alienx

I'm building my first ARF (Wattage Cessna 182) and am having a lot of trouble. It looked pretty straight forward once I got it, but it seems to be such an imperfect model I don't know what to do.

What I am having trouble with is getting everything to fit (and be straight!). I'm not sure if this is common to all models, or is mine particularly difficult. Obviously, I'm new to this, but I think I should be smart enough to handle this model.

I'll try to keep this simple and focus on one issue. After struggling to get the ailerons on and the wing halves together, it was time to mount the wing. This is so you can set the placement of the horizontal stabilizer before epoxy. But I couldn't get the wing to drop-in to the saddle very well. It is too long from front to back to fit in the recess in the fuselage. You can see it here with the left arrow (the right arrow shows another issue. That is, the ends of the ailerons don't both line up with the trailing edge of the wing at the same time. Only one end will line up at any given time).



I trimmed as many places as I could see that might be causing the wing to bind, but it only just allowed me to get the wing bolts through the wing and into the fuselage. But now that I try to line up the stabilizer, it is not parallel to the wing when viewed from the front. You can see it here.



As you can see there is almost a half an inch of difference on the two ends (maybe more). The instructions say to shim it until it is level with the wing, but that doesn't seem to be enough.

So having shown these two or three problems, I guess I am asking what I should expect. Is this normal? Everything about this model seems to be so imprecise (is that a word), that I can't tell which is the cause of the problem. For example, maybe the wing is not level, but the stabilizer is. Do you know what I mean?

So, what should I do? How can I fix these problems, or which ones can I ignore if any? Obviously, I can't ignore the angle of the stabilizer, but I am hoping the other things might not have caused much more than a drift from straight and level flight.

Can anyone that has more experience than me shed some light on what I am going through? My build is on hold for now. Any advice would be a tremendous help!!

Thanks!! Andy

Brad330l

My Feedback: (1)

Andy,
just having a quick look at your model from front on it appears that you have not got any dihedral built into the wing. This will affect a lot of things one of which is how the wing sits/fits onto the fuselage.
Not being familiar with the model i could be way wrong but revisit your instructions and check that Mate.

Best and easiest way to for you to line up your wings etc is to set model on it's undercarrage on your bench and make sure it is sitting nice and level from the front. Now put wing on in center and measure wing tips to bench and shim if required to even up. fix wing to fuse and now do the same for the horizontal stab and the fin.

As long as it looks right it should fly right. Models do need shimming and trimming. It might be an inch different at the end but this could equate to maybe only a tiny shim to fix it. Just work through and you will be fine.

HTH

Brad

alienx

Yea, the wing in almost anti-dyhedral if that makes any sense. It's perfectly flat , but with the flattish bottom surface, it almost looks like it bends down. It's just an illusion though. Anyway, you did give me one good idea. That is to try to see it the wingtips are level to the table. Then I can see if I need to work more on the wing, or try to shim the tail. I swear, no matter what two surfaces or pieces or acnhor points I try to look at, none are level to eachother!

I'm trying to be patient with this thing. I've already figured out that there probably isn't going to be the perfect model. And my desire to have a nice Cessna may have to wait a while. Maybe this model will end up being a sort of $70 Frankenstein of sorts! And then I can learn from it and buy a different Cessna down the road a little bit.

Thanks for taking a look!!!

flyinrain

My Feedback: (25)

ARFs can certainly be of poor quality and take work to make them right. I think the dihedral is fine and not the problem. It is hard to see how far off the wing is from fitting in the saddle. Would the wing mounting screw align up? Is there suppose to be rubber installed between the saddle and wing to fill in the gap? The aileron problem does look far enough off to be a problem. The only way I can see to fix that is try to bend the ailerons until it matches. Be very carefull in that if you do this not to break them. The wing and stabilizer alignment does happen and you will need to sand the saddle of one or the other to get it to match.

alienx

I know the dihedral isn't a problem per se. The wing is pretty straight (by design). The wing screws were tough to get aligned, given the other fitment issues of the wing. What is nagging me is that it is only about 1/8" up in the back, but it is up because the trailing edge is extending just past the back of the saddle, and resting on the back of the fuselage. It's hard to see in the pic because the offending side is on the other side of the picture. The two wing halves are about 1/32" or so from being even at the trailing edge.

I guess I can sand the back a little. It shouldn't take more than a 1/16" notch or so to get it to sit down. Then I can see what else may be off. I guess I could try to shim the wing (which will be easier and hidden). But it sounds like I first have to commit to getting it in the saddle cleanly.

Thanks for the suggestions. I guess you really do have to shave and sand and cut and bend a little to make these things work. I'll have another go at it tomorrow (or maybe when I'm rested next weekend. Not giving up yet!

Thanks for the help.

Stickbuilder

Look closely at photo #2 It appears that the entire fuse is twisted. Looking at the firewall, it appears to have a clockwise twist, ant the empennage appears to have a counter clockwise twist. and obviously the wing saddle needs attention. Does the other aileron have the same problem, or is this just seen on the right side? The ailerons appear to be covered in some kind or semi-rigid plastic, so maybe remove them from the wing and try steaming them and inducing a twist until they are straight? I dunno, this is why I try to avoid all ARF's I had rather correct my own screw-ups than work on Joe Nguen's.

alienx

You are exactly correct (as far as I can tell). The airframe is glued inside the fuselage (all plastic), and it is either slightly off, or what I thought, there is a twist like you said. You are right about the ailerons too. They both have the same twist (maybe in opposite directions??).

I'm actually going to see if Wattage has any advice before I get too deep. I hate to have to keep correcting things every inch of the way. Bt then again maybe this is the best you can hope for!?

Thanks!

Brad330l

My Feedback: (1)

If you can set your ailerons up so that the inboard of them is flush with the wing and the tips are up a little then just go with that.
It will just be like washout to the tip and will if anything help your slow speed flight.

What is the wing and aileron covered with?
It looks like shrink film of some sort,,,, Well the wing any way,,,,,so carefully twist the aileron in the direction it needs to go and apply some heat with an iron (clothes type or covering iron if you have one) very lightly and heat up the covering where it gets a bit loose. This should take out a small twist/warp.

Warning!!!!!! Hold the iron just off the covering and start cool and work up to a bit warmer till you can see the covering tighten.

Sorry i dont know how much you know and wish i was there to hepl.

Best of luck alienx

Brad

alienx

Thanks Brad. The wing is as you described. It is one of the particular film coverings over balsa.The ailerons themselves seem to simply be balsa with a paper glued over to give it that ribbed look of the real cessna.

Here are some more thoughts. I looked at this thing again this morning on my way out the door. The ailerons seem to be straight when I look down the trailing edge. The center section of the trailing edge of the wing seems to be the offending section. At least one side is definitely twisted (or curved down actually). This I may or may not be able to fix with a hair dyer. That is, I noticed that if I bent it straight, it put wrinkles in the skin. So I am guessing I can heat those out and it may actually hold the edge of the wing straight(er). And the ailerons also seemed to be pretty flat when they were lying on the work surface before I glued them. But I didn't go looking for warp either.

The thing that seems to be the biggest problem is the whole model seems to be unsquare. I imaging the wing and tail have to be square, but there really doesn't seem to be any good starting point. That is, the saddle seems to be crooked to the frame, the saddle and frame seem to be crooked to tail, and so on.

Like I said, I am going to call Wattage today and see if they can offer any help. I am going to try all the things you suggested (especially checking to see if the ailerons will work as you suggested). Then, I am not sure what I will do. One step at a time I guess.

I too wish I had access to you to check this thing out. That would be a really big help I'm sure. At least i would know if I am supposed to keep going with this thing, or if it will end up being a $70 pile of scrap wood and small parts!!

Thanks again for the suggestions!

Andy

alienx

Well, I spoke with an understanding gentleman at Wattage and he agreed to send me a new wing or fuselage. I opted for the fuselage, because that seems to be the part that is twisted (the worst anyway). I'm going to try to be a little more forceful with it tonight and see if I can get close with shims. And then I'm going to see how I can do with the wing edge warp and a little heat.

Thanks for all the help. Stay tuned!


PS. If you have any other ideas, please keep them coming.

Stickbuilder

I can't believe that there are no modelers in your part of New Jersey. That area used to be ( well in the 50's anyway) a hotbed of model airplane enthusiasts. Could be that they are all either dead, or have like me, moved to Florida. Do you have a local Hobby Shop? I'll bet that there are some of us, "Old Timers" that can help get you on the right track. (No Troll intended here so don't even start) I don't think that you will find the level of expertise that you need from those of us who have only done ARF's. You need the help of someone who understands Aircraft structures. Find an old guy (yeah like me) who is retired, or semi-retired, and let him get his teeth (if he still has any) into this. I feel that this may be your best out. At least since as you have said that you don't want to trash the entire project, you could build a new friendship, and learn a completely new facet of this hobby.
Bill

alienx

It's funny you say that. My dad probably planted this seed in me. He used to build balsa kits and always wanted to fly them (but never got there). He used to take us to Thompson Park in Jamesburg to watch the RC planes. My parents retired to The Villages!!! Pretty funny huh!?

To answer your question, my town hobby shop closed about the time I bought my first 3 channel (2 months ago). I've passed that shop for 8 years and never went in. The day I crashed my Cub, I went to buy parts and they had just closed the doors. No biggy though. There aren't any other shops withing 20 miles or so. But I found a place in NYC that I can hit on the way to or from work. I can get parts there, but like everything else in the city, it's not a great place to "bond."

I looked at the model again this morning. The trailing edge of the wing can be bent straight, and I think a little heat may hold it there. And the ailerons are both out of alignment so to speak, in the same direction (or symetrically). So whatever impact they will have on flight, they should cancel eachother out. Once I get the new fuselage, I will see if that is better. If so, I will work with that and straigthen everything else as best I can. Then I am going to fly it. If it crashes, so be it. I think by that time I will have learned a lot of what to look out for, a little about how to fix it, and I will move on to something else to fly. But maybe it will fly well enough, or even good, so that I can keep flying it (and move on to something else new to fly!!).

Incidentally, I've thought about getting another "easier" plane to build so I can get in the air. But I have to believe that they are all going to come with challenges built in, so I am actually thinking about seeing this Cessna through first. I hate to keep running out and buying a bunch of parts and a plane and having two or three of them lying around because I can't finish them. At least, that's what I imagine might have happened.

Stay tuned!!

suitcase

My Feedback: (1)

Alienx, if you could see my 540 edge electric you would wonder how it even flys. It quite possibly is the worst looking thing you've ever seen.

alienx

I'd like very much to see it. Can you post a pic of the "odd" parts? Sounds hopeful anyway. I guess you are saying it actually flys in spite of some "issues!"

PacificNWSkyPilot

My Feedback: (19)

Alienx,

I've been reading along here and I've noticed that although you're encountering some frustrating stuff that you've kept your head and tried to be logical. That's great, it makes a real difference when you're dealing with tough building problems.

Now, from me, here goes; You won't believe how twisted up a model can be and still fly halfway decent. Here's what I usually shoot for with mine. I set the model level so that my horizontal stabs are level side-to-side and front-to-back. I use one or two el-cheapo torpedo levels for this as long as it's not a built-up airfoil on the horizontal stabs. Then I use the robart or comparable incidence level to check where my wing is, and on most models I simply zero them to each other front-to-back at first. Most models will fly well with that. Then I visually walk around the model and if the wing is tilted I see what I can do to reduce that tilt or remove it. You can file down the wing saddle a little at a time until you're pretty close. Keep making sure the rear is still level and that the wing is still in synch with the rear for incidence (front to back) while you carve away. I've even reset my whole wing using Sig Epox-o-Lite and wax paper when the job looked too difficult for carving. Then I had a custom wing saddle and all I had to do was smooth out the Epox-o-lite afterward. Other guys use foam with a sticky edge to tilt the wing a bit, there are lots of ways to do it, just use your imagination. This also gives you the opportunity to make the much-loved trip to the hobby shop for stuff!

Jim

alienx

Hey, thanks for the encouragement Jim!

I guess you are right about reshaping the saddle (good ideas too!). I really just want to get the new fuselage first to see if that is any help. If not, then I'm going to shave the back of the wing to get it to drop into the saddle. Then one of two things will have to happen. I'll have to shim the wing, or shim the tail (or both!). But it should be nice to get it in the saddle completely and actually see how bad it is then. Hopefully, it will at least give me a solid mount to adjust other things in relation to.

I just hope Wattage doesn't forget me for too long. I thought the hard part was going to be gluing thins before the glue cured. This warping thing was something I didn't even consider!

PacificNWSkyPilot

My Feedback: (19)

Shave the wing saddle (the part of the fuse where the wing rests), not the wing itself.
Jim

Brad330l

My Feedback: (1)

Hi aleinx,,,
hopefully you can see that you are not alone here and many of us have gone through the 'not so square model' before.


Brad

Stickbuilder

I can't believe that I'm going to say this, (at least not in a Dadratted ARF Forum), but, I've even stick built (yeah, it was years ago) some models that ended up with an out-of-square situation. (I really hate to admit this next statement ) Mainer Jim is correct. As long as the wing and stab and fin are in correct relationship to each other, (both in square and with the incidence in plane) the fuselage is kinda=sorta just along for the ride. That Cessna will in all probability fly pretty well. Do you have any idea of what the finished weight will be? I would be a little cautious of that, but there again, I have even less experience with those $$##@@ electric planes than I do with the $$##@@** ARF types.

PacificNWSkyPilot

My Feedback: (19)

Thanks, balsabandit, I appreciate the good words and the effort they took!

Alienx, I left out one small part of my overall alignment process. I take a pin and stick it in the very back of the vertical fin, and tie a string to it with even lengths hanging off of it. Use these to stretch out to the wing. I usually use the outer aileron pocket edge to measure to. Now, using any find of pen or thin marker, mark the string where it touches the edge of the aileron pocket. Once both are done, stretch the two strings straight backward and see where the marks are in relation to each other. Figuring that you're pulling them back towards you, the string with the mark closest to you means that the wingtip which that one correlates to is pushed forward some, and the other wingtip of course is pushed back. The idea is that once they are the same distance from that pin then that wing should be pretty square to the fuselage.
This of course doesn't account for a thousand little variables like twisted, nasty fuselages from the factory and things like that. When it looks crooked no matter how much your string says it is straight, then you have to decide yourself. The end result being that it's still probably going to fly pretty well as long as you got it pretty close on all the other alignments.

The BEST alignment advice I can give is that you should stop into the forums and check out any new plane you are considering. If it's been out more than two months I guarantee you that there are posts related to the building and whatever cussing had to be done during that building! That can give you a heads-up on potential problems. For instance, last year I fell in love with that Sig Sun Dancer ARF Bipe, but I didn't know how good it was. I went out there into the forums and found out that it had been pretty well recieved but that some top wings had been popping off! There was enough wing area in the lower wing that most of them had been able to make a good landing ( Good=didn't crash and burn, made it down alive!) Turns out some early hardware had been failing but I also found out that Sig had rectified it and was sending out upgraded hardware for that part to the guys who already had one (who requested it) and of course was including the upgraded hardware in the new Sun Dancers. I found guys that complained that the paints didn't match from the fuse to the cowl. I looked at mine and could not see any difference no matter how hard I looked.

It's all what you make of it. I notice that nobody actually asked you if this is your first plane to fly, but I gather that it probably is. If it is, give it a rest and go and get yourself an ARF trainer, because although a Cessna is not a particularly hard plane to fly, it is not a trainer by any stretch of the imagination. It's important that you start out with a trainer, they are forgiving of the mistakes that every new flyer makes. If you're already flying, then just ignore me, I go away eventually!

Jim

alienx

Thanks fellas.

The auw is about 24-28 (I think). But I am going brushless and with Lipo so it should be mid to low end of that I guess.

I was going to shave the back of the wing because that is what is hanging up on the notch in the fuselage. I was hoping to get it to drop into the saddle all the way and then I would be able to see if the level was off. You know, kind of get it true to the saddle as it is, and then see what would be easiest to fix, the wing or the tail. I guess I could shave the front of the saddle too, btu I don't know if I could get the 1/16" i'm looking for without compromising the integrity.

You are right about this being my first 4 channel. I originally just wanted to build it just to have a Cessna, and I would fly it later on. But I've put so many hours on the simulator in the past couple weeks, that I am fully ready to see if I can fly it. Obviously, the sim is not real, but I am amazed at how close it feels to the characteristics of the plane I have flown. And also, I remember how thumb stupid I was the first couple hours. I could hardly fly a slow and level pattern around the airport. Now I spend most of my time about 6 feet off the runway, in tight spaces. I have to believe that that will be a big help (combined with my limited real-world flight on the cub).

I go on vacation to NoCal on the 11th. I am going to try to get out to a local field or some shops while I'm there. Hopefully, I will have the new fuselage before then so I can get back to work on it. Iam definitely anxious to see if it is better then the current one. The other thing I realized too recently is that the slots in the tail have a fair amount of play in them. Even though the edges of the openings touch the stabilizers, the inside of the openings widen out towards the fuselage. So I am pretty sure I can get a fair amount of shim in there. Maybe that would be enough to straighten it out. But again, I am going to see if the new fuselage is any better before I commit to any other adjustments.

Thanks again everyone for the advice!

PacificNWSkyPilot

My Feedback: (19)

Sounds like you're thinking ahead on things. Likewise, I'd recommend that you not shave anything that you'll be keeping until you're sure it'll need to be shaved on the new fuse. I agree, if you have a lot of play in your tailfeathers you could setup the wing at zero and then follow suit with them....it's the other way around but by no means a wrong move.....as Larry the cable guy says...."Git 'er done!".

Keep flying that flight simulator, crash 'em by the hundreds, and especially crash them while landing. Find out what works near the ground and what does not work near the ground. Land 'em fast, land 'em slow. Go to any field and see where the guys have the most trouble.....it's ALWAYS in their landings. They haven't learned how to bleed off speed, or how to deadstick land. Guys panic left and right when somebody calls out "I'm deadstick!". Deadstick is a real breeze, you just have to learn how to take what you have and make it into a successful landing. Also, bring up that nose just a split-second before you touch onto the ground, makes all the difference. Practice, practice, practice. That's what it takes to make average flyers into great flyers. Simulators give you the chance to make the expensive mistakes a hundred times over and learn why it happened. By the way, flying inverted is a great thing to learn on the simulator and you won't see too many guys doing it at the field, because it takes practice.

Jim

Stickbuilder

Dang it Jim, Don't you go an make references to one of our local Hero's ....I resemble that remark!

PacificNWSkyPilot

My Feedback: (19)

Errr, Sorry, BB.

Does it help if I used to live in Florida over 20 years ago? Tampa/Dover/Plant City.... AHHH! I just caught that anhedral thing you put there...that's actually pretty funny! So I'll add: "Unless you fly with anhedral....then you're gonna die!".

Jim

alienx

Well, good news of sorts. I test shimmed the model last night. It took all the adverse angle out of the tail. And as I was reinstalling the wing to see if I could straighten the tail with shims, the wing actually dropped in the saddle all the way. It was tight, but at least I got a clean look at the situation with the wing all the way seated, without having to shave anything.

So I am going to stop by the hobby shop here in the city (NYC), on my way to the train tonight and buy some balsa. I want to use that for shims. With a little luck, I can get the tail on tonight so that it can dry overnight. After that, it should really start to look like a plane!!


PS. It is amazing how much better you can feel about the model when you see the tail and wing in parallel!! I guess there is a lot of psychology happening here.


PPS. Does anyone have any suggestions for a battery and prop. Like I said, the AUW is about 24-28 oz. I have a E-flite park 450 BL outrunner. The model suggests a 7x4 (I think), but the motor recommends something more like a 9 or 10x??. These seemd to be pretty different sizes. And I have no idea how you guys are figuring out the appropriate combo of watts and amps and volts and whatnot!