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These are all the parts it takes to put
the fuselage back together again other than the frame. At this
point I hadn't taken
the fabric off the wings yet so the few moving parts in them are not
included here. The top image starts at the bottom with the
spacers from the canopy frame then moves up to the nose area faring
pieces that give the fabric covering a smoother shape. Next
are the tow release, spoiler and elevator trim cables along with a tub
of miscellaneous pulleys and other small parts. There are many
bags of nuts, bolts and the parts they attach. The long tube at
the left is the control stick torque tube that will connect to the
elevator and ailerons. At the top you can see the chromed control
stick, nose
bulkhead, rudder pedals and all the tubing that provide the fairing for
the fabric around the cockpit and nose areas. The bottom image
includes the instruments, push rods, brackets, control horns, rear
fuselage stringer attachments and, the nose and tail cones. Some
of the parts have already been cleaned and given a prime coat to
prevent rusting until the final epoxy based primer was sprayed to seal
everything up.
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The
starting point once everything was removed for refurbishment was
building a new set of canopy rails. Normally these would be an
extension of the cockpit belly pan, but the crash this sailplane
experienced in the early 1960s destroyed this area so my father simply
made substitute rails out of angle aluminum. Over the years
these had become very corroded and needed to be replaced. The old
ones were used as templates to locate the holes where they are cherry
riveted to the main longerons. This was very time consuming and
required a lot of planning to make sure they fit properly so the canopy
would line up with the cockpit turtle deck area right behind it. The
left rail (right side of image) is the hinge attachment side since the
pilot enters the cockpit from the right side of the aircraft. The
black spaces in the other rail are where the latching fixtures are
installed. The wing carry-thru was also temporarily bolted in for
the wing fitting and alignment of some other control system parts.
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This
is an example of fitting the cockpit turtle deck rail to the angled
piece that integrates it into the cockpit rail. Again,
this is a critical joint since it must match the canopy framework,
which was also going to get an extensive work over (see below).
You can see
some of the corrosion on the original rails in the lower right corner
of the image. Eventually, after a lot of trial fittings, the
angled piece got drilled but not riveted to the rail. The final
installation would have to wait until the finished rail was riveted to
the longeron since they required the cherry rivets, whereas the angle
could be installed with regular rivets. This was a good example of the
need to work slowly and plan many steps ahead in order to eliminate
having to back track by taking out rivets that creates its own problems.
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The
top image is the aft fuselage turtle deck stringers with the bulkheads
temporarily bolted to the fittings so everything can be glued up.
The holes below each stringer were meant for string that would go
through slots in the stringer to hold them in place while the glue
dried. We decided to use pins to hold the stringers in position
while the epoxy setup and this worked well. The bottom image
shows a much larger fairing piece made out of 1/64 th plywood
from the local hobby shop. You can see the difference from the
original rebuild picture in the previous section. It came to me
with a
black plastic material as the fairing, but we found Poly Tak would melt
this particular type of plastic so wood was
the best choice from an attachment (gluing) standpoint to the stringers and later for the fabric covering. The whole
thing was then taken off the fuselage and given a good coat of aircraft
grade varnish that will stand up to the Poly Tak's MEK based
solvents. I learned quickly to always do test samples where
dissimilar items are coming together to make sure they are compatible.
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The
top image is the latching side of the canopy frame. It looks
very messy and in fact had significant rusting so it and the other main
canopy frame rails had to be replaced. I also replaced the long
tube that holds the parts that actually go into the brackets build into
the fuselage rails shown above. This was easier than trying to
clean the corrosion and rust out of the original one. I was lucky
to have a great metal works shop in the hangar next door and they made
quick work of the elongated holes that contain the latch mechanisms
handles. This new tube eventually got brazed onto the new frame
piece just as it is shown on the drawings. The bottom image is
the other side of the canopy where the hinges are attached to the
frame. They were corroded and the steel tube also rusted beyond
saving.
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This
is how I went about fixing the problem. The jig was build on a
solid foundation using the original canopy frame since it must have fit
the fuselage rails in the past. They may be hard to see but there
are a number of small "L" shaped brackets along both sides of each
frame piece to hold the new square tubing in exactly the same position
for welding. The wood pieces on each end hold it down against the
table, which is a $3 piece of scrap from the Home Depot aircraft supply
store and placed across saw horses. The vertical pieces were
designed to hold the hoops at the proper angle to match the front
instrument panel bulkhead and the rear turtle deck bulkhead
framing. This is all done before the old frame pieces are cut off
the hoops. You can see the latch tube has been cut off at this
point since it was attached to the bottom of the right frame and would
have made it impossible to build the jig. You can also see the
new latch tubing and the new square frame tubing that will be installed.
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The
main concern when cutting the hoops off the rails was retaining the
proper height of the front and rear
hoops since they had to match the cockpit turtle deck that didn't need
any rebuilding. The metal shop owner said to put a mark on the
hoop about an inch up from the rail then measure the distance from the
mark to the rail to establish a base line value for each corner.
Then cut off the hoops vertically through the rail on either side of the joint instead of trying to
cut it flush with the rail with a cut off disk. Now you just grind
off the excess rail material until the end of the hoop tube is the base
line distance from the mark. I wrote these numbers down on the
jig so they were always available during the grinding and
measuring. The expert welder in the shop then reattached the
hoops to the new rails and you can see the canopy fairing and old
canopy fit very nicely. Again, this was all very time consuming
and I was lucky to have people next door to assist.
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This
image is a little deceiving since it looks like a rudder cable is going
around a corner. I merged two images to show what the two cable
guides looked like from the same angles on each side. They are
Teflon versus wood but you can see they are constructed
differently. I think what happened was dad ran out of enough
large pieces to cut out the one on the right so it matched the
left. He stacked some smaller pieces together to make up the
bottom of the right guide as can be seen from the screw head along the
bottom edge. The problem was resolved by picking up a scarp piece
of Teflon from a local plastics distributor that had some holes in just
the right places. I cut some slots and trimmed a little here and
there to come up with one that matched the left image. These
shots also show the installation of the arm rests
and the oxygen regulator mounting. I have put a flat plate on the
mount and Velcroed a Mountain High oxygen controller on it to save
space for my knees.
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Now
that all the black primer has been removed from the nose cone bulkhead
I have started fitting the elevator trim cabling. The fuselage
is upside down at this point so for the experts it really isn't mounted
backwards. I found I could make good use of adele clamps to help
hold the cable housing in place and the one on the mounting bracket
(bottom image) allowed for an improved angle that freed up the cable
movement. The black vertical piece is the shield for the tow
release cable that dad installed in place of the original aluminum
tube. He also installed aircraft grade pulleys at the top and
bottom of this shield for the release
cable to eliminate the friction. You will see other examples of
where he reduced friction though the use of Teflon or ball
bearings in the fuselage and wings.
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