Bi-Plane with-out cabanas
02-12-2012, 06:15 AM
#1
Thread Starter
My Feedback: (18)
Join Date: Apr 2008
Location: Eure,
NC
Posts: 632
Likes: 0
Received 0 Likes
on
0 Posts
Bi-Plane with-out cabanas
I picked up a plane at a swap-meet the other day and have a question. It is a bipe and has no cabanas on the outer wing. The plane appears to be complete and I was wondering if any-one knows of one that was designed without them. I need to know where to balance it,and short of doing the calculations which I did best I know how, it would be nice to know what it is.
a person can get a better idea what it is.
02-12-2012, 06:41 AM
#3
RE: Bi-Plane with-out cabanas
Those struts are called interplane struts. it is ok for that kind of biplane. Cabane struts are the ones next to the cockpit. I was hopping to see a plane without those.
02-12-2012, 07:23 AM
#4
My Feedback: (6)
Join Date: Oct 2002
Location: Mountain Home,
AR
Posts: 2,684
Likes: 0
Received 0 Likes
on
0 Posts
RE: Bi-Plane with-out cabanas
I have a Sig Liberty Sport that I built from a kit a long time ago. The instructions say that the plane was tested and can be flown successfully without N struts (interplane struts). They look nice but are not absolutely necessary. There are no doubt others as well. Take a couple pictures from the side of your airplane and maybe somebody can identify it.
02-12-2012, 09:28 AM
#5
Thread Starter
My Feedback: (18)
Join Date: Apr 2008
Location: Eure,
NC
Posts: 632
Likes: 0
Received 0 Likes
on
0 Posts
RE: Bi-Plane with-out cabanas
I think it has been flown but not for sure. It has a .36 engine. Nice little plane and what I like the most is how easy it is to take down and put together.
02-12-2012, 09:49 AM
#7
RE: Bi-Plane with-out cabanas
If your plane is not this one, it is pretty close:
http://manuals.hobbico.com/gpm/sport...-40-manual.pdf
http://manuals.hobbico.com/gpm/sport...-40-manual.pdf
02-12-2012, 12:24 PM
#10
My Feedback: (90)
Join Date: Dec 2001
Location: Elephant Butte, N.M.
Posts: 6,715
Likes: 0
Received 2 Likes
on
2 Posts
RE: Bi-Plane with-out cabanas
It's a Tiger Bipe .40 ARF
http://www.rcpro.no/main.aspx?page=a...no=CA40.TT4557
manual: http://www.rctube.eu/download/rc/ins...er_bipe_40.pdf
http://www.rcpro.no/main.aspx?page=a...no=CA40.TT4557
manual: http://www.rctube.eu/download/rc/ins...er_bipe_40.pdf
02-12-2012, 12:25 PM
#11
RE: Bi-Plane with-out cabanas
If a Tiger, here is the manual then:
http://www.rctube.eu/download/rc/ins...er_bipe_40.pdf
Copied from a published article of Andy Lennon:
AERODYNAMIC CENTER (AC) LOCATION
For a biplane, locating this center is not difficult. First, the AC of each wing lies farther forward on a biplane at 23 percent of the chord rather than the 25 percent of a monoplane's.
For an orthogonal combination, the AC is on the vertical line joining the 23 percent of chord of upper and lower wings.
For staggered combination of equal area, span chord and aspect ratio, the situation is different. For negative stagger, the AC is located midway between the wings on the line joining the 23 percent of chord points. For positive stagger, it is at 57 percent of the distance from lower chord to upper chord measured on the line joining the 23 percent of chord points.
Where the wing's areas are unequal, the vertical location along the line joining the 23 percent of chord (MAC for tapered wings) is fixed by the following formula:
X/Gap = Upper wing area X P / Upper wing area X P + Lower wing area
where:
X=distance of the mean chord from the lower chord, and P=a weighting factor of 1 for negative stagger and 1.35 for positive stagger.
See attached schematic.
For the MAC of each wing, you can use the on-line calculator listed in the Aerodynamics forum.
This is another article explaining how to determine CG:
http://www.modelairplanenews.com/blo...cing-biplanes/
http://www.rctube.eu/download/rc/ins...er_bipe_40.pdf
Copied from a published article of Andy Lennon:
AERODYNAMIC CENTER (AC) LOCATION
For a biplane, locating this center is not difficult. First, the AC of each wing lies farther forward on a biplane at 23 percent of the chord rather than the 25 percent of a monoplane's.
For an orthogonal combination, the AC is on the vertical line joining the 23 percent of chord of upper and lower wings.
For staggered combination of equal area, span chord and aspect ratio, the situation is different. For negative stagger, the AC is located midway between the wings on the line joining the 23 percent of chord points. For positive stagger, it is at 57 percent of the distance from lower chord to upper chord measured on the line joining the 23 percent of chord points.
Where the wing's areas are unequal, the vertical location along the line joining the 23 percent of chord (MAC for tapered wings) is fixed by the following formula:
X/Gap = Upper wing area X P / Upper wing area X P + Lower wing area
where:
X=distance of the mean chord from the lower chord, and P=a weighting factor of 1 for negative stagger and 1.35 for positive stagger.
See attached schematic.
For the MAC of each wing, you can use the on-line calculator listed in the Aerodynamics forum.
This is another article explaining how to determine CG:
http://www.modelairplanenews.com/blo...cing-biplanes/
02-12-2012, 02:22 PM
#12
Thread Starter
My Feedback: (18)
Join Date: Apr 2008
Location: Eure,
NC
Posts: 632
Likes: 0
Received 0 Likes
on
0 Posts
RE: Bi-Plane with-out cabanas
Thanks for the help guys! Always nice to know what you got. Turns out the CG was dead on. Just need to test top her. I will do that Wednesday at our weekly meeting of "The Liars and Fliers" at my club. Will post the on-board video Wednesday afternoon.
02-12-2012, 03:46 PM
#14
Senior Member
Join Date: May 2007
Location: stony point, NY
Posts: 290
Likes: 0
Received 0 Likes
on
0 Posts
RE: Bi-Plane with-out cabanas
from the pics the cabanes are terribley out of line. i think you are refering to the N struts. they brase the wings and probably should be installed.
02-13-2012, 06:17 AM
#16
Senior Member
RE: Bi-Plane with-out cabanas
I've found that the inter plane struts come in handy if doing any violent aerobatics. Should the cabanes be slightly weak or the top wing firmly attached to them, you can find the upper and lower wing tips on one side or the other touching in such things as snap rolls etc. The inter plane struts prevent this from happening.
02-13-2012, 09:38 AM
#17
My Feedback: (21)
Join Date: Oct 2003
Location: Blairstown,
NJ
Posts: 491
Likes: 0
Received 0 Likes
on
0 Posts
RE: Bi-Plane with-out cabanas
I have a newly assembled Tiger Bipe 40 hanging in my basement (been there a while). I have a TT Pro .36 in it. Hope to fly it this Spring. Neet little bi plane, but I do not believe it will be a "barn burner" - just a little knock around Sunday flyer. Good luck with yours.'
Steve
Steve
