SKIN DEFORMATION - Design defect in stabilator rib noses
Posted: Tue Feb 22, 2022 8:05 am
Warning: Serious skin wrinkle potential!
There is a design defect in both stabilator rib noses, which causes interference and deformation in the outer skin leading edge. Right and Left stabilators had the same issue:
- Too long.
Had to trim and shape nose rib to allow smooth mating of rib to skin using Dremel tool
- Mis-shaped
Rib vertical aluminum juts into skin, causing a serious wrinkle
I trimmed and rounded the aluminum around rivet contact area.
This allowed the nose rib to flex and/or smoothly contact the skin, eliminating skin deformation.
- Mis-shaped Skin
The forming tool needs an update.
This issue could be resolved by increasing the diameter of the leading edge of the skin.
The photo shows the skin curve diameter could be increased.
This problem occurs only after the skin is pulled tight against both top and bottom of the frame.
Several trim iterations were required. Photo shows shape after 1st iteration. A 2nd and 3rd iteration was required on the outer nose rib because about 1/4 inch needed to be removed in some areas.
See: https://eaabuilderslog.org/showmy.php?p=7pS0BwoB0&z3=&i=12823659&l=153509&t=f&f=DEFORM.jpg
There is a design defect in both stabilator rib noses, which causes interference and deformation in the outer skin leading edge. Right and Left stabilators had the same issue:
- Too long.
Had to trim and shape nose rib to allow smooth mating of rib to skin using Dremel tool
- Mis-shaped
Rib vertical aluminum juts into skin, causing a serious wrinkle
I trimmed and rounded the aluminum around rivet contact area.
This allowed the nose rib to flex and/or smoothly contact the skin, eliminating skin deformation.
- Mis-shaped Skin
The forming tool needs an update.
This issue could be resolved by increasing the diameter of the leading edge of the skin.
The photo shows the skin curve diameter could be increased.
This problem occurs only after the skin is pulled tight against both top and bottom of the frame.
Several trim iterations were required. Photo shows shape after 1st iteration. A 2nd and 3rd iteration was required on the outer nose rib because about 1/4 inch needed to be removed in some areas.
See: https://eaabuilderslog.org/showmy.php?p=7pS0BwoB0&z3=&i=12823659&l=153509&t=f&f=DEFORM.jpg