Joggle Stress

[DesertBearhawk]

Guys, I feel I have made a series of mistakes, 170 of them to be exact....

I am in the process of painting my ribs with primer and it has occurred to me that I should from the Joggle before I paint the ribs. I think that I should have set the Joggles when I was forming the ribs (mistake #1)...

So I reviewed the thread on this topic from earlier this summer and I have tried both methods outlined. The "Joggle fork" method yielded poor results and I found this method to be difficult at best to deploy. I then tried method 2, using a block of steel with a relief cut in it for the Joggle and tried forming the joggle into this relief, I had better results than method 1 but I am still not satisfied that this is the way to go. I am having a hard time beating on my ribs and I am not getting the results I want for the effort I am putting in, not to mention risking cracking the ribs.

Needless to say, I am stressed out over this seemingly simple issue.

I took a test rib to the airport and talked with a friend of mine who does sheet metal and he suggested that I don’t Joggle them at all and just have the flange of the spar go over the flange of the rib and press on. He suggested that if I don’t like the "bump" that the lack of Joggle would cause (and he believes that it would be negligible) I could always make a .032 shim to cap the rib with. Any thoughts on this?

I don’t like the feeling of being backed into a corner; hopefully you guys have some good suggestions and words of encouragement.

[Enewton57]

I didn't joggle the center ribs on my Bearhawk and I would challenge anyone to look at it and tell a difference. Rivet placement is the key. Do not place a rivet near the edge of the spar flange. The skin will bridge the gap and unless you put a rivet right there you will never notice it.

[DesertBearhawk]

Thanks Eric! I sent you a PM.... Also it seems to me that I read somewhere that the factory does not Joggle the ribs either, can anyone confirm that?

[DRLPatrol]

Speaking of joggle questions. If you joggle as per the drawings the center rib goes in between the spar flanges, correct? If so what do you do at the full length tip rib, joggle the end of the spar flange to go inside the rib flange?

Doug

[Enewton57]

I faced to rib flange out on mine. Eric Newton - Long Beach, MS http://mybearhawk.com

[DesertBearhawk]

Eric, how did you deal with the back ribs and pocket ribs, same way?

[Enewton57]

Actually I joggled those. Why, you might ask? Well, someone posted a technique for joggling the ribs soI wanted to try it out.

[DRLPatrol]

I faced to rib flange out on mine. Eric Newton - Long Beach, MS http://mybearhawk.com

Yea, your are right. My bad. That is the way they are shown in the drawings.

Doug

[DesertBearhawk]

Eric, what method was that?

[N3UW]

Eric, What method did you use to Joggle the back ribs and pocket ribs. Could you post something about it. also Desert Bearhawk. I saw on your Facebook page that you fabricated up a joggling block. Have you tested it yet?

[mswain]

Thanks Eric! I sent you a PM.... Also it seems to me that I read somewhere that the factory does not Joggle the ribs either, can anyone confirm that?

Dave,

I bought the rib and spar kit, the factory ribs are joggled.

[Enewton57]

My method was not a good as some others I have seen so I don 't recommend it. I took a heavy bucking bar that was about 1/2" thick x 3" wide by 4" long. On the 1/2" think side, i used by bench grinder and ground a notch that was about 1/32" deep and 1 1/2" long, tapering the edges so there were no sharp edges. The rib was clamped to the bucking bar with the end of the flange where I wanted the joggle aligned with the notch in the bucking bar. I then used my plastic dead blow mallet to pound the rib flange into the notch.

[Gavin Chester]

I find the easiest way to joggle is to put it in the rib forming die.
1/16" offset ( under cut ) of the form die x 1/8" - 1/4" longer over all, than the flange of the spar, ( I used a 3/4" diameter cutter ), gave me very close to the .032" needed and a smooth transition.

[N3UW]

Are your forming blocks aluminum?

[Gavin Chester]

No . The 3/8" aluminum you see are the Master Templates I make for each rib piece , off the Master wing rib template. I use aluminum so I can scribe, center punch, drill, stamp, all relevant information on the Master to confirm and visualize how all parts fit together. The actual forming die is underneath and is made from UHMW plastic.

[DesertBearhawk]

I made a Joggle bar, kinda like what Eric described above and tested it tonight and it worked perfectly. I think I am out of the woods on this part of the project. Thanks to all who helped and suggested soultions.

[N3UW]

Nice. I will have to try that also.
Thanks