D 6. Trial fit the fin and rudder together using the hinges
to check for proper alignment. Do not glue the hinges in
place yet! Sand the rudder and/or fin so they match each
other at the top.
D 7. Remove the hinges from the rudder
and bevel the leading edge with your
sanding block as shown in the sketch. This
is to allow the rudder to swing either
direction once the hinges are glued in.
D 8. Add the 1/4" x 1/2" balsa doubler to each side of
the fin as shown in the photo above. Use a razor saw to
cut the excess off at the leading and trailing edges.
D 9. Check the fit of the fin assembly into the aluminum
channel. It will most likely be a little loose and we want
a nice tight fit. Add a strip of the 1/64" plywood doubler
to ONE side of the fin gluing it to the balsa doubler.
Check the fit again and if it is still a little loose, add a
plywood doubler to the other side. If you need to you can
sand the plywood slightly to help the assembly fit. Also,
you can have the covering material continue down over
the doublers if you need the additional thickness.
D 10. Position the fin assembly in the channel with the
trailing edge of the fin even with the end of the channel
and press it in place. Mark the location of the stabilizer
bolt holes on the bottom of the fin and then remove the
fin from the channel.
D 11. Wrap a piece of masking tape around a 7/32" drill
bit about 1/2" from the end of the bit.
D 12. Drill two holes in the bottom of the fin assembly
to make a space for the stabilizer bolts. Be careful not to
drill any deeper than the masking tape or you may punch
through the side of the fin.
6
