Golden Era Model Service
High Quality Plan Sets for Radio Control Aircraft
Henry Struck's 1937 Benny Boxcar

Servo installation. The servo arm is outside the fuselage on the elevator servo, like a Ford Trimotor. Drag from the Kevlar control runs is minimal.  Rudder
servo is right on the back of the firewall.  You can see one of the corner gussets at the top of the fuselage.  Make sure you angle them down to clear the
center of the wing as shown on the plan.  I make the loops in the Kevlar with 4 or 5 square knots and then drop some thin CA on the knot, wicking
 the excess CA off with a paper towel so it doesn't run down the line.  Perhaps it would be better to use a wire loop to attach the Kevlar to the servo
arm so there is no relative movement on the Kevlar when the arm rotates.  I haven't seen any fraying yet.

 
Tail assembly.  A steel pin through a G10/FR4 fitting.  Templates are on the plan for the fittings and control horns.  
The elevator is covered and the pin is inserted from the end and a bit of covering or white glue secures the pin.

This is the center elevator pivot.  Another G10/FR4 fitting that sides into grooves on the stabilizer spar and glued with CA.  The little ply block in front holds the
carbon fiber carrythough in position against the fitting.   Note the other little blocks about the centerline on the back of the stabilizer spar.  The fin rear spar
 fits between them.   The notch toward the front of the stabilizer in the center is for the front fin spar.  The photo shows the slot for the elevator control horn on
the right side but that is because in this photo the elevator is upside down.  In final assembly the control horn is on the same side as the pivot fitting.  
 
 


The tail assembly is removable on the prototype.  The aft fin spar continues to the bottom of the fuselage and is trapped between the sideframes.  The forward fin
spar goes through the notch in the stabilizer and also continues through to the bottom of the fuselage.  Balsa shims are installed inside the longerons to maintain
 a center position.  A 2-56 rod goes through the fin lower rib and the stabilizer, and then through a 1/32 ply plate on the bottom of the fuselage.  In final assembly
 a self locking nut is used, not the plain nut shown.  Note   the ply doubler under the bent portion of the rod on top.  Thick CA glue holds the rod to the ply and the
 end of the rod is also bent down and is stuck into the balsa.  The screw retains both the fin and stabilizer.  On the rudder a slot has been cut to receive
the control horn.  The top rudder pivot is steel pin with a companion hole in the  rudder.  The ply plate on the bottom of the fuselage is the lower rudder
pivot, a screw is used there.  The bottom of the rudder has balsa fairings to match the fuselage contour.

 
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