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Composite-ARF Yak 55 (2.1m/83")
techsupport@composite-arf.com
the fuselage to account for the thickness of the T-nuts.
Make up the 4 blocks that will be glued in the fuselage
using the milled 3mm plywood squares (20 x 20mm)
supplied, exactly underneath each slot a shown. It is
important that the inside surface of the blocks is per-
pendicular to the fuselage flanges. The back two
blocks only need a little sanding to achieve this, but for
the front two you will need to use double thickness ply-
wood squares, and sand the outer surface to an angle
to match the fuselage shape. The inner surface of
each ply square should be exactly flush with the outer
edge of each slot in the fuselage flange. Tack glue in
place with thick CA, and then secure afterwards with a
thick mixture of 30 minute epoxy and micro-balloons.
Drill a Ø 4mm hole thru' the centre of each square,
and the fuselage side. Open up the Ø 4mm hole in the
4 milled plywood tongues provided (20 x 30mm) to Ø
5.5mm, and secure the M4 T-nuts into the holes with
a little thin CA. Carefully wax the area around the slots
on both the canopy frame and fuselage flange, in case
some epoxy gets on there in the next steps.
Bolt the 4 tongues in place in the fuselage with the M4
x 16mm bolts, so that they project up through the slots
in the fuselage flange as shown in the photo (right).
Refit the canopy frame onto the fuselage, taping it in
place exactly, so that the 4 tongues stick up thru' the
slots you filed in it. Check canopy frame alignment
carefully and then glue the tongues in the frame using
just a little very thick 30 minute epoxy and micro-bal-
loons mixture. Be careful that the epoxy doesn't seep
thru' the slots and glue the frame to the fuselage ! When cured, remove the canopy frame and
reinforce all the joints with some more epoxy/micro-balloons mixture.
Finally you can counterbore the Ø 4mm holes in the outside surface of the fuselage a little, so
that the boltheads sit almost flush with the surface.
To make sure that the sides of the canopy match perfectly with the fuselage shape you can add
2 additional small plywood or phenolic sheet tabs in the middle of each canopy flange, as shown,
and file matching slots in the fuselage lip (phenolic strip is included in the hardware bag).
Now glue in the clear canopy. Sand the inside edges of the canopy frame carefully with 120 grit
sandpaper, especially the fibreglass joining tapes, to ensure a perfect fit of the canopy. Fit the
canopy frame onto the fuselage. Lay the canopy on top of the frame, view from the front to check
that it is centred and symettrically positioned, and then mark the approx. shape with a felt pen or
wax crayon. Trim the canopy approximately to size so that it is about 6 mm bigger than the edges
of the frame. When the canopy fits inside the frame, tape it into position temporarily, check that
it is aligned properly, and accurately mark the edge of the frame on the clear canopy. Remove
the canopy and trim exactly to shape, leaving about 6 - 7mm overlap outside the line all around.
Unless you are in a warm room, we recommend that the canopy is slightly warmed up with a hair
dryer to prevent cracking - but be careful not to melt or deform it!
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