12
compared to the trailing edge length seen on the layout drawing. Glue on the root rib’s cap
strips so they only extend outboard (inboard flush with the rib).
5.b. Trailing Edge: The bottom cap strips provides a platform for the attachment of the trailing
edge wire. This assures uniform mounting and a straight trailing edge. Glue .015 inch (.4mm)
wire to each rib. Trim the bottom cap strips flush with the rear of the trailing edge.
5.c. Top rib caps: Add the top cap strips. You will have to bevel them slightly at the front to
mate with the leading edge. Trim even with the trailing edge. Sand the front top to be plane
with the leading edge with very fine sand paper. This should be minimal and be careful not to
sand the leading edge plywood as the top veneer is very thin.
5.d. Rear spar
:
The Rear Spar is made of .040 inch (1mm) square stock cut to length to fit
between each rib. It is best to reattach the wing structure to the drawing and cut some 1/64 inch
(.4mm) spacers from scrap to hold the spar pieces the correct distance off of the building board.
Glue the spar pieces in place as shown on Sheet C. Don’t glue on the trailing edge braces quite
yet.
5.e. Trailing edge braces: At the root and tip there is an angled brace (shown on Sheet C) that
holds the trailing edge taught. They are made of
.040 inch (1 mm) square stock. Cut and glue into
position from the rear spar to the trailing edge of the
root and tip ribs.
5.f. First finish: Finish the wing with a couple of thin
coats of clear semi-gloss or matte spray before
doing the next steps.
5.g. Lower leading edge bracing: On the original
Dr1, the lower lip of the leading edge is tied to the
spar with pieces of tape, woven material much like a
wide ribbon. On this model
1/16 inch ribbon is
used. Cut pieces of ribbon to 3/8” inch (10 mm)
long or slightly longer. Glue them on as shown in
Figure 1.10 between each pair of ribs.
5.h. Rib Twist Bracing: To keep the thin ribs from twisting, ribbon is woven between them as
shown in Figures 1.1 and 1.10. Rib twist bracing is made from the same ribbon as the Lower
Leading Edge Bracing. Best to cut a single length (about 18 inches (46cm long), glue one end
directly over the rib stiffener on the root rib (either on top or bottom) and then weave it through
to the tip. Pull it taught, making sure it is straight and then glue to each rib. Then, wrap the
ribbon around the tip and follow the same procedure back to the root. Coat both the leading
edge bracing and the rib twist bracing with clear finish or thin cyanoacrylate.
5.i. Connect the two wing halves together: Ensure that the ends of the spars are flush and
aligned. Make sure the root ribs are at least 1.77 in (44mm) apart at spar. Insert and glue the
Spar Connectors (WW9) to the front and rear of either wing. Then slide the other wing on and
glue in place.
5.j. Tip skid: The lower wing has an iconic tip skid. This is made from 3/32 square (2.4 mm)
stock 2” (50mm) long. Sand to shape. Paint dark brown.
Figure 1.10 Rib and Leading Edge
Bracing
