25. Locate the position of the maple blocks either side
of W4. Mount the control horns on each flap section
and gauge the angle to the block. Drill the block at
that angle, and install pushrods into the blocks.
Connect with clevises to the control horns. We will
adjust them in a moment.
Functional flaps:
Mount the control horn for the inner flap section. Connect
the bellcrank and control horn for the inner flap section with
a pushrod and clevis. Mount a control horn to the outer flap
section at an angle pointing slightly aft of the bellcrank link-
age. Attach a clevis and pushrod to the control horn and
bend the pushrod until it is parallel to the inner flap pushrod.
Mark this location, remove both pushrods, and solder them
together. (Scuff the puhsrods with sandpaper; find a piece
of old automotive wire, and peel off the insulation and save
a few strands of the wire. Wrap the pushrods with the wire
and then solder; the joint will outlast the airplane!)
Now let’s adjust everything: using the W4 (flap) and W8
(aileron & flap) incidence gauges provided, start with the
ailerons. Connect the pushrod and servo and center the
servo. Mount the W8 Incidence Gauge to the wing (top) at
the inner end of the aileron and adjust the aileron to match
the guage (if your aileron doesn’t quite match the contours
of the gauge, that’s OK. Eyeball it, because this is prelimi-
nary) repeat for the other aileron. Connect and center the
flap servo. Use the W4 Incidence Gauge to set the outer
flap section. The flap and aileron should be even with both
centered. Adjust the inner flap section to match the outer.
1. Glue F25 Cockpit Bulkhead to the top of F4A and
angle it to match the rear of the forward sliding
canopy.
2. Finish the interior as you wish. An instrument panel
is provided on the 3-view drawings; cut it out, and
glue it to the back of the pre-cut balsa panel, and
glue in place. Add pilot figures, etc., to suit. A rear
machine gun may be added. Note that a portion of
the rear cockpit floor is relieved to allow the servos
to fit. You may build up this area with scrap balsa if
you desire.
3. Glue the canopy in place.
Final Assembly
20. Starting with the ailerons, epoxy the hinges in
place. Don’t go overboard, but don’t skimp with the
glue.
21. Bevel the edges of the outer and inner flap sections
to allow a flush seam, and epoxy the outer flap sec-
tion in place. Verify that the flap and aileron ends
are even.
22. The inner flap section hinges do not attach to ribs.
Locate the slots by test fitting and comparing with
the outer flap. Maintain the same distance with the
wing trailing edge, and epoxy in place.
Test fit each control surface, and trim until, with the hinges
locked in place, the control surface pivots freely and does-
n’t interfere with the wing.
23. Mount the control horn for the aileron directly aft of
the linkage, and mount the horn on the aileron so
that the screws do not interfere with the wire
trapped inside. Connect the aileron linkages and
adjust.
24. Each flap section uses it’s own control horn. Do the
following for fixed flaps:
15
