15
Actual Size
Control Horn
20mm Threaded
Screw (4)
Actual Sizes
Locations of the control horns
❏
16. Notice the locations and alignment of the
control horns in both the photo and the illustration
before marking and drilling. The rudder control horn
must be on the left side. The elevator horn must be
underneath and on the right side.
The control horns should be
positioned so the holes are lined
up with the hinge line as shown in
the sketch.
Attaching the rudder control horn
❏
17. Position a control horn as shown in the
previous step, 7/8" (22 mm) from the bottom of the
rudder. Mark the two holes with a felt-tip pen.
Attach the control horn
❏
18. Drill two 3/32” (2.4 mm) holes straight through
the balsa rudder at the marks. Place a drop of thin CA
into each hole. This will add strength to the balsa.
Redrill the holes to remove any excess glue. Insert two
2 x 20mm machine screws through the control horn,
rudder and finally screwing them into the control
horn back plate on the opposite side of the rudder.
Tighten the screws but do not crush the balsa. Cut off
the excess threads that stick out using a wire cutter.
Install the elevator horn
❏
19. Attach the elevator control horn in the same
manner as the rudder. Place the control horn on the
bottom side of the elevator 1-1/8” (28mm) away from
the fuselage side (see previous photo at earlier step).
Mark the two holes with a felt-tip pen. Drill two 3/32”
(1.6mm) holes straight through the balsa elevator at
the marks. Place a drop of thin CA into each hole.
Redrill the holes to remove any excess glue. Thread
two 2 x 20mm machine screws through the control
horn, elevator and finally into the control horn back
plate on the opposite side. Tighten the screws but do
not crush the balsa. Cut off the excess threads.
Locate the rudder exit hole
❏
20. The rudder pushrod exit is located on top of the
fuselage on the same side as the rudder control horn.
Locate the exit hole using the measurements on the
sketch. Cut out the exit using a hobby knife.
Rudder Control horn
7
/
8
”
Fuselage centerline
Elevator control horn
1
1
/
8
”
Bottom of rudder
