has no ailerons. I want to add ailerons, which is in itself no big deal. My question concerns any other changes necessary when I do add the ailerons. Do I need to change wing incidence, center of gravity, etc. to the airplane? Any ideas will be appreciated.

wing incedence and cg does not change because of airlerons.what is the wing span and how much dihedral is at the raised tip with one wing laying flat?ruidder is more effective with more dihefral airlerons are less effective.also with flat bottom wings as used on the kadet airleron differential is needed to reduce adverse yaw,in other words airlerons should move up about twice as much as they move down.

That is a kit-built Kadet Sr. if it has no ailerons. The ARF has ailerons. The only thing I'd do, other than the work modifying the wing for the ailerons, is to remove most of the dihedral. This one has a lot to make rudder-only turns easier, and the plane more inherently stable. You don't need all that if you have the ailerons to help in the turns, etc.

Do you plan to make barn door ailerons (like the ARF) or do strip ailerons. I'd recommend the extra work to make barn doors, use two servos. The barn door type will have less tendencies for adverse yaw than strip ailerons.

This is a good size wing. Measured at the main spar, it is a shade under 77" with a 16" constant chord. There is a ton of dihedral in it measuring just over 8 1/2" at the top of the main spar. I'm not sure what that translates to in degrees, but it is a bunch. How much of that should I take out when installing ailerons? I was planning to put strip ailerons on it since it is just a trainer and strip ailerons are so much easier to fabricate and install. However, that ain't etched in stone anywhere.
BTW, to anyone who has built one of these, did Sig not supply fiberglass cloth to be used when joining the wing halves? I see no indication of any and judging by the lack of sanding before covering on the rest of the plane, I believe if there were cloth at the center of the wing, I would be able to see it. If I take the wing apart and flatten the dihedral, I will certainly wrap the joint with cloth and epoxy or apply resin when re-joining the halves.
Thanks for the replies, guys. I appreciate it.
Max

Are you using this plane as a trainer, or do you already have experience flying other planes?

If you are fairly experienced and really want to fly it with ailerons, then yes, take out most or even all of the dihedral. You might want to leave in a little just for looks.

I haven't built a Senior, but my guess is that there is a plywood dihedral brace inside, and therefore no glass cloth. That's the way my other Sig kits have been.

If you are using it as a trainer, it will be great as is, without ailerons. Plug the rudder into the aileron position. If you have a computer radio, use aileron-rudder mixing so you can work the rudder/nosewheel off the left stick on the ground. That also gives you instant "dual rates" on rudder, by using both sticks together.

Jim

airplanes with no dihedral look like thetr wings are drooping.3-31/2" should be enough.

Jolly:


I have built and flown a Kadet Senior. I did not have ailerons and flew it as a basic 3 channel trainer. It flew great and was very docile. I had a lot of fun with it but it is massive and that flat wing provides a lot of lift. I put an O.S. 50 in it and this gave it enough power. Mykits called for a .40 engine but I believe this under powers the plane because of its massive size. If you put ailerons on, I would consider a much larger engine otherwise you will have a plane with ailerons that can't do much. To your basic question, I have heard of these planes built with ailerons with no structural modifications. Also, you may want to check with SIG as I thoought I saw them advertising an ARF with ailerons. Good luck with your build, it is a good plane to fly just for a change of pace and like every SIG kit I have made, it is a quality product.

hey guys, i just picked up 2 sr.'s at the wram show swap shop, got them both for 100 and also a older futaba radio and a OS FS-40.one of them is about 90% done and the other is about 50%(ish). my first question is that little motor enough?(i don't think so) and second i want to build one for my brother who has never flown and one for me. his i am not sure if i should leave the wing alone or put ailerons in it(the wing is built). but the one for me i want to put ailerons in and i want the barn door,can some one tell me the best way to do this? also i would like to make it a float plane, i have always wanted one and this plane seems like it would make a heck of a float plane. any help would be great!!!!! thank you

Bombingrun:

I have built the Sr. with no ailerons. I like the challenge of only rudder and elevator. The .40 size engine is meant to make this plane docile as a trainer. I personally don't think this is adequate if you already know how to fly. On my Sr. I put a O.S. .50 and that made it nice to handle.

I'm in the process of building a Senior.

On Dihedral: The kit instructions result in a dihedral of 6". Based on input from other experienced builder / fliers that love the Senior they recommend knocking it to 1" - 2". Mine is at 2".

On Ailerons: Bob Nelson (the SIG Mfg Senior guru) has recommended that when adding strip ailerons to the back of the existing kit wing add a cap to the existing trailing edge to provide some meat for the aileron hinges. I chose to model my ailerons after the ARF's. This requires re-engineering the rear spar from an upper and lower spar to a single 1" spar as the ARF uses the rear spar as the front of the aileron box for hinging. Also lengthening the wing to a full 80".

Good luck on you mods.

I chose a Senior kit as my first RC plane. Spent the next 3 months building it stock except for converting it to a taildragger. The kit included the fiberglass for the center section. My first RC flight was the maiden flight of this plane(2 firsts in one!). It has 3 channels(no ailerons) and an OS 40LA. While it's not a hotrod, it is a nice flying fun plane to take to the field. I still enjoy it immensely and like to send it up with just enough power for takeoff and to stay aloft. With a 12oz tank, I can fly easily for 35 minutes doing tons of touch n goes or just floating it around up high. To me, the Kadet Senior loves to be flown around slowly and even though it only has a .40 on it, I am throttled way back most of the time. The guys at my field like how it's set up and it's slow speed and simplicity makes it a nice change of pace after flying a few tanks thru something more "exciting". Someday, I may build another set of wings for it with less dihedral and ailerons, but if I want more performance, I usually choose to fly a different plane, anyway. Last weekend, I sat on the ground with a 5 year old in my lap and let him "fly" it around. That's fun in it's own category. Most RCers these days like lots of extra power, but to me, the Senior is in it's element when flown around in minimalistic trim. There are lots of 4 channel trainers that are faster and more responsive but I like the simple "character" of the Senior as it is. Of course, I still love to fly planes with Cox .049s on them so I'm a little different from the average modeler these days.

A guy in my club added ailerons (barn door) to a Kadet Sr. without changing anything else, and it flew well. I'm making a new wing, with barn-door ailerons, for mine, and I reduced the dihedral a lot, as suggested here by several people. The wing kit I got from Sig included some glass tape. I sheeted the bottom center section so I could use glass tape on the top and the bottom. It may not be necessary, but it can't hurt.

Yeah, my kit had no provisions for sheeting the bottom center section nor instructions to do so. Since it was my first kit, I didn't know any better. That's something I would do differently if I built another one. The included fiberglass wasn't long enough to go all the way around, either, so you'd need to source a bit more. Besides the added strength, it would make the wings easier to handle without worry of damaging the center section with your fingers.

I modified a Senior from a kit by adding barn door ailerons, removing all but 1/2" of the dihedrel, tail dragger, Saito .82. Plane flys great and will do inverted, nice rolls, hammerheads, but will not spin worth a darn. A large plane and low level aerobatics gets a lot of attention, as in the ground will reach up and get him soon! Not with the Senior.
Forgot to mention that I added bolt on wings. And here is a picture of a real clock watcher, knows when its time to stop!