Sailplane Construction Article Session
I had to discontinue the work on the stab because
I needed to develop the fin structure to fit into the stab's center slot
before the stab's center section can be planked. The root of the fin will
have two plywood hard points embedded in it with 2-56 threaded holes for
securing the fin in the stab's center slot. This in turn will set the
placement of the two or three plywood cross pieces on the bottom of the
stab's center section to secure the stab to the fuselage stab platform, but
I am getting ahead of myself. All of this will be covered in reports later
The Sailplane's vertical tail has a 7-7/8" root
chord measured from rear face of the stab's main spar back to the trailing
edge. Using input from Nick Bruschi and Steve Rozelle as a guide,
I established the rudder's root chord at 3.0". Then I laid out the rudder's
hinge line and drew in the trailing edge of the fin. A piece of 3/16" X 1/2"
medium hard balsa was used for the fin's trailing edge and the width fin's
leading edge was also increased to 1/2" as shown below. Notice the two
pieces of 3/16" X 1/4" spruce strips used to reinforce the root of the fin
that will be in the stab's center slot. The large flat 3/16" piece at the
bottom of the fin is also part of the structural "plug" that will slide into
the stab's center slot.
I maintained the fin's rib and internal spar
structure as shown below. These are fitted in place, but not yet glued in.
You will notice on the plan below that there is a lower portion of forward
fin which integrates into the fuselage structure that I have not addressed
yet. I will have to work this out later as this is part of a rather large
fairing as the fuselage fairs back into the stab/fin forward structure
(see the schematic in the
upper left corner below).
This picture shows a trial fit of the fin's
lower structural plug inserted into the stab's center slot.
This shows a picture from the other side. There
is going to be a complex interface where the fin's root rest on top of the
stab's curved planked center section.
From now until Christmas, I am going to be kind
of overtaken by events. Sue and I have over 60 Christmas items that have to
be boxed, wrapped, and put under the tree for Christmas. We have several
Christmas parties to attend and then out of town guests will be arriving the
first of next week. I will still get a little building in, but all in all,
most of my time will be spent doing holiday things............Tandy
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