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Mis-Aligned J- Channel / right wing

Jskyking

Well Known Member
After getting the top wing skins in place and the left wing j-channel fitting perfectly, I moved to the right wing j-channel and discovered the short and the long J-channel is about 1/16 too high. I can see thru the dimple jchannel and out the top of the wing but it is too far out of alignment to fit a cleco.

I talked to Vans twice today, this morning they suggested to lightly bend the j-channel or as a last resort, take a dremel and remove a little of the material in the slot where the j- channel sits on the rib.

After experimenting with a piece of scrap , I tried bending the j channel and then tried adjusting the flange, neither worked. It appears that the j-channel is hitting the channel cutout at the point illustrated below. Comparing the right and left wing, the right wing jchannel dimples are slightly higher than the left.

This afternoon, I called back to Vans and they told me I could trim out the notch on the rib that is preventing the jchannel from going lower to capture the dimples in the wing ( had I drilled them accurately the first time, I wouldn?t be in this situation). The second option they said would be to reorder new j-channels.

My dilemma:
1. Do I take a dremel and remove a little ( approx 1/16?)of the rib cutout that is preventing the jchannel dropping into place ? Hopefully, having the J- channel dimple line 1/16 ? Higher than spec on the wing won?t affect the structural integrity nor will the rib integrity be affected by the shaping with a dremel. With the exception of two ribs, all are accessible with a dremel. The other two can be altered with a chainsaw file.

Or

2. Order new j channel, put it in place with cleco clamps, mark the holes thru the top skin, and use a drill press to final drill the # 40 holes then dimple.... quite a bit of work, and I would have to hope that the new holes holes and dimples match up. If the skins weren?t in place, I would order new j-channel.

Picture #1 depicts the offset. Blue dot is where the center of the j-channel hits the wing skin dimple.

Picture #2 depicts the area that would be removed to facilitate the nesting of the jchannel

Maybe someone has a better idea. Thanks
oqn.jpg


oCL.jpg
 
Trying to visualise

It's a bit hard to visualise the problem, can you post pictures with the j channel inserted?

I'm wondering if you can file a small 1/16 notch in the j channel skin flange at each of the rib positions to allow the rivet holes to align.
 
Contd Jchannel misalignment

Here?s a couple more pictures that will hopefully assist in reaching a good solution.
Thanks
Jt
oCY.jpg

oCl.jpg
 
Suggestions

The extra pictures help a lot. Apart from the interference problem I think the holes in the J channel look a bit too close to the edge for the channel web to fully do its job.
Before ordering more channel (the shipping will probably cost more than the part) I would try sliding the channel lengthwise slightly either way to check if there's adequate distance between holes for all new holes that are more toward the centre line of the channel flange.
As for drilling the new holes in the J channel, I would just match drill and cleco though the skin, using a helper to position the channel while drilling it.
 
Last edited:
Agree with Paul

The edge clearance on the J channel does looks minimal. My question is - if the holes in the J- channel were centered, would it fit between the wing walk doublers shown in the last image. It appears from the photo that the space between the doublers is not sufficient to allow the J- channel to sit flush against the top skin.
How does the completed left side look in comparison?
Hopefully it is just how it looks in the image. If you did get new J channel, would it fit between the doublers and allow the dimples to ?nest??
My wings are at the hanger so can?t verify how they look for a few days.
 
The extra pictures help a lot. Apart from the interference problem I think the holes in the J channel look a bit too close to the edge for the channel web to fully do its job.
Before ordering more channel (the shipping will probably cost more than the part) I would try sliding the channel lengthwise slightly either way to check if there's adequate distance between holes for all new holes that are more toward the centre line of the channel flange.
As for drilling the new holes in the J channel, I would just match drill and cleco though the skin, using a helper to position the channel while drilling it.

I agree with this. The J-stiffener was misaligned when it was drilled. Whether you replace it with a new one or find a way to reorient it, the misalignment is the underlying issue.
 
Thanks to all for weighing in....After looking at the issues and alternatives, ordered new j-channel.... if nothing else, a piece of mind, especially since the bottom skin jchannel on the right wing has the same issue.
Since the spar can no longer be used to match-drill, I ran a test piece today, clamping the jchannel in into place along the mid wing skin dimples and used the top skin holes as a pattern. Took the piece over to the drill press and placed 5 holes along the channel to be sure my work was repeatable. I deburred then dimpled the holes and clecoed it into place. Worked like a champ.....
As always, Thanks again for the sage advice from the folks on the forum.
Jt
 
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