Ken,
I didn't know of a "better way to do it. And yes i was the idiot who broke that and i was gettin eaten up by mosquitos in the garage so i came in. But how could i do it better?

Chad,
You didn't know of a better way? Didn't you look at the drawing Minnflyer made up for you? Look back to post #47 and look at the drawing. That is a very easy way of doing a wing servo. There are several other ways of doing a wing servo also. I know Bruce has said this before, I'll repeat it. Slow down and understand what you are doing before you do it. That's one great thing about having a resource like RCU, if you don't understand you can get answers before doing it.

Anyway, your problem. The mounting for the servo needs to be in one bay of the wing, the area between ribs. As I said before, it really will be better in centered in the aileron. I can't tell for sure what kind of wood you used to make that plate, but it looks like it's some pretty heavy ply. Probably adding more weight than needed. Also, get the stringer fixed. Those stringers add strength to your wing. Please don't laugh it off as an accident. Without those strength members you won't be able to do anything but watch as your plane falls out of the sky with a wing folded in half.

Ken,
I think this will have to do. It is pretty much the same as minnflyer says accept more bays... I had to do this when i took out that orignal servo box/tray. The rib broke from that stupid CA. What will this do to the wing haveing the 2 out? And bruce told me to go in that area.

You adding weight by spanning two bays. If that's the way you want it then more power to you. But please repair the broken stringer.

TAKE UR TIME! I know from expierience.. I also had a 4 star for my first kit, rushed through it, I was done in no more then a week and a half,

I still have not flown it because of fear that something will go wrong (wings fold, fuse cracks etc.) I do not want to hurt anyone so im still contemplating on wether i should take it...

Chad,

First off let me say I am not "picking on you" I am just noting my observations. Take them anyway you wish. It's usually not in my nature to be negative, but to be positive.

I have sat back now and just watched this thread for a little while. It's pretty apparent that getting you to slow down and think things through will be a major chore. That's sad because 1.) you are a decent young man, 2.) you are building a very nice and forgiving plane, 3.) Everyone here is giving you great input.

Now, if you continue to just go ahead and do whatever you feel like AFTER you asked the question, then most people will not answer you anymore and that's not good. RCU is an unbelievable source for information, use it, listen to it.

Now as far as your wing goes, that plywood plate is to big and is going to add way too much weight and you will need to do EXACTLY the same thing on the other wing just to get the lateral balance to work out. It may be similar to the recommended design, but it is not what was called for. You went with 2 bays instead of one.

Removing the stringer was not a good thing to do, next to the main spar, that is a very important structual piece. If you piece a new one in that will be not much better, this should really be one straight piece from the root to the tip.

I see no protection at this time for the servo cable. If you leave that cable like it is right now, you can count on that cable being cut into by the wood. Hence you will lose aileron control and possibly create a glitch that goes right back to the receiver and if either happens, just grab a seat and watch the crash. [:'(]

It also looks as though the balsa sheeting near the root is warped or not glued down well.

Now as far as leaving the servo "glued in" that is also not a good thing, rubber mounts or not, you just removed the reason for them. Servos are to be mounted tight, but not so tight that you crush the rubber. If you do you took away the vibration dampening and you will see that servo slowly destroy itself over time from vibrations. Gluing them in is the same as overtightening the screws going through the rubber mounts.

At this point, you still have a wing that is repairable. It's going to cost you a little bit of time and maybe a few dollars but it can be done. If you continue as you are, it will get to the point that no amount of work will make the wing do it's job correctly and at the most inconvenient time it will fail. Heck, at this point if you were to finish it the way it is, you can count on the wing folding on your first hard pull-up.

The 4* series of planes are great planes and very forgiving, but they must be built logically to fly that way. I cannot stress enough that I am not picking at you, I as well as everyone else, want to see you succeed.

If I have mentioned items that were already dealt with then please accept my apologies.

I'll get off the soapbox now...

Chad, I don't know why you are in such a hurry. This is a plane you should NOT plan on flying until near the end of the summer. You still need time on your trainer. As much as you don't want to hear it, it IS the truth. You are on a fast track to destroying the 4* on it's first flight. You are rushing the build and not understanding the various steps prior to doing them. You are also using Home Depot materials. There is a reason why LHS materials cost more, it is better(in most cases). If you have to wait another week to afford PROPER plywood, so be it. That's what I do. We all have to budget our building expenses and sometimes things have to wait until the money is there or go into debt. I don't recommend debt, it adds up in a hurry and is an evil thing. Ask your dad about the evils of debt if you don't already know.

The plane. The piece everyone is calling a "stringer" is, I believe, actually an aft spar. Your plans will actually name it. If it is a spar, it is even more structural. Either way it MUST be repaired. If it had happened near ti tip I would not have as concerned but much of the stress will be near the wing root during maneuvers. I had you place the servo in an inner bay to keep the rotational mass down. During a fast roll, there would be less energy directed on it, it could have been further out but didn't need to be. You have cut notches in the edges in of several ribs, this causes stress points in them also. Proper procedure would have been to drilled @ 1/2 holes in the center of the rib just behind the main spar in each rib. Then run a wire guide tube to the root to protect the wiring from chafing on the wood. You should have made cardboard or balsa templates of the servo trays in the wings and gotten everything fitted. Used the templates to cut mounts from 1/8 aircraft plywood from the LHS and test fitted it for final fit BEFORE and glue came near the plane. And when the glue came near the servos should have been in a box somewhere safe.
You now have a servo tray, at least 2 ribs, center sheeting, stringer/spar that need repair. All this on a NEW plane. [:@]
When I'm doing a build, there are days when I may put on just 1 or 2 pieces and spend an hour or 2 planning the next step, gathering materials/supplies for the next day.
I'm not trying to be down on you. I do want you to slow down and think things through better and do less damage in the name of progress.

Bruce,

You are correct, it is the aft spar, my bad on using the wrong name. <shrug>

Bruce,
Thanks for stepping up and commenting.

Chad,
I hope you don't think that we are all "ganging up on you", because we really aren't. You seem like a really good kid and we all want to see you succeed. Unfortunately you seem to want to do things your way right now. If you had years of experience in RC then we would all shut up and let you do it your way, but the truth is that you new to this hobby (don't worry, we were all new at one time). We are just trying to help you. We have watched your excitement on getting this 4*, it was fun for us to watch. Unfortunately we can see where you are headed. Please give my your full attention for a minute. On your current path YOU WILL CRASH THIS PLANE. I know you don't want to hear it, but it is the truth. You are making construction decisions because they are the easiest way for you to do it. Or worse yet, you do something which is wrong and you don't want to take time to fix it. This is not the way to build a plane. I know we have said it before, but I'll say it again. You need to read every step several times before you start, then dry fit everything to make sure it fits, then and only then should you start assembling. That is the only way to build a plane properly. I haven't built a 4*, but from the looks of the wing I have a pretty good idea of the construction of the wing. If I was building it I can make a safe guess that it would take me 2-4 nights (2-3 hours each night) to build the wing. Why so long? Because I lay everything out and make sure that I know exactly where everything goes before I start using glue. If I remember correctly you had the entire wing done and off the board in a hour or so.

Yes, Bruce is right, it is a auxiliary spar and not a stringer, which is even worse because it is a major structural part of the wing. If you fly like you have it constructed you are going to fold the wing on the first flight. Also, as Bruce has said, you are adding entirely too much weight on the wing with your servo mount. You need to cut that back to one bay and use lighter material.

I think Bruce said this too, but I will say it again. You need to be practicing flying when you go out, not dropping rocks from your plane. You need to have the skills down pat before you move up to your 4*, and doing "bomb drops" isn't a way to sharpen your skills. I usually recommend to my students that they use about a gallon of fuel doing nothing but touch and go landings on their trainer. I can read your mind right now, you are saying "Boring!!!!". Yeah, it may be boring but it will give you the skills to be able to land your plane in any condition without damaging it. I don't know your instructor, but right now I don't think he is doing anything good for you. He's not helping you develop your skills as a pilot. Instead it seems like he is out playing right along side you. It's the instructors job to set the training schedule, to know what you are strong in, what you are weak in, and develop training to help you along. If he isn't doing this then he is only hurting you in the long run. Yes, I may sound cold but I am just trying to get you attention. When you get in the air with your second plane is not the time to find out that you don't have the skills to fly it. trust me on this one.

Chad, please slow down on this build. You are setting yourself up for some major disappointment. None of us here want to see that. We want to see you succeed, that is why we are trying to get you to slow down and build it right.

OK, I'll chime in with my $0.02...I had a gut feeling when this started that things were going to turn out like this. But I just can't sit by and watch anymore. One of the reasons I took up this hobby was the camaraderie between people. I receive assistance all the time from people at the field, and in turn I lend assistance where possible. That's what makes this hobby special.

Anyway, the pics below are of a 4* 60 wing and the wing-mounted aileron servo. I suspect that this design will also work in the 4* 40 wing, and I believe that's what RCKen, bruce, MinnFlyer and everyone else is talking about. Sometimes a pic is worth a 1,000 words.

The first pic shows the left-hand aileron servo from the top of the wing. The servo is mounted to 2 small blocks of balsa first (using the supplied screws and grommets), then the 2 blocks are glued to the servo hatch cover (with is lite plywood - 1/16" I believe).

The second pic shows the overal position of the aileron servo in relation to the wing. It also shows my messing building area -- but that's a different story!

The third pic shows the bottom side of the wing and how the hatch is fastened to the wing. When the hatch is removed, it sits on 2 rails (one on the left side and one on the right side). These 2 rails are glued to the wing rib before putting the hatch in place. The rails provide support as well as a place to fasten the hatch cover to, as well as keeping everything nice and flush. You cover the hatch and the wing separately, so if you have trouble with a servo, you don't have to cut the covering to access it. Also shown in this pic is the paper servo lead tube in which you run the servo wire back to the fuselage.

The fourth pic shows what I described in the third pic about how the servo is mounted to the hatch. There is a small gap between the servo itself and the servo hatch. This gap prevents vibration of the airframe from transferring to the servo. There should be no direct contact between the servo and anything else. The job of the rubber grommets are to isolate and insulate the servo from vibration.

I hope this helps. Even though you're excited about this build, I highly suggest you heed everyone's advice and SLOW DOWN! When I first got my kit, I wanted to dive right in and start the construction. But I've taken things really slow (going on 4 months now) and have caught myself several times before I made a costly mistake. I've screwed up several times as well, but by taking extra time and going slow, you'll have a chance to catch your mistakes now before they become real evident in the air.

This is not the method Minn and I were referring to but it is a valid method of doing the job. Those of us with a few years behind us know there are many ways of doing the same basic tasks and they become a matter of preference. The method you show is excellent in thin wings too, better than mine in that type. Minn & my method would still be easily accessable if done properly.

Rubberduck,
I haven't built a 4* so your pictures have given my a gold mine of information. Looking at the picture of a good wing it shows that the spar missing in Chad's wing is even more important. I see that there are shear webs built on that rear spar. Chad, shear webs are what will give this wing support and without them I wouldn't bet you'll even get off the ground, let along any violent maneuvers later.

Ok after reading i have some questions. Sorry if these are smart elec questions but for the smart elec remarks you guys give me 24/7 you deserve it back at you

Who said i wasn't going to replace the stringer? I thought I didn't.

Why is"hobbygrade better than regular ply? I can get the same exact stuff at lowes and have used it before with No porblems. thr stuff at low i can bet is much stronger too. And yes this is too thick, but i will let you know there is no difference if you the same thickness from lowes or somewhere like it except price. Wood is wood guys.


Do I need to replace that broken rib? How do i if i do?

Chad,
Regardless of what you might think, nobody on here was ever treating you in that way. In fact I think that everybody on here has treated you with quite a bit of respect. You need to take a step back and look at what is going on. There are a lot of people on here trying to give you help. In fact, you have been asking us for help, you have posted your pictures and asked us what we thought. When we have given you advise on what do you post replys similar to this
.

Do you see from our point of view? You ask for our advise, and then when you don't like it you blow us off. We aren't on here trying to help you because we like spending long hours typing, we are trying to help a young man that looks like he's really trying to do something good. Do you think that I offered to help you because I have nothing better to do with my time? I own and run 3 businesses and I definitely have other things to do with my time. I offer here on RCU because I like to help others that are getting started in the hobby I love.

It seemed to us that you didn't want to fix it. We pointed it out and you made some excuse about why it was broke and then moved on. You never said you were going to fix it.

Sorry, but wood is not just wood. If that were true don't you think we would all be down at Lowe's buying plywood instead of the higher price ply at the hobby shop. The wood at the hobby shop is higher priced for a reason, it is better quality wood. You get stronger wood that is lighter than what you can get at Lowe's.

Once again, we are only trying to help out with our advise. We really want to see you succeed. Speaking for myself, I was really excited to see you complete the plane and fly

I really hope that you can see where we are coming from.

I'm curious...how was the ST-51 break-in? Did you have any problems with the initial startup? I'm considering upgrading my Avistar with a Super Tigre 45 at some point

Typically you will find that the plywood is made up of a number of layers (plys) of wood, hence the name plywood. The more layers for a given thickness the stronger the end product. The Quality of the wood itself is better. Do you think an Oak tree is the same as a Pine and the same as a Birch tree? That is like saying copper and steel is the same, they are both metals. LHS lite ply and reg ply is made with Birch and is the best for this usage, they also use glues in the mfg that are less susceptable to deterioation from the Nitro and oils. Why do you think the FAA doesn't let builders of homebuilt aircraft buy their materials at Home Depot and Walmart and the like? They don't like seeing dead people, too much paperwork. Go to the Sig web site, they will probably have a discussion on plywood quality. They also provide for full scale.

Second, nobody is being a smart alec with you. Mind you, at times it does take great restraint not to say some things. We've offered our help. If you don't want it, just say so.

As for the ribs. IF you still have the pieces that the ribs were orig cut from, you can use one of them for a pattern. Doing that you could cut a partial rib, hold it up against the existing rib and mark the defective rib to cut away the damaged portion. THEN CA the replacement rib section into place. Just take your time and measure and mark and cut carefully. If you only fix one rib each nite, that is progress.
Understood

You're right bruce. I went back to your's and Minn's posts and carefully re-read what was said. The method you two describe and the method I describe ARE different, but both accomplish the same thing. Like you said - there's many ways to do the same thing. I didn't want to make it sound like there was only one way to do things. I wanted to provide pictoral information. I am more of a visual person. I tend to understand things better if I can see them and see how they're laid out.

I just want to point out again that the pics and description in my post are for a 4* 60 not a 4* 40, so the wing structure is a bit different.

Rubberduck,
thanks for clearing that up. I thought you posted for a 4*40. I don't know if the shear web on the aft spar is used on the 4*40, so I will stand corrected on that part.

Ken,

From what I've read in the kit building forum, it sounds like that the 4* 40 and the 4* 60 use the same basic wing design, with 2 differences.

1) The 60 size plans call for dual aileron servos stock, so the wings are already designed to accomodate them

2) The 60 size plans call for diagonal bracing between each wing rib. The 4* 40 (and the 4* 120 for that matter) do not use these diagonal braces. This is because the person who designed the 4* 60 did not design the 40 or the 120.

That's my understanding anyway...take it for what it's worth.

I think i will take a break on this. I am getting bored and sick of worrying about it.

Motor mind, the G-51 is AMAZING. I hovered my trainer on it, but i couldn't keep it up because of that dihedral/my skills. The only thing wrong is slight hesistation from low end to high end, but that is probably my fault.

Heres a little porject me and a friend have been messing around with:

We got Foam glider hand toss planes, and put model rocket engines in them and set up a track for the wings on his roof where we then launched. It was awsome and they go about 110 and depending on how we set the track is how the altitude is. We had one go VERY fast straight and one go quite high. I have pics i might add later. (and yes it was dangerous, but we had full control over where we aimed.

ok, I have began working on covering nd hingined the tail surfaces and got the elevator done last night. I will get pictures when i get home. I was wondering, Do you think sig would possibly send my a ready to cover wing? for a small price, say 30-40 bucks? I just feel that i have screwed this one up too much.

Other than that this thing is ready to go if i just cover that wing and sheet the turtle deck.

Thanks for replies...
Chad

Here is the ARF wing:Sig p/n SIGRPWK244ARFR for $138

or wing kit : Sig p/n SIGRPBK244 for $40

as found at www.sigmfg.com

I just built my first kit. A Great Planes PT-40. I screwed the wing up while building it. I did not pay attention to the plans and got the dihedral wrong. I put the dihedral gage backward while measuring the dihedral. I was frustrated but I bought a wing kit and built it again. The mistake cost me 50$ but I learned a lesson to take my time and follow the plans. I probably could have fixed it instead of buying a new wing kit , but I am new and wanted everything to be perfect.

Chad,

I recommend the wing kit and taking your time. Practice/experiment on the damaged wing in the meantime. Figure out what you think you did wrong and how you plan to avoid doing that again.

Bruce, i think i will. I could always cover the fuse while i am waiting. I am getting Really good at covering. I might work on the wing also, who knows....

If i can get the wing like it was(ribs fixed and stringer back in, i think i will be fine.

I had one question.

Why do you mount the aileron servos sideways? Why not veritcal?

Anyways. Today i plane to Cover rudder and vertical stab. and glue and hinge everything...
should be insteresting...


And here are the aftermath pics of the foam planes The whole shown is where the wing was. The first pic is of it when we saw it.