Aileron Pocket Skin

[rodsmith]

Finally getting around to installing these pieces on the wing. I initially tried to force the flat pieces into a curve and clecoed them to the pocket ribs. The pieces were stiff enough that even with everything clecoed together tight against the pocket ribs,the skins were pushing the top wing skin up at the trailing edge, certainly didn't want to rivet it together that way. I have a 30" 3 in 1 sheet metal machine that I bought used primarily for the shear. Had to learn how to use the slip roll. I don't think the previous owner had ever used the roll as I couldn't turn the bolts that compress the top roller in enough to work (Chinese made). Pulled them out and used a tap to clean the holes up. Was able to match the curvature of the pocket ribs with no problem. 1 of the pieces for each wing is 40" so I had to find a machine shop with a longer slip roll. I took the longer pieces in with a short one I had rolled for them to match the curve. Took them 5 minutes and charged me $10. The flange at the upper skin had too much angle so I flattened the angle using the shoe on my sheet metal brake. When I put everything back together the top skin layed flat instead of being pushed up. The flange at the top skin stuck out about 1/4" from the wing skin so I trimmed it to match. This is an older wing kit so not sure these pieces are still the same. In the kit they were made from .025 instead of .020 shown on the plans.

[Bcone1381]

Did you make the skin from scratch? Did you have it primed before applying the roller to it?

My EAA chapter has an old slip roller and I used it to help form the curvature in my Boot Cowl Skins. I stopped fighting with the skins after I applied the right curvature. Its such a nice tool to have available.

[rodsmith]

These came with the quick build wings, already primed.

[nichzimmerman]

That sounds like an ideal way to do it. I bent mine by hand over a 3 inch pipe and got pretty good results. I found it was easier to over-bend a little at first, then drill in place. I was also using .020" though so my technique might be harder with .025".

[Dpearson]

I'm struggling with these cove covers/pocket skins. Background: This 4-Place kit is very old, manufactured in 2006, and I'm the third owner. So no warranty!
The cove cover parts "as delivered" by Avipro (almost 2 decades ago) have the two bends (one where the cover touches the top skin, and the other where it contacts the bottom) already formed but were otherwise flat.
I used the nichzimmerman technique to bend over a piece of 3" pipe to get the curve between the bends "dialed in" with good results. After some fine tuning I have a good fit at the bottom skin and around the curve, but where the cover meets the top skin the fit is lousy and the cover wants to push the trailing edge of the top skin up. I've convinced myself that the bends in the cove covers "as delivered" are just a bit too far apart - put another way, there is too much material between the bends.

I'm headed down the path of making a cardboard template and starting "from scratch" to remake these cove covers with shorter "bend to bend" spacing.

Here are photos of one cover clamped in place, and also held up against the tip rib (which makes a handy template). With the bottom bend all lined up, and the cover up against the fingers of the cove rib, the top bend of the cover ends up about 1/16 above the top face of the tip rib.

Any advice or suggestions (particularly pointing out any boneheaded mistakes on my part) would be welcome!

[fairchild1934]

could you move that rear bend line in a bit (maybe 1/4 inch) and then not bend the flange quite so much ?

PS--- I see a bolt head on the spar--- does that washer need to be under the nut and not under the head ? I don't know what that is holding -( bellcrank legs ?) just asking ---

[Dpearson]

Yeah, unless someone has a suggestion for how the parts from my ancient QB kit can be used, I will re-make them with the bend line moved in as you suggest. Your eyeball estimate is good - 1/4" is about the right amount according to my CAD (Cardboard Aided Design).
The bolt you mentioned is for one of the aux tank straps. There is a washer under the nut inside the tank bay too.