GRAUPNER Heim Eurocopter Bo 105 CBS Mode D'emploi page 61

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Bo 105 CBS
Cut out the ABS stabiliser shells along the marked lines and sand the edges carefully so that
the shells fit together perfectly: the stabiliser panels and the tip fins are identical right and left;
the horizontal stabilisers have mirror-image top and bottom shells, and the tip fins an inside and
outside shell. The outer shells feature a five-cornered marking indicating the position of the
navigation lights (the peak of the pentagon faces the rear), and the inner shells feature a
rectangular marking indicating the slot into which the lug of the horizontal stabiliser panels
projects when the tip fins are attached later. These slots must be cut out at this stage.
Sand the tip fin shells to fit together neatly, then tape them together and run thin cyano through
the rectangular opening, allowing it to run along the seam on the inside. Turn the part round
through 360º several times to distribute the glue thoroughly. Remove the tape when the glue
has hardened, and sand the outside of the joint line with fine abrasive paper.
Before gluing the horizontal stabiliser shells together, cut the holes in the end faces to accept
the carbon fibre rods. The completed panels have to be glued to the CFRP rods with epoxy, and
this is made possible by sanding the inside surface of the stabiliser shells with fine abrasive
paper and applying a coating of thin cyano to the plastic.
Note: it is widely known that epoxy resin does not adhere properly to ABS; the only 2-pack
adhesives which are effective are polyester-based (Stabilit express); on the other hand epoxy
laminates, including CFRP rod, cannot be glued successfully using polyester-based adhesives.
However, if you apply a coating of cyano to the ABS parts, the cyano adheres very well to the
plastic, and this layer can be bonded satisfactorily to the CFRP rods using epoxy glue (e.g.
UHU plus endfest 300).
As with the tip fins, tape the shells together and glue them using thin cyano applied on the
inside. When the glue has set hard, sand the edges and joint lines smooth; the tip fins can then
be fitted to the tips and glued in place exactly at right-angles using Stabilit express or cyano.
Slide the completed stabiliser panels onto the carbon fibre rods as far as they will go, and
position them with the front and rear edges of the panels lined up exactly. Note that the
outboard end of the horizontal stabiliser panels is thinner, and the joiner rods must not force the
panels out of shape at this point; you may have to sand back the ends of the CFRP rods top
and bottom to avoid unsightly bulges.
When you are sure that everything fits correctly, glue the stabiliser panels to the joiner rods and
the fuselage using epoxy.
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