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Correcting incidence

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Correcting incidence

Old 05-20-2013, 06:31 AM
  #101  
Zor
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Default RE: Correcting incidence

What determines the flying characteristics of a model is not the angle of incidence of the stabilizer.
It is the decalge angle between the main wing(s) and the stabilizer and the CG location.

Imagine for a moment that we have the main wing(s) incidenceat zero degree; in different words the chord of the main wing(s) is parallel to the selected reference line and the stabilizer incidence is also zero degree. The decalage angle is zero.

Now we change the reference line by two degrees or by any small angle. The measurement of the incidences will simply change by the same amount as the reference line was changed. In fact we have changed nothing structurally.

Another situation . . . Imagine that we use the original reference line and actually set both the main wing(s) and the stabilizer to minus two degrees; the decalage will still be zero but the longiudinal axis will have changed attitude by the two degrees. This may change slightly any lift contributed by the fuselage or any components having some lift effect. The same is true for any small angle.

The trajectory of any model is the trajectory of its CG. The ideal (the best) compromise is to have the thrust line parallel to the trajctory while simultaneously neutralize any pitch variation with speed. That is impossible thus the necessity to trim with elevators when the speed varies.
What in effect is happening is that we have to change the decalage and in effect we are changing the tail dynamic incidence.

Again, ideally, it is best to have the incidence of the stabilizer and the main wings (the decalage) for the airplane to be stable in pitch attitude at cruise speed with neutral trim (elevators in line with the stabilizers). It must be realized that none of this is important to a flier that never flys straight and level or in a steady descent or climb or let the model fly hands off.

Now have your fun guys and do not justify or back up your nasty statements since you cannot find good reasons to do so.
As long as you enjoy the hobby and depreciating me ___that is fine ___it reflects on you and what you represent in the world.

As I wrote a long time ago, I do not glue my stabilizers, I bolt them so I can experiment with decalage and optimize my models.
For who commented about my posting only pictures of my Skybolt and commented about the awful looking cowl and awfull finish of the whole model has not seen other threads nor would understand that I did not previously had a camera suitable to post pictures. It does not matter, his pleasure was in writing nasty comments.

Zor


Edited to add a letter in one word

P.S.: Posted by Zor by editing on 20 May 2013 at 20:50 EDST to explain that a fine gentleman moderator posted early this afternoon and asked that the nasty posting be edited. My comments above about nasty posting do not apply anymore as the people edited their postings.

Note that many nasty postings from the same individuals remain in other threads.
I (Zor) am dedicated to obey the forum rules and did not address myself to the ones who were nasty and posting derogatoy statements.

Thanks to the moderator"Deadeye" who intervened at 1:01 PM today.

Zor

Old 05-20-2013, 07:25 AM
  #102  
MTK
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Default RE: Correcting incidence

One piece stabs and wings that are screwed in, can be adjusted. Making them infinetesimally adjustable with a screw mechanism, now that's the cat's meow. Straight forward to actually do tho.

If you ever decided to build plug in stabs and wings,making them adjustable is elementary. The adjustment mechanisms are simple to build from phenolic tubing
Old 05-20-2013, 08:05 AM
  #103  
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Default RE: Correcting incidence

More weight in the tail and one more thing to forget to check in pre-flight. I like getting the construction right in the shop and go fly.
Old 05-20-2013, 09:01 AM
  #104  
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Default RE: Correcting incidence

It's been brought to my attention that thread has some personal attacks in it. I have read most of the thread as my time allows, and have found several unnecessary comments. I will leave it up to the posters to clean up their own mess. If, after a couple of days, things aren't fixed; then I will have no choice but clean things up myself. If I have to do that, it won't just simply stop at that. There will be action taken against those members that like to stir up the hornets nest.

To the trouble makers: You have been warned.
Old 05-20-2013, 10:20 AM
  #105  
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Default RE: Correcting incidence

ORIGINAL: vicman

I like getting the construction right in the shop and go fly.
I wholeheartedly agree with you. I thought that was the goal of this thread in the first place. If not in the shop, then through the advice of those with experience with your partucular model. That's what I did in my case. There were several modelers that have built the YMF and from their experience, they recommended more stab incidence than set through the construction of the kit. I'll go with experience anytime.

Old 05-20-2013, 10:46 AM
  #106  
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Default RE: Correcting incidence


ORIGINAL: vicman

More weight in the tail and one more thing to forget to check in pre-flight. I like getting the construction right in the shop and go fly.
My construction isn't just right....it is pretty darned close to perfect. My precision is within a few thousandths of an inch. But so what??

When one flies the types of models I do, (top level aerobatics competition), one tries to extract the absolute maximum performance out of a model......it minimizes the workloadon me, thepilot, in the middle of comp flight.The final decalage and any other angles for that matter are finalized over time as the model is trimmed for perfect flying. Iabhor using electronic fixes for anything we do in the flying. It is the last resort, not the first

That's where having built in adjustable wings, stabs, engine mount, and dihedral come in very handy. I know this is advanced stuff and the average sport flier would never even attempt them or has even thought about them. But that's how the game is played whereI play.....

But that's waaaayyyy over the top for what Bill was asking in his original post, No? For Bill, getting things back to some semblence of correctness is most important
Old 05-20-2013, 10:52 AM
  #107  
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Default RE: Correcting incidence

You are on target Matt.

I guess after building as many pylon racers as I have setting incidence becomes a bit routine. I've also built a few little fixtures to make it easier. There have been some long time racers that steered me in the right direction from when I started.
Old 05-20-2013, 04:47 PM
  #108  
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Default RE: Correcting incidence

But that's waaaayyyy over the top for what Bill was asking in his original post, No? For Bill, getting things back to some semblence of correctness is most important
Matt,
Your astute assessment of the task and my ability is amazing. Almost no one understands the degree of difficulty for a non builder. It took ten days to get a semblance of correctness but I am happy with the results. In the beginning the task was considered impossible. The next similar project will take half the time

Now I am attempting to decide if I can fit a new cowl. But one should not overstay their welcome.

THANKS EVERYONE except for one agitator.

It is not a given that others have knowledge to share. I have decided to skip over and ignore anything from Mr. Hates Everyone. It is entirely possible that he is 15, has no airplane experience, has no airplanes,, and is simply a blow hard and trouble maker.

The following URL gives a general idea of what my company does. The work presented by my customers is very neat.
http://www.engsw.com/drawroom/


Bill
Old 05-20-2013, 04:58 PM
  #109  
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Default RE: Correcting incidence

Balsa or FG, Bill?
Old 05-20-2013, 06:47 PM
  #110  
BillS
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Default RE: Correcting incidence

Vic,

A new standard Kougar plastic cowl needs to be fitted. The last time I fitted a cowl it took 30 days.

Bill
Old 05-21-2013, 08:10 AM
  #111  
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Default RE: Correcting incidence


ORIGINAL: BillS

Matt,
Your astute assessment of the task and my ability is amazing. Almost no one understands the degree of difficulty for a non builder. It took ten days to get a semblance of correctness but I am happy with the results. In the beginning the task was considered impossible. The next similar project will take half the time

Now I am attempting to decide if I can fit a new cowl. But one should not overstay their welcome.

THANKS EVERYONE except for one agitator.

It is not a given that others have knowledge to share. I have decided to skip over and ignore anything from Mr. Hates Everyone. It is entirely possible that he is 15, has no airplane experience, has no airplanes,, and is simply a blow hard and trouble maker.

The following URL gives a general idea of what my company does. The work presented by my customers is very neat.
http://www.engsw.com/drawroom/


Bill
Bill, that's great. I hope it is flying reasonably well for you. Of course that's how we all learned; first time the task is always daunting. It's been nearly 50 years since my start in modeling and I'm still learning. Okay sometimesI relearn stuff I've forgotten. And now, with my 9 year old grandson at my side, I get to teach a very willing pupil. Nothing makes me prouder than whenI see his creations take flight and marvel at and bask in his excitement.....Just last night he finally flew his R/C Night Vapor under his complete control and by himself for nearly 1/2 hour. Didn't crash it once. The fact that he too felt the sheer fun of it, well,I'm still smiling, remembering my first independent time RC'ing.....

I read some of the posts from Zor and he says some technical things that are correct. How the thread managed to get so convoluted, I'm not sure but I am glad you got enough good info to make informed decisions.

On cowl fitting, don't fret it. You might try to cut and fit a cardboard/posterboard pattern first on the fuse top, before committing to the plastic. RC56 glue works well to secure. Use a strip of masking tape to hold it down while the glue dries

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