Building a wing, need some advice.
09-30-2008 | 04:29 PM
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From: Harvey,
LA
Building a wing, need some advice.
Hello all,
I started to build the win for my Sig Four Star 40, and I am at the point where I am putting in the Shear Webs between the ribs. I got all of them sanded down to the proper fit, however, the instructions say that they should be centered on the lower spar and the notch for the upper spar(on the rib). If I get them to be centered on both, the shear does not sit vertical. So the question is, do they have to sit vertical or are they suppose to be slightly at an angle with the ribs? The booklet does not say anything being vertical.
Thanks.
I started to build the win for my Sig Four Star 40, and I am at the point where I am putting in the Shear Webs between the ribs. I got all of them sanded down to the proper fit, however, the instructions say that they should be centered on the lower spar and the notch for the upper spar(on the rib). If I get them to be centered on both, the shear does not sit vertical. So the question is, do they have to sit vertical or are they suppose to be slightly at an angle with the ribs? The booklet does not say anything being vertical.
Thanks.
09-30-2008 | 08:10 PM
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From: Monroe,
NC
RE: Building a wing, need some advice.
yes, as long as you get a verticle grain between and covering a good portion of both spars that is where the strenght comes from. i've put them on all kits I have built even if the plan doesn't call for it. Doesn't add much weight but makes a strong wing.
09-30-2008 | 09:28 PM
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RE: Building a wing, need some advice.
When the wing front to rear center line is horizontal as the airplane is flying, the top and bottom main spars are vertically over each other. Therefore the webbing when centered on the bottom and top spars is vertical.
On the plans take note of the cross sections of the wing at W1 & W2 and notice that the webbing is centered on each of the 3/16 X 3/8" spruce spars
also note on the plans about the middle of the right wing there is a shadowed cut away that shows the shear webbing centered on the spar
Picture #4 in the wing construction section of the booklet depicts the proper installation procedure. Notice to the right of the picture that the installed web is setting on the center of the lower spar and is centered with the notch for the top spar.
On the plans take note of the cross sections of the wing at W1 & W2 and notice that the webbing is centered on each of the 3/16 X 3/8" spruce spars
also note on the plans about the middle of the right wing there is a shadowed cut away that shows the shear webbing centered on the spar
Picture #4 in the wing construction section of the booklet depicts the proper installation procedure. Notice to the right of the picture that the installed web is setting on the center of the lower spar and is centered with the notch for the top spar.
09-30-2008 | 10:03 PM
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RE: Building a wing, need some advice.
perpendicular to the spar, grain going vertical from the wing panel being level, the issue your talking about is do the shear webs go vertical in conjunction with the diheadral, not really, just build the wing 1/2 on the board and put the grain vertically to the sparbeing horizontal. you'll be fine, does it really matter, no but it's standard building practice to make them exactly parallel to the ribs.
10-01-2008 | 02:20 PM
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From: Harvey,
LA
RE: Building a wing, need some advice.
ORIGINAL: w8ye
When the wing front to rear center line is horizontal as the airplane is flying, the top and bottom main spars are vertically over each other. Therefore the webbing when centered on the bottom and top spars is vertical.
On the plans take note of the cross sections of the wing at W1 & W2 and notice that the webbing is centered on each of the 3/16 X 3/8" spruce spars
also note on the plans about the middle of the right wing there is a shadowed cut away that shows the shear webbing centered on the spar
Picture #4 in the wing construction section of the booklet depicts the proper installation procedure. Notice to the right of the picture that the installed web is setting on the center of the lower spar and is centered with the notch for the top spar.
When the wing front to rear center line is horizontal as the airplane is flying, the top and bottom main spars are vertically over each other. Therefore the webbing when centered on the bottom and top spars is vertical.
On the plans take note of the cross sections of the wing at W1 & W2 and notice that the webbing is centered on each of the 3/16 X 3/8" spruce spars
also note on the plans about the middle of the right wing there is a shadowed cut away that shows the shear webbing centered on the spar
Picture #4 in the wing construction section of the booklet depicts the proper installation procedure. Notice to the right of the picture that the installed web is setting on the center of the lower spar and is centered with the notch for the top spar.
So what I am getting from what you are saying is put them at the angle of the wing and spars. Once the plane will be in the air, they will be vertical?
10-01-2008 | 02:26 PM
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From: Harvey,
LA
RE: Building a wing, need some advice.
ORIGINAL: planebuilder66
perpendicular to the spar, grain going vertical from the wing panel being level, the issue your talking about is do the shear webs go vertical in conjunction with the diheadral, not really, just build the wing 1/2 on the board and put the grain vertically to the sparbeing horizontal. you'll be fine, does it really matter, no but it's standard building practice to make them exactly parallel to the ribs.
perpendicular to the spar, grain going vertical from the wing panel being level, the issue your talking about is do the shear webs go vertical in conjunction with the diheadral, not really, just build the wing 1/2 on the board and put the grain vertically to the sparbeing horizontal. you'll be fine, does it really matter, no but it's standard building practice to make them exactly parallel to the ribs.
10-01-2008 | 04:08 PM
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From: Humble, TX
RE: Building a wing, need some advice.
It's very important to have the grain run vertical. Shear webbing isn't rocket science 
Just make sure that it makes good contact with both the bottom and top spar. I usually cut it flush with the spars after it dries. They do not have to touch the ribs so there can be a small gap there.
Just make sure that it makes good contact with both the bottom and top spar. I usually cut it flush with the spars after it dries. They do not have to touch the ribs so there can be a small gap there.
10-01-2008 | 07:42 PM
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From: Harvey,
LA
RE: Building a wing, need some advice.
I got them all glued in and everything is the way its suppose to be. I also got the sheeting done on one side, I'll have to continue tomorrow.
10-01-2008 | 11:04 PM
#13
RE: Building a wing, need some advice.
I am not sure if I am following every ones description correctly. But it sounded like the builder was gluing the bottom of the shear web onto the top of the bottom spar, is that why he said it was not vertical ? If I remember correctly the shear web should be on the backs of both top and bottom spars? Its been a long LONG time since I built this kit. Thats usually how its done. it was a litte hard to follow exactly what he was doing...
