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Author Topic: All inline models.  (Read 4507 times)

Offline Chris Wilson

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All inline models.
« on: July 14, 2015, 02:35:18 AM »
Hi, can anyone please tell me if an 'all inline' model (as in the model has one common datum line for thrust, wing and tail angle of attack) needs to use any more down thrust (or indeed any other angling device)  than a conventional (staggered) mid thrust line, low wing, high tail model?

My current belief is that an inline model 'should' need more datum deviance than a staggered one.

Thanks.
MAAA AUS 73427

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Offline MikeyPratt

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Re: All inline models.
« Reply #1 on: July 21, 2015, 09:52:40 PM »
Hi Chris,
The short answer is no.  They seem to work fine as is.  I've build a number of in-line models and they work great and very easy to trim.  I also tried adding down thrust and right thrust and it did help in some trim solutions, but not all.

Try one you will like it.

Mikey

Hi again Chris,
One of the best flying models I ever saw was Billy's in line Geo XL models that he flew at the team trials.  Great flyer but the side mounted OPS .40 kept breaking the the header.  When it ran the right way, it was awesome and was a joy to watch (both Billy and the in-line Geo XL).

I returned to the conventional setup with the big G Force and found it flew very well but took a considerable trimming to get it there.  Up & down thrust added along with adjusting the control ratio to get it to that locked in feel.
Another thing to consider is the a number of great models have center-line thrust.  The Shark, Skywriter just to mention a few.  I hope this helps.
Later,
Mikey
« Last Edit: July 23, 2015, 05:58:20 PM by MikeyPratt »

Offline Avaiojet

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Re: All inline models.
« Reply #2 on: July 22, 2015, 05:15:19 AM »
Chris,

There is this other Thread where you might pick up some related information.

http://stunthanger.com/smf/index.php/topic,36645.0.html
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Offline Chris Wilson

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Re: All inline models.
« Reply #3 on: July 22, 2015, 05:27:57 PM »
Chris,

There is this other Thread where you might pick up some related information.

http://stunthanger.com/smf/index.php/topic,36645.0.html

Um no Charles, the info in the linked thread about this topic was mostly my ravings - hence posting a more specific one just about inline 000 models.

I am just looking others opinions since that link doesn't give any, chiefly if more downthrust or incidence will be needed to trim the an inline 000 model than a conventional one.

Logically it would seem that the higher the thrust line the more turning moment you will have around the centre of drag but there already is a vote against that.

What do you see as related (asked for in this thread) information in that older thread?
MAAA AUS 73427

You have enemies? Good. That means you've stood up for something, sometime in your life.
 Nothing in life is so exhilarating as to be shot at without result.  It's not enough that we do our best; sometimes we have to do what's required

Offline Avaiojet

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Re: All inline models.
« Reply #4 on: July 22, 2015, 06:40:10 PM »
Chris,

Years back, late 80's and early 90's, there were a few R/C pattern ships designed with everything 000 on the thrust line. Proved not to be an advantage.

I thought Igor made a comment about that 000 on the thrust line. I took a look and I believe I'm mistaken. His comment was about P factor.

Sorry you went over there for naught. I would never send anyone on a wild goose chase.

I do hope you get your question answered.

BTW. Did you ever make use of the Super Tiger RE?

Trump Derangement Syndrome. TDS. 
Avaiojet Derangement Syndrome. ADS.
Amazing how ignorance can get in the way of the learning process.
If you're Trolled, you know you're doing something right.  Alpha Mike Foxtrot. "No one has ever made a difference by being like everyone else."  Marcus Cordeiro, The "Mark of Excellence," you will not be forgotten. "No amount of evidence will ever persuade an idiot."- Mark Twain. I look at the Forum as a place to contribute and make friends, some view it as a Realm where they could be King.   Proverb 11.9  "With his mouth the Godless destroys his neighbor..."  "Perhaps the greatest challenge in modeling is to build a competitive control line stunter that looks like a real airplane." David McCellan, 1980.

Offline Chris Wilson

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Re: All inline models.
« Reply #5 on: July 22, 2015, 06:49:26 PM »

BTW. Did you ever make use of the Super Tiger RE?


Good memory, not yet!
MAAA AUS 73427

You have enemies? Good. That means you've stood up for something, sometime in your life.
 Nothing in life is so exhilarating as to be shot at without result.  It's not enough that we do our best; sometimes we have to do what's required

Offline Avaiojet

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Re: All inline models.
« Reply #6 on: July 22, 2015, 08:17:09 PM »
Good memory, not yet!

I have a beautiful muffler for that engine. Really hard to come buy, never seen fuel.
Trump Derangement Syndrome. TDS. 
Avaiojet Derangement Syndrome. ADS.
Amazing how ignorance can get in the way of the learning process.
If you're Trolled, you know you're doing something right.  Alpha Mike Foxtrot. "No one has ever made a difference by being like everyone else."  Marcus Cordeiro, The "Mark of Excellence," you will not be forgotten. "No amount of evidence will ever persuade an idiot."- Mark Twain. I look at the Forum as a place to contribute and make friends, some view it as a Realm where they could be King.   Proverb 11.9  "With his mouth the Godless destroys his neighbor..."  "Perhaps the greatest challenge in modeling is to build a competitive control line stunter that looks like a real airplane." David McCellan, 1980.

Offline FLOYD CARTER

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Re: All inline models.
« Reply #7 on: July 24, 2015, 03:25:25 PM »
Just as many successful stunters have the wing slightly below the thrust line, and the stab slightly above the thrust line.  And I refer to several world-class pilots/designers.

Floyd
89 years, but still going (sort of)
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Offline Chris Wilson

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Re: All inline models.
« Reply #8 on: July 25, 2015, 01:47:30 AM »
Just as many successful stunters have the wing slightly below the thrust line, and the stab slightly above the thrust line.  And I refer to several world-class pilots/designers.

Floyd
Hi Floyd,
             just as many inline models have staggered datum lines?

I am not saying that one way is better than another just pondering the trim differences between the two.

I suppose that the ultimate here would be a counter rotating twin engine all inline model like the electric one posted here a while back.

Thanks.
MAAA AUS 73427

You have enemies? Good. That means you've stood up for something, sometime in your life.
 Nothing in life is so exhilarating as to be shot at without result.  It's not enough that we do our best; sometimes we have to do what's required


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