ChiefK

Crank,

I'm surprised that the stab is not zero/zero to the wing. How did you arrive at the 3 degrees negative setting? Should I expect that my setup will be similar? I've been checking all our local HW stores for 3mm x 6 set screws. Haven't been able to find any. Do you have a source? Thanks for the info I haven't heard anywhere else.

Greg

crankpin

My Feedback: (15)

I remember using cap head metric. I can do some research later, also if you put up a new post on this forum, I am sure you can get many answer's. I am sure about the incidence. Usually flyer's of these Intruder's, would fly them first, then make the adjustment's before securing the stab. The last Intruder I have, the red and orange one, I have a 2150 mah 6V rx battery up in the canopy.

Vince

Taurus Flyer

I am sure about the incidence. Vince

Gents,

Of course we all read the posts, it is all interesting
When I read about the 3 degrees negative incidence of a stab (decalage, wing on zero?) of a pattern plane, question marks are growing in my head.
Is it a taildragger and do not know they the incidence of the wing?
Not knowing the Intruder but a lot about aerodynamics I did look and find a picture, an old picture.
Did draw the angles + and - 3 degrees of the stab in a combined picture. (Yes lines again!)

Differences of 6 degrees of a flying stab does let fly a plane in- and outside loops so differences of the stabilizer trim have to be within a half degree.
If not, there is something wrong with wing incidence and decalage and/or location of CG.

Maybe I am wrong (asymetrical airfoil of the wing for example) but before someone of you put a knife in the weakest point of the fuselage I would double check the value if I were you.

Cees

crankpin

My Feedback: (15)

Cees - Thanks, and I could be wrong. More later on this.

Vince

Taurus Flyer

Vince.

Youre welcome,
BTW flying stabs are commonly used on gliders, that's why I was triggered but still can be wrong.
Negative stab angles are commonly used on conventional tail draggers and sometimes on STOL airplanes.

Cees

ChiefK

Cees,

You have found a very old plan for the Intruder, but yes, it is basically the same design. The specifications for the plane I am assembling are: wing span - 1600 mm; wing area - 44 sq dm; flying weight - 3100 g; Fuselage length - 1500 mm. I do not have a three view drawing to post. It has tricycle gear, a symetrical airfoil for both the wing and the stabilizer ( the diamond airfoil for the stabilizer on your plan has been changed to standard curvature symetrical ). Fortunately, the stabilizer is a plug-in type (not a flying stab) and incidence is adjustable on the completed model and so the correct setting should be easily found. The wing has very little dihedral and is very close to a mid wing design location.

Greg

crankpin

My Feedback: (15)

Cees - This is not a flying stab. Included some picture's after stab has been set, on one of the Intruder's. Chief, I have posted a couple of picture's, showing pushrod method for elevator. I had to insert the front of the pushrod in thru the rear. As you can see, once all set it, then you can bring back thru the exit guide's. Of course this is all set up before the insertion. On the newer Intruder's, the tube's are there for the 3:48 wire. I believe a picture of the Intruder with the rear mounted servo's are on one of the post's here. Servo's are the JR3421SA digital mini's. Lot of pix here on stab for Intruder # 1, maybe # 2 also. I would also like to point out, I am not any type of aeronautical engineer. What I know about that, we could fill a thimble with.
Crank

Taurus Flyer

Greg, hallo,

The flying stab I only did write to show the effect of 3 degrees. So when adjusting the incidence it is comparable with a flying stab.
The diamant stab has special advantages most people do not know, they are forgotten.
A (few thents of degrees)) negative stab incidence adjustment we sometimes find also as result of downwash when using a flying stab on a glider.
For me a zero-zere incidence is, as we often see on pattren planes, a positive incidence as result of downwash!! This is why the position of the stab is important.
Look to the differences of stab positions of the both Intruders, old and new!!

Cees

Taurus Flyer

Crank,
I posted and you posted,
Read about the flying stab, I only did use the explanation to show what an adjustment of the incidence will do on the plane.
I knew of course the stab was not a flying stab, only -3 degrees of incidence is not normal!.

Cees

ChiefK

Crank,

Thanks for the additional pictures. I hadn't thought about taking the elevator pushrod in through the rear of the fuselage. Good idea. OK, I'm going to go see if I can find some 3mm cap screws for the stab trim adjustment. I'm thinking that the Sullivan slant style 12 oz tank should fit pretty well since it doesn't need the extra air space up front where the tubes come out, and physically, it doesn't look any longer than the smaller tank WM included.

Greg

PatternPilot

My Feedback: (58)

Greg,

try home depot or a Ace hardware for the hardware...

scott

ChiefK

Don't have a Home Depot or Ace HW anywhere near to local area. We do have a Lowes, but already checked there. Also tried a "Best" HW and a local non-chain HW. None of them have these really small parts. Also tried a really big "fastener" warehouse - same story.

Good news is that I found the already installed 3mm x 6 set screws in the stabilizer, and they were steel, NOT plastic, so that's OK. Bad news is that one of the 4mm "T" nuts in the firewall stripped out, so the shopping list is now different. We'll see how that search goes.

More good news ( I think )..... I got my 12oz ( 350cc ) "slant style" fuel tank installed. The whole thing fit into the area in front of the bulkhead that's in front of the wing. Just a little better comfort level with that one. With nothing currently flyable, I really need to get this Intruder finished and into the air. Today would have been a GREAT flying day here in NC ( if I'd only had an airplane to fly )! I guess it was great for some people......

Greg

PatternPilot

My Feedback: (58)

you could alway retap them in non metric . I have done this before.

scott

ChiefK

I'll consider that if I have trouble finding a 4mm T nut. It should be easier than
the 3mm set screw. Most of the metric stuff I've seen is stocked in sizes beginning with 4mm.

Greg

Taurus Flyer

Greg,

In Europe we do not have that problem of metric T nuts.
There was a period in the past they (T nuts) did not exist or we did not get them either. We did solder the normal nuts on a piece of sheet material and did glue that on the firewall.
Why not do that again, because this is Classic Pattern Flying, isn’t it?
Still interested what happened with my Three Degrees!
Picture is of the Oldest Taurus on Earth, replica, construction date original was about April 1961.

Cees

stuntflyr

The Intruder is back in stock.
here is a link;

http://www.xenonproject.com/rc-airpl...r-p-13501.html

Will be nice to get mine going, will take a trip to Fl to start it next month.

Chris...

Taurus Flyer

Stuntflyr, Chris,


Why not showing first the pictures you did promise? (LOL)


http://www.rcuniverse.com/forum/fb.asp?m=9530912

Cees

stuntflyr

Another puppy dies...

ChiefK

Cees, truthfully, I guess I'm a little spoiled by the availability of small items like "T" nuts. Maybe just a little bit too lazy to make my own, but also a "tool" issue. I don't have a decent solder system yet. That will be changing soon, as I have one on order. Hopefully it will help me improve my soldering skill. Anyway, I don't intend to waste a lot of time with this issue. If I have any trouble finding a replacement, I'll just switch it to a US equivalent and move on. Good point though, I'm glad you mentioned it. It'll remind me that there are many ways to accomplish something.

Crank will have to respond to the 3 degrees issue. I won't be able to respond until I get this airplane into the air.

Greg

Taurus Flyer

Greg,

The method with the nuts was only to show how far we can go (or stay home!) with classic pattern flying. So eliminate the need to leaf our workshop.
Sometimes we can use old methods. Of course I do also use modern nuts.
Most solder work I do with a 70 Watt iron.

INTRUDER
Because it does have my interest I did look for a while to the pictures.
As I told, a part of the decalage is result of downwash of the wings, down going airflow behind the wings.
The Kirkland Intruder did have the stab mounted high in the tail cone, see the picture. The wing was low positioned.
The Worlds Intruder the stab is mounted lower and the wing is mounted higher in the fuselage.
In my opinion the World Intruder stab does have more effect of down wash in horizontal flight, compare the ratio (L and H) of the squares.
Also in inverted flight the influence will be different.
In my opinion the result of this is, the stab of the World Intruder can have a few tenths of incidence negative, but absolute no more, (so negligible?).
Rest us the consideration the stab is the indicator for the flight path of the fuselage in normal and inverted flight and when we want low drag of it, the incidence has to be nearly 0 degrees.
In the early days pilots did change the incidence of the wing and not the stab and that has several reasons.
Even in the Simla "widwinger"of Ed Kazmirski it was (and for me, "it is"!) possible to adjust the the incidence of the wing.

Last point.
I normally look to drag, which part of the plane can generate drag?
Backside of the World Intruder canopy, change the angle as shown on the picture insert and MAYBE there is no more, or less turbulence of the canopy!! Positive result can be there is more profit of the canopy during “four points” and “slows”.

Cees

Balsawings

Cees,

I think Crank may be miss-typing/speeking/remembering the incidence for his stabs. If he set them the way I told him, they would be set to -.3 degrees of incidence. I always use +.3 for the wing and -.3 for the stab. Since the wing is set by the manufacturer, you have to set the stab to the wing. You then need to assure the engine incidence (down thrust) is -1.0 degrees to the wing. The right thrust is set by the manufacturer but should be about 2.0 degrees. I've built two Intruders to those specs and they fly/flew fantastic. One still flying, the other in airplane heaven.

I helped Crank quite a bit with his first two Intruders which has been two years ago now. I called for him at his first SPA contest as well. Crank builds some beautiful Intruders. He just can't seem to build one stock.

The Intruders and SPA lead me back into AMA pattern. I'm now flying Hydeouts.

Bob

crankpin

My Feedback: (15)

Bob is right. I had a memory lapse.[sm=spinnyeyes.gif] When I was ready to epoxy the stab's to the fuse's, Bob advised me from his experience with these Intruder's at his field. It was right on.

Thanks Bob, I was getting a veiled challenge from Cees, trying to figure out how to answer him, you did it for me. More later.

Crank

Taurus Flyer

Greg,

Do you see how I solve these problems. In a post of my own thread I did write on 19 August 2010:

Only work with facts, data and information you can double check. If you cannot double check an important part of information, don’t use it. It absolutely will disturb the end result.
http://www.rcuniverse.com/forum/fb.asp?m=9945876

Bob did “double check” the value for me, -0.3 degrees (so a few tenths negative)

Cees

Taurus Flyer

Bob and Vince,

Thanks for making this clear for Greg.

Bob, we are a little bit colleagues from each other, and Crank I see you have your teeth back!

I did fly Dutch Pattern (FAI) in the past and now Taurusses for fun.

Cees

PatternPilot

My Feedback: (58)

Bob,

Nice looking hydeout... you should check out the CPA (www.classicpatternassociation.com) and come on out and fly and have fun with us.. next contest in November in FL.

s.