Comet
Sailplane Project
Well on Tuesday I closed Report No. 112
with the
rather cavalier comment: "I will get the wing
structure permanently joined tomorrow for sure".
It is now Thursday evening and I finally got the wing structure
permanently joined this afternoon. Nothing ever goes as fast or the
way you have it envisioned. I spent Wednesday and most of today
finishing up all of the detailed work on the two wing halves before
they were joined. For example, the ribs did not quite come up to the
top of the slots cut in the trailing edge as shown below.
So I went in and glued 1/16" square balsa
fairing strips extending from the slots forward up onto the ribs
themselves as shown below.
These were sanded down flush with the
trailing edge as shown below.
This is a side view close up showing the
faired in strips.
Then there was the matter of the dihedral
joint. The two sub ribs had to installed on either side of the
1/8" dihedral rib. The dihedral rib was glued in place and all of the
gussets and diagonals were added to finish out the joint as shown
below.
Finally around 4:30 p.m. this afternoon I
pinned down, jigged up, and glued the leading and trailing edges of
the right half of the wing to the left half of the center section.
Aliphatic glue was forced into the end grains of the leading and
trailing edge pieces to insure a good structural bond. Then glue was
added to the ends and the right half of the wing was pinned in place
as shown below from the front of the wing. The four spars were clamped
just to hold every thing in place, but not yet glued.
This is another view of the jig set up from
the rear of the wing.
This shows a leading edge alignment check
with the plan using a carpenter's square. Notice that the vertical
projection of the leading edge aligns with the plan down the edge of
the square.
Tomorrow, glue will worked down in between
the second spar overlap and clamp to let dry. Then the dihedral joint
will be strong enough to take up and the other three spars will be
glued and clamped.................Tandy