Great Planes PT-40 MkII Kit - GPMA0118 - Manual (Page 32)

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2. Turn the wing upside down. Position the trued edge of
one of the 1-1/2" wide sheets you just cut against the
leading edge of one of the wing panels at the R3 rib
nearest the root. Use a ballpoint pen to mark the “step” in
R3 at the aft edge of the bottom forward spar.
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3. Do the same for the other end of the sheet at the R3
rib nearest the tip.
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4. Use a straightedge to cut the skin slightly wider than
the lines you marked (it’s easier to remove material than it
is to add it). Test fit, but do not glue, the forward bottom
wing skin between the leading edge of the wing and the
notch in the ribs. A little too wide? No problem. Just use
your straightedge to strip a little more off and test fit again.
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5. Use the same procedure to fit, but do not glue, the
other 1-1/2" wide sheet to the other wing panel.
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6. Test fit the sheets so they join at the center rib, then
trim the ends so they are flush with the outside edge of the
tip ribs.
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7. The sheets should temporarily stay in the wing without
any glue. If needed, use a few pieces of masking tape to hold
the sheets in position while you proceed to the next steps.
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9. Turn the wing upright and carefully place weights in
the center. Prop up each tip by placing the die-cut 1/8"
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8. If you are building the SPORT WING, modify the
washout jigs as follows: Use a straightedge to draw a
line through the punch marks on both die-cut 1/8"
plywood washout jigs, then use a razor saw to cut along
the lines you drew, separating the tops from the bottoms.
Glue two pieces together so the bottoms of both parts
are even as shown in the photo. Hold both of the jigs
together to make sure they are identical. If they are not
identical, use a sanding block to even them up.
EXPERT TIP EXPERT TIP EXPERT TIP
32
Do not attempt to cut the sheet with only one pass of the
knife but make several passes, deepening each cut as
you go. This will enable you to actually strip the wood by
cutting, not splitting, the wood. This provides a smooth,
straight edge instead of a jagged edge.
SKIP STEP #8 IF YOU ARE BUILDING
THE TRAINER WING (A-WING)