spacewalker SIGRC61, Building And Flying Instructions

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Fitting The Wing To The Fuselage
NOTE: The wing center section, completed through Step 38, is needed for the following steps.
85.
The wing saddle area must be carved at an angle for the wing to seat properly on the fuselage. Use the plywood side
pieces PS-1 and PS-2 to act as guides which should not be altered. Sand the balsa until you reach the edge of the plywood,
then stop. Use the Wing Saddle Carving Guide (Plate 2) to check your progress as you work. If you should overcarve, do
not fix it by trying to reshape the bottom (which could cause a change in the wing incidence). Instead, fill the gap with model
putty. Lay the wing center section in the wing saddle and check the fit.
86.
a. The remaining two W-1A sub-ribs are positioned in the wing center section so that they line up with the fuselage
sides. With the center section positioned accurately on the fuselage, lay a straightedge along the fill strip on the
fuselage side so that it extends over the wing. Now mark the bottom leading edge sheeting with a soft lead pencil.
b. Remove the center section from the fuselage and carefully cut away the bottom leading edge sheeting at the line.
Don't cut the spar!
c. Trial fit the W-1A sub-ribs and trim as necessary. Glue the subribs into the center section so that they rest against
the cut edge of the leading edge sheeting.
87.
Two pieces of 5/8"x3-1/4"x1" balsa are provided for landing gear support blocks. These are installed against the back of the
leading edge, with the grain running vertically. Notice that the top of the support blocks must be sanded to the contour of the
top leading edge sheeting. The bottom of the blocks should be flush with the cutouts on the W-1A sub-ribs. When satisfied
with the fit, firmly glue the blocks in place. Look ahead to photo 89-90 to see the blocks glued in place.
88.
a. Glue the 1/8" plywood PW wing hold-down straps to the inside of the fuselage. The top end of PW butts against the
bottom of the 1/4" sq. balsa crossbrace.
b. Brace the back side of PW to PS-1 with 3/4" triangle stock. When dry, carve the triangle stock to match the wing
saddle.
89.
a. Use the "Cross Section at F-2" (Plate 1) to locate and mark the position of the wing hold-down dowel on PW.
b. Drill PW at the mark with a 1/8" pilot drill, then follow up with a 5/16" drill.
90.
a. Sharpen one end of the 5/16" dia. x1-1/2" long wing hold-down dowels, being sure to keep the point centered. Push
the dowels into the PW pieces from the front so that just the points stick out the backside. (It may seem that the
dowels go into the holes awfully hard, but they'll loosen up after they've been pushed in and out a few times.)
b. Carefully slide the wing into position, pushing the sharp dowel points into the wing leading edge.
c. Remove the wing and drill two 5/16" dia. holes through the wing leading edge at the punch marks.
91.
a. Remove the dowels from the PW wing hold-down straps. Reinsert the dowels from the other side through pieces of
wax paper. Only push the dowels in 5/16" - leave most of the dowel length sticking out.
b. Trial fit the wing in position, sliding it onto the dowels. Check to see that the wing still fits the fuselage. If not, slowly
enlarge the holes in the wing leading edge until it fits properly. When satisfied with the fit, coat the inside of the holes
in the wing with epoxy and slide it back in place on the fuselage. When dry, carefully remove the wing and fill any
small gaps around the dowels at the wing leading edge with another application of glue.
92.
a. The 3/4"x3/4"x3" basswood wing mounting blocks must be beveled on the side
so that they fit flat against the fuselage side (PS-2) and the top surface of the
wing. Check their fit by installing the wing on the fuselage and holding the block
in place. When they fit properly, epoxy the wing mounting blocks in place.
b. Glue lengths of 3/4" triangle stock to the top and front of the wing mounting
blocks.