Rear Spars

[geraldmorrissey]

Getting ready to drive rivets on my rear spars. The wing to body attach hole is 1/4", should I take it out to full size now or leave it undersized until the wing is installed? How is the QB wing configured?
Thanks
Gerry
Patrol #30

[sjt]

I left mine undersize. The fuelage attach holes for the main and rear spar need to be colinear. The rear and main attach plate holes have to be match drilled for the wing to be able to pivot about fuelage.

I did some cad drawings:

https://bearhawkforums.com/forum/bea...spar-alignment image_7907.jpg

[geraldmorrissey]

Thanks for the response. Reassembled the scores of parts that make up the rear spar assy using my code on a tag for each part. I was concerned that I wouldn't get all the parts to go back together correctly but the coding worked! A couple of pictures.
Cheers
Gerry
Patrol #30

[Chewie]

Looks great Gerry! Did you have any trouble getting the pocket rib locations figured out? I remember going over that a few too many times.
I left my bolt holes on the spar fittings tiny - #40 maybe - but getting very close to throwing them in the jig and I expect to drill them out at least a little. I do not plan to make my spar holes collinear.

[sjt]

I believe the important thing is that the wing must be able to pivot at the fuselage. The length of the strut will set the dihedral, but that presupposes that it can pivot for the adjustment.

[sjt]

Chewie, can you post any pictures of your pocket rib installation. That is the last thing for me to do before I set wing vertical. I took special note of the video B-Spot did on youtube. He really did not like being upside down drilling and riveting them once the wing was vertical in a wing stand.

stan

[geraldmorrissey]

Talked to Bob today, he recommends 3/16" holes for the wing attach fjttings on the rear spars, 1/4" on the fwd spars. No spacer bars necessary to attach pocket ribs where there are capstrips. Just fasten the pocket rib attach angles directly to the capstrips. Concerning the pocket rib locations, I used the aileron hinge c/l's, the aileron assy dwg and the wing assy dwg to locate them. The only one that concerns me is the most inbd. Pretty sure I got it right. Bob was very patient with me and and answered all dumb questions. No show stoppers, good to start fastening, whew!!
Gerry
Patrol #30

[sjt]

The drill dimensions are about what I used. But they will some day be drilled out to mate at fuselage attach. I believe that when they are drilled out to a larger dimension they will be drilled at a slight angle.
That way the wing can pivot about fuselage attach.

image_7909.jpg

The above picture is from my solidworks drawings. The view is a 3 dimensional object that has thickness.
The picture shows the green rear fuselage attach steel. Even though the rear green fuselage fitting has thickness, you can not see the inside of the hole because the view is concentric with the green hole.
The green hole view is perpendicular.

If you look closely you can see that the purple wing attach aluminum is not quite round. Because of the thickness of the purple rear aluminum attach plate you can see something of the inside of the aluminum hole. For my part, when I drill the purple out to full size, I will try to enlarge the purple hole to full size. First I will use a rat tail file to start getting the hole to be in the right direction. If done correctly, I would not be able to see any of the inside of the purple hole. The purple and the green holes will be made concetric, the purple will still be undersize. Then I plan on using a drill and reamer once I have everything going in the right direction.

Gerry, thanks for the info on the pocket ribs.

stan

[Chewie]

Gerry that tricky inboard end of the aileron sounds familiar. I think I flipped that pocket rib around from my initial guess to make it position correctly.
Stan I don't think the wing needs to be a perfect hinge. Once the final dihedral is set you can weld the fittings to the fuselage at whatever slight angle (0.9° I think it was) they end up at.
I posted a link on my profile, go to the spars folder to see what I did with the pocket ribs, but it's just photos, no logbook or anything. And no promises that I did it right! :O