Untwisted

Sunday 17th August 2008. 2hr 50min.

Attached platenuts to the left tank. Adjusted wing to eliminate 1/8 inch twist. Match-drilled top skins and leading edge skins to ribs and spars.

Just a short session this morning as, unusually, Dorothy is not travelling to look after her mother, so we decided to go out to visit Russborough house; a beautiful paladian mansion that most recently belonged to the Beit family and has a good art collection. Neither of us have seen it before. We both enjoyed it very much, though we are very spoiled for Georgian splendors in the Dublin area and we have more spectacular treasures at hand.

Installing the platenuts on the tank attach brackets was a simple repeat of the right wing and nothing new emerged.

However, I checked the left wing skeleton for twist using my two plumb-bobs and found that, unlike the 1/32 (negligible) twist on the right wing, I had a 1/8 twist on this one, which is outside the maximum 3/32 allowed. To fix it, I placed a short length of hardwood between the post and the bottom edge of the inboard rib so that it had to be angled slightly to go between them. I then clamped it to the post, which brought it back square and pushed this end of the wing away from the post. As both ends of the spar were clamped to the stand, this twisted the wing back towards square. With a little adjustment, I was able to completely eliminate the twist, with identical measurements from the plumb lines back to the aft spar at both ends.

I checked this set-up a number of times while match-driling as it does not seem as solid as the arrangements that other builders have used (essentially a lower bracket on both posts, made of 3X2) but it did not move.