with a little thick CA. Finally glue the phenolic ‘U-
shaped’ plate under the slot in the fuselage ply plate
and use this to adjust the final canopy fit at the front.
Filing the slot at a slight angle to match the phenolic
hook gives the final fine adjustment to make sure the
front of the frame cannot lift up from the fuselage.
If fitting the 2 plywood tongues, instead of the hatch
catch, proceed as follows:
Fit the canopy frame to the fuselage, tape into position
accurately, and cut 2 slots thru’ the frame and fuse-
lage, 3.5mm wide x 20mm long, and with the outside
edge of the slots about 4mm from the outside of the
fuselage. The slots should be about 50 - 70mm from
the back of the cockpit.
Glue 2 of the milled ply squares (20 x 20mm) inside
the fuselage, exactly under the 2 slots, at 90 degrees
to the flanges around the cockpit opening, using a
thick mixture of 30 min. epoxy and micro-balloons, as
shown in the photo. You can taper these squares a bit
for a good fit against the angled fuselage sides.
Transfer the position of the holes in the milled plywood
tongues to the squares in the fuselage, and drill
through the fuselage sides and the ply squares Ø
3mm for the bolts.
Extend the length of the slots in the fuselage flanges
only, backwards, by 6 - 8 mm to allow the canopy to
slide backwards and disengage the front hook.
Carefully wax the area around the slots on both the
canopy frame and fuselage in case some epoxy gets
on there in the next steps.
Fit the M3 T-nuts into the holes in the milled plywood
tongues, and bolt them in position with M3 x 16mm
bolts, with the tabs projecting up through the slots in
the fuselage flanges.
Fit the canopy frame again, and tape firmly in position.
Glue the tongues into the canopy frame using a thick
mixture of 30 min. epoxy & microballoons. Cut off any
excess length above the canopy frame afterwards.
If you chose to fit the hatch-catch, then proceed as fol-
lows: Use one of the milled ply squares (20 x 20mm)
and file a half-round slot in the top of it for the catch.
Apply a little light oil to the mechanism of the hatch
catch to prevent it being glued together. Tack the catch
place on the plywood with CA, and then secure with a
good fillet of epoxy on both sides, as shown. Taper the
Composite-ARF Extra 300L
(2.12m/84”)
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