Carf-Models Ultra Lightning Instruction Manual page 27

Cockpit Frame and Canopy
The moulded fibreglass canopy frame has already been
trimmed at the factory, and the securing method completed
for you. It only remains for you to fit the clear cockpit canopy,
and optional plastic cockpit tub if you wish.
The cockpit canopy is held in place by a pair of phenolic
hooks at the back, located in the middle with 2 small pheno-
lic tabs, and secured at the front with a single M4 allen bolt
into a T-nut in the fuselage.
Fitting clear canopies can be a little bit tricky, but this is the
method we use: Sand the inside edges of the fibreglass
canopy frame (and especially the fibreglass joining tapes)
carefully with 240 grit sandpaper, to ensure a perfect fit of
the canopy inside. Lay the clear canopy on top of the frame,
and mark the rough shape with a felt pen or wax crayon. Cut
the outer border of the clear canopy with sharp scissors,
about 12mm (1/2") too big all around. When the canopy fits
inside the frame, mark the final cut line on the clear plastic.
Then cut it to exact shape with a 6 - 8 mm overlap all
around. Do this in a warm room to make sure that you don't
split the clear canopy.
Make several hand-holds with paper masking tape (see
photo) to make holding and positioning the canopy easy.
Push the canopy up tightly inside the back of the frame and
fix the bottom 2 back corners with one small drop of slow CA
each (ZAP-O or Plasti-ZAP recommended). Note: Do NOT
use any CA accelerator/kicker - you will immediately 'fog' the
clear canopy!
Visually check from the front and back to make sure sure
that the canopy is straight. Tape the front of the canopy to
the frame temporarily. Mount the canopy frame to the fuse-
lage and tape the top/back corner of the canopy frame tight-
ly to the fuselage. Using the masking tape handles to pull
the canopy outwards firmly against the frame, working from
the back towards the front, glue the edges of the canopy in place in 2 more places each side,
and to the fibreglass top hoop, with just a single small drop of CA at each position, all the time
checking that the edge of the canopy is tight up against the frame at the front.
Visually check from the front and back again to make sure sure that the canopy is straight.
Now that the canopy is fixed in position and cannot twist anymore, you can carefully glue the
rest of the canopy firmly in place. Continue to use CA (or your favourite canopy glue) around
the edges, allowing it to wick into the joint between the frame and clear canopy. When cured,
carefully remove the canopy frame from the fuselage and secure the clear canopy to the inside
of the frame properly with 24hr epoxy and micro-balloon mixture around all the edges on the
inside. Be sure that you make a good job of this, with careful surface preparation, so that there
is no risk of the clear canopy coming off in flight which would seriously affect the flying charac-
teristics of the plane.
(above) The front of the canopy is
secured with an M4 bolt, thru' a
plywood plate into a T-nut in the
fuselage - all factory finished!
(below) The canopy frame is
secured with 2 phenolic hooks
into phenolic plates in the side-
rails, and 2 location tabs.
(above) Make plenty of tape 'han-
dles' to hold the clear canopy in
place while gluing into position.
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