sensei

The longitudinal axis is a reference line even if imaginary that runs the entire length of the fuselage, this line generally runs parallel with one or more longerons, and generally 90 degrees to the firewall but not always, the main thing to keep in mind is to carry this line down the fuselage with the least amount of drag angle, as the airplane would fly in a normal level flight attitude, once the line is estsblished to 0 with earth, maintain the fuselage setting and go from there setting your A of I of the wing and horizantal stabs in relationship to the fuselage incidence +, -, or 0 depending your needs.

Bob

Hossfly

O.K Jim, let's try to figure this thing out. Given that you are setting up a model airplane that will be well within the sub-sonic air space for flight. There are differences in sub-sonic, trans-sonic, and super sonic airflow, each with its own little differences. (BTW) I have several books but they are out in my barn right now and I have been very busy tonight. I spent the day as Line-Boss in a RC War Bird event, and will be doing it again tomorrow. I have worked several hours this PM making up a folder to assist a brand new AMA Contest Director to take over one of my annual Competition Fun-Fly events in Feb. 2015. After about 18 years of that event, I am about ready to take a rest. I don't really care to go out to the barn tonight, now 11:30 PM, so here is where we BE, Sir.
So let us forward to wing incidence. It is not a real problem in sub-sonic airflow. You can get away with most anything, but as you said that the horizontal stabilizer should be ZERO. Where to start? Draw a line from the center of the fuselage nose at the mid point of said nose to the mid-point of the tail section of the fuselage.
Draw a straight line parallel with the first line along where the horizontal stab center L.E. to back of the Stab again center of the thickness will be. Now you have a stab
position at ZERO incidence. That will fly and allow the airplane to do same if you do it properly.
Now if you are really all for perfect, use some stiff cardboard or some such paper and make a wing rib just like the root rib of your wing. Use this as a pattern for setting your wing at whichever incidence angle you choose. Personally a MODEL airplane does not need much of an incidence angle, but if you want it then do it. You will have adequate elevator trim to make the model think it has a positive wing incidence even if you don't, since you are not using a symmetrical wing. In the real world sub-sonic aircraft use 0 incidence for slab stabs. Many use a stab that is capable of rotating the slab leading edge for the ability to trim and such creates a lesser problem when approaching the trans-sonic range. Maybe you recall that in the later days of WW II fighters, many with conventional fixed stabs, and elevators with trim tabs had considerable problems when diving into the Trans-sonic envelope. The shock-wave could cover over the hinge line and the big machine got all upset and went the wrong way. It wasn't very nice.
In your rather slow flight envelope with a model, I dare say that you will not have that problem. Now if you have a model that calls for some incidence in the wing, so be it. Just measure the line between as you stated, make the incidence along that straight line. If that creates a need for extra down elevator, then simply add a couple degrees or maybe several degrees down-thrust of the engine. Way back in the Pattern Aerobatics competition days a symmetrical wing got 2-3 degrees up-thrust and the engine got a couple degrees down thrust. At power-up the engine is trying to pull down while the wing wants to fly up. Back to idle, the engine is NOT pulling and the wing has lesser air-flow so the couple degrees pretty much takes care of the problems. It's not so much to worry about and if you keep the Center-of-Gravity, CG, MAC, etc. in the 23-28% range, your machine will fly. Aft CG behind 32% of MAC, well I won't be there to assist you picking up the pieces.

GallopingGhostler

If there is some disagreement and the conversation is civil with examples in discussion rather than to contradict, I have no problems with that. There are a few whose whole goal in life is to create conflict, whose opinions are spoken in a manner to be far superior to others without adequate backup expressed that rather grate than clarify and help. A few I have added to the ignore list. Here in RC Universe the moderators seem to do a better job putting abusive posters on time out than others. I've unsubcribed to some threads in other forums, because of a few unpleasant posters. Life is short, and about then I realize I need a life and move on to something else like building or flying a model aeroplane.

Propworn

My Feedback: (3)

I understand Jim I just wanted you to realise that even though the gyro will hold you straight and level it may not stop you from gaining or loosing altitude. Depending on your airfoil shape airspeed will have an influence on your altitude. Mine took fine tuning to get it to fly straight and level at a given airspeed. I used my incidence meter and set the main wing at 0 degrees. I then leveled the platform for the gyro. I used the same block under the tail wheel I used to initially level the model to initiate the gyro at the field. I cut it from a piece of 2X2 balsa I had laying around. At the field I used the block under the tail wheel to hold the aircraft level while I initialised the gyro. When I flew the plane at half throttle with the gyro off then trimmed the plane for straight and level flight. Turned the gyro on and the plane wanted to climb. I kept raising the tail wheel with wood shims when I initialized the gyro until the plane did not vary much when the gyro was turned on. Unfortunately this is not a constant for this plane due to the lifting airfoil and the spring tail wheel the gyro each time will be close enough but a slight adjustment in throttle setting is needed to get the plane to fly straight and level.

Dennis

Luchnia

My Feedback: (21)

I think I finally get it. There are NO experts by the definition of expert, however there are truly some knowledgeable out there that will help and there are self-proclaimed know-it-alls that want to shine the brightest that are limited.

Thinking about bad posters and know-it-alls, I don't think I have every added anyone to RCU ignore list or even as much as reported a poster. I sort of have my own built in auto-ignore in my mind when using forums.

I rarely take any post in an electronic forum too seriously at all. I have been on the forums/chats since the days of bulletin boards and have learned a lot about this medium. For the most part people will type things in these chats/forums that they would never say in person.

VincentJ

Cant speak for all, but I think joining a local club will yield you good results. In the club that I belong to there is wealth of talent that one can learn from. All of our club members are happy to share what they know to others that are learning the ropes. Making new friends at the flying field and not being afraid to make mistakes will make your hobby so much more enjoyable...

KW_Counter

Remember, an "X" is a has been and a "spert" is a drip under pressure.

If someone has to tell you he is an expert in something, he probably isn't.
If someone has a bunch of credentials, it doesn't necessarily mean they know anything other than how to take tests.
If someone passes on the knowledge they have, they make good sense and their suggestion works - they should be listened to.
Be very careful who you listen to.

Yes, I'm cynical. It comes from experience.

Good Luck,
KW_Counter

rcmiket

There's also a HUGE difference between theory and real life experience.I know guys that have all kinds of "knowledge " but none of it works in the real world.

Mike

bjr_93tz

Yes, but picking a chemist to perform a chefs job and visa versa would suggest a flaw in the selection process even though fundamentally they do the same thing.

vertical grimmace

My Feedback: (1)

Level would actually be the Datum line in which all of the elements of the aircraft are placed. This is a straight line running the length of the fuselage. This line is what is used to measure the rigging (incidences of the airplane).

For instance -2 degrees of engine thrust is relative to the datum, + 2 degrees of wing incidence is measured from the datum, and so on.

So, it just so happens that most modern IMAC type aerobatic planes have the datum line parallel with the top of the fuselage hatch.

I think that you may be over thinking this though. Just "Eye" level your plane before initiating your gyro, and that should be close enough.

vertical grimmace

My Feedback: (1)

Back to the "Expert" topic.

How many here actually know one of these ONLINE experts in person? That can be seriously frustrating as the cyber world is not generally the same as the real world. I will admit that I have engaged one of these persons in some pretty heated discussions in these forums. This is because the info being given was inaccurate, and would have been a serious dis service to the pilot asking the question. I had first person experience of their abilities. Funny how many revered this individuals experience in the forums, when in all reality they were a laughing stock at the flying field as by and large, they met with consistent failure.

speedracerntrixie

My Feedback: (29)

Could not not agree more! I once was invited to fly with an individual who was a regular here on RCU. He presented himself here as quite the engine expert and an above average pilot. I was shocked to realize that neither his engine nor his airplane were functioning anywhere near their potential. After that I took a break from RCU for a couple years ( unrelated reasons ). To my surprise when I came back a couple years ago, this same guy was regarded as one of the top engine experts here. He sure did write well though.

GallopingGhostler

There is a sense of power I imagine by such an individual. In the regular world, he is a nobody. All of a sudden, he is someone, an authority on the Internet, knows all the proper buzz words, eloquence in speech, etc. It's why I take just about everything said on Internet with a grain of salt. In the military they used to call such individuals barracks lawyers. It is one of the reasons why I don't post as much on the Internet. There's just no sense in having one's experiences denigrated, writing rebuttals, etc. It is a truly a waste of time, IYKWIM.

sensei

I personally know a few of them right here on RCU that give "Expert" opinions on subjects they know very little or nothing about like building, covering, finishing, piloting, and so on. At times they even give rebuttal on these subjects and yet when I have witnessed their completed projects, presentations, or their piloting skills in person... Well that has been another story because even though they talk the talk, and do it well, they certainly have not walked the walk well. So like others have already stated, the best thing is to find a club and spend a little time watching, and watching without talking, this may take a few visits, but if you pay attention you will indeed see for yourself who is doing the flying and who takes their airplanes for a ride to the field spending the day talking tales of greatness from the constraints of their lawn chairs, who is organized and courteous throughout the day with their presence and flying skills and who is not, you will see individuals that can honestly build well and setup a clean installation of equipment and so on, and who the mullets are that need to be avoidance. Once you have done this you will then know from whom to seek help from.


The truth is there is some very good information to be gleamed from other model enthusiasts on line but I suppose it can be just too confusing sifting through all the BS and controversy that comes from the simplest of questions.


Bob

speedracerntrixie

My Feedback: (29)

When all else fails, find someone at the local club being successful at what you want to accomplish and do what he does. LOL. Fictitious story, " Joe " has a YS 1.40 and is having issues. " John " has a YS 1.40 and it runs flawless. Joe is complaining to Pete about what a POS his YS 1.40 is and is wondering what John did to his to make it run so well. Pete observes that John is running XX fuel and XX glow plug and asked Joe why he is not using the same. Joe replies that he does not want to go out and spend the money and wants to make the engine work with what he has. Pete replies " you sell your frustration awfully cheap ".

BarracudaHockey

My Feedback: (11)

LOL no kidding.

I'm not an expert but I stayed at a Holiday Inn Express!

jester_s1

Yep, I was right back on page 3. 5 pages of this topic with people saying the same things over and over and over again along with some totally unrelated conversation on the side.

Yes, experts exist. An expert is simply someone who has achieved excellence and has a thorough knowledge of a subject. This common line that no one is an expert because nobody knows it all is faulty logic. I know who the experts are at my field. I have about half a dozen guys that I'll ask questions of, and generally I know who knows what because I know their experience. I don't expect them to know absolutely everything, but they do a lot and (even more impressively) they know what they don't know. Guys like that bring a lot of value to the groups they are a part of and deserve our respect.

GallopingGhostler

Expertise varies. Everyone is per say an expert at something they have mastered, although it may not be in the realm of model aeroplanes or a segment thereof.

A good number of experienced modelers I've met, will admit they don't know everything, but will help with that they know. There is a certain humbleness about someone who knows his subject really well, and does not need to justify himself. Those are the type of people I really enjoy associating with, because they have a wealth of knowledge to glean from.

Propworn

My Feedback: (3)

Ah yes I couldn’t agree more. People who hold true expertise in a certain field don’t have to go about attempting to quantify this by trotting out their certificates, accomplishments, job related experiences etc. They quietly go about their business helping out those who ask without having a need to bask in the limelight. One does not necessarily need a piece of paper to say they have expertise either. Simply years of experience and success in a certain endeavor certainly gives one a level of expertise. Again you will find most if not all have no need to parade their accomplishments for recognition.

Dennis

speedracerntrixie

My Feedback: (29)

I would say out in the real world this would hold true. However this is the internet so you can't see the " experts " or in this case guys with the experience and success in action the way you could at the local club. This is what gets my goat. There are times when I will hand out some perfectly good advise then someone comes along and tells me I am wrong. Then I feel that I have to quantify my advise by stating accomplishments. That's when the insecure keyboard pilots jump on the attack. That's why I will usually give my answer and if someone comes along and expresses a different opinion then we have a conversation and walk away both the better for it. If that same person just wants to prove me wrong then I leave the thread.

Propworn

My Feedback: (3)

Many years ago one of the best engine tuners I have ever met was already in his 60’s. He never refused to help if asked but he never interfered with the learning curve either. One of three things would happen. First was the person who just wanted the engine to run right and after a few minutes of trying half heartedly he might approach the fellow for help. He was only looking for someone to set it up for him and he was not really interested in learning himself. It took usually but a minute or two of the old guys time and the fellow went away happy. The second is the fellow who tried and tried before asking for help and made sure to ask to be shown how to do it. The old fellow saw this as an investment because the knowledge passed on would invariably be passed on again down the road by the new recipient of his knowledge. The third scenario is the fellow who felt the old guy had nothing of value to offer and as far as I know this particular person still spends more time trying to get his engine to run than flying. This gentleman not only had expertise in how to tune an engine but how to deal with different personalities and teach those with an inclination to learn and an interest in the subject. This by far at least to me is indicative of what I would consider an expert not the amount of certificates or letters after ones name.

Dennis

speedracerntrixie

My Feedback: (29)

Dennis, I would agree with that last post 100%. However that is obviously in a club setting. I think the original question has really gone un answered. On RCU if someone does not tell you how long he has been flying, what his successes have been or his accomplishments have been then how does one know if they are getting sound advise or just someone who is parroting something he read or heard? Personally when I have an issue I would like to find the guy with first hand experience.

Propworn

My Feedback: (3)

In reality there is no way other than your say so to verify your accomplishments that is why most likely they are so easy for those who choose to pick them apart. Accomplishments posted on the internet mean so little where good advise will certainly stand the test of time regardless of its detractors. This being said there are so many ways to skin the cat so to speak the other fellows ideas and experiences even in contradiction with yours may be just as valid. What it boils down to there may have been suggested 10 different ways to accomplish what you wish to do. All may work with varying degrees of success or ease of accomplishment. From these I am certain one will work for you. It’s not the end of the world to be called wrong or if someone decides not to follow your advice. I think credibility goes out the door when the argument degenerates into who’s right or who’s wrong.

Take for instance glo plugs. Personally I use only three types. If asked I will tell you and explain why. If I do this there will be plenty of others who will disagree with me and they will list their favorites. It doesn’t make me wrong. My advice is no less valid. It is simply what I have found works for me and I am passing it on for anyone who might wish to try them. Is it worth the time or effort to get into a discussion on my choices or what I may think qualifications that justify why I would offer that advice? No it would add no value to the discussion it’s simply a statement of what I prefer and what works for me. Am I open to the merit of others ideas or experiences. Of course in the case of glo plugs I have gone out of my way to acquire plugs I have not tried that were recommended by others and made my own determination to use them or not. If they didn’t work for me I did not have any desire to return to the thread and discuss it. I just choose not to use them. Others may have great success and be quite please using them who am I to say they are in error.

Dennis

vertical grimmace

My Feedback: (1)

To get good answers, really depends on the subject. Engine tuning, and reliable running is a tricky thing to solve on RCU. I always equated tuning an engine to tuning a guitar. There is a "feel" for it that has to be developed. This come from experience. And generally engine problems are more about setup than anything else. The last new guy at the field I helped that was having engine problems had a loose glow plug, and a hole in his fuel line from using needle nose to take the line on and off. Plus he was leaking around the needle, and then of course it was not tuned properly. You have to see these things to truly solve them. These issues may not get mentioned in here.

Now if I am wondering what a good engine choice is for a particular plane, or maybe I have questions on servo choice, those types of questions get solved quite cleanly in here.

jester_s1

I don't even think it's poor form to let people know about your accomplishments so they'll listen to you. There's a couple of guys at my club who I wouldn't have thought much of just from interacting with him. The first is a little awkward and goes off on unrelated tangents for a solid hour if you let him. Most avoid him. But I was having an issue with my gasser carb and he casually mentioned a background in racing and lots of experience with those carbs and offered his help. Turns out he used to be not just a racer, but a racing instructor! He's competed with everything from small 2 stroke go carts to sports cars. He even taught a few things to a current Sprint Cup NASCAR driver back when he was a youngster. Needless to say, the guy was able to fix me carburetor and teach me some things about setup and maintenance of these little 2 stroke gasser carbs. Another is also a bit awkward and can't let any conversation go without telling a story about himself. On the surface, you'd think he's just a goofy old man with his Ugly Stick who likes to get away from his wife on the weekends. Yet he competed at the AMA Nats for a long time, placing in the top 10 multiple times. So if I have a flight trimming question or need to work the kinks out of a maneuver, he's the guy I'm going to.
Yes, some perceive listing of your accomplishments as bragging and being full of yourself. Those who feel that way often don't have any accomplishments of their own. But I see nothing wrong with it. If you want people to listen to you, it helps for you to establish your knowledge with them first so they'll actually give you a chance.