The
nose rib piece is notably flexible due to the "flat" connection between
the formed piece and L-Channels. The required forces to wrap
the nose skin will bend the nose rib piece over towards one side.
To resolve this situation, I
designed and built a simple support fixture out of scrap hardware store
angle and a miss-drilled spar cap (drilled in a mirror image of what
was required).Cost .... $0.00
The spar cap served as a
crossbar threaded through the lightening holes in the nose rib
pieces. The spar cap had #40 holes drilled at a 1-inch hole
spacing. That spacing was perfect for attaching the vertical
fixture pieces to the crossbar. Since the ribs are spaced at
16-inch spacing (with the exception of the two end ribs).
The
total parts were 7 vertical angles (15.25 inches in length with three
holes drilled) and one crossbar (8' feet long, holes spaced to match
rib spacing). Also, two #40 holes were drilled in each nose rib
piece (near the tip and near the flange). You could also drill a
hole in the bottom for attachment to the rib section laying on the spar
web.
A few Cleco
sheet holders and the whole setup becomes very rigid... and SQUARE. Yet, there
still is enough flexibility at the edge of the rib to postion the rib
as needed to align with the holes in the skin.
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Rib piece is easily bent to either side by down forces when installing the nose skin. |
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Crossbar and vertical support angle.
Look behind the angle to see the two extra #40 holes drilled
in the rib nose piece.
The two vertical holes are cleco'ed to the rib.
The third hole is cleco'ed to the crossbar. |
View of finished nose rib support fixture.
Only a few tools and a couple of hours required. | 
Testing for nose rib evenness by sliding 8' angle up-and-down the seven ribs.
Note: six ribs were "perfect" the end rib was off slightly due to a slight twist in the spar. |
Better view of the interconnections.
Three Clecos per rib required. |
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