Retractable Undercarriage, Main Retract Units - GRAUPNER heim Bell 230 Instructions D'utilisation

Bell 230
Glue the two wooden lugs (A25) to the cross-piece as shown in the drawing, then hold the strut
exactly in its original position on the fuselage. Clamp the parts together, then drill 1.5 mm Ø
pilot-holes through the lugs (A25) and the fuselage at the marked points. Carefully open up the
holes in the lugs only to 2.2 mm Ø. Cut two small pieces of scrap wood about 8 mm long and
glue them under the screw holes in the fuselage. The cross-strut can now be fixed in place
again by fitting a 2.2 x 9.5 mm self-tapping screw on each side.
The screws and wooden lugs are hidden by the top fuselage fairing, and the front cut lines by
the front screens which are installed later.
Cut through the bottom of the vertical strut between the front screens, as shown in the drawing.
Glue the wooden lug (A24) to the inside of the strut, projecting by about 8 mm at the bottom.
Clamp the strut in its original position, and drill a 1.5 mm Ø pilot-hole through the bottom part of
the strut and the lug. Open up the hole in the strut only to 2.2 mm Ø, and fit a third 2.2 x 9.5 mm
self-tapping screw to secure it.

1.3 Retractable undercarriage, main retract units

1.3.1 Assembling the undercarriage legs
The retractable undercarriage consists of three identical leg units which are assembled as
follows: start with the main leg, fitting the spring (F22) on the moulded-in spigots between the
two arms (F23). Fix the arms together with two M2 x 10 screws and M2 nuts. Join the wheel
shells (F40) in pairs - one male, one female - and apply a few drops of cyano to hold them
together.
Fit one threaded sleeve (F19) in the fork
sections (F20), and the second sleeve (F19)
through the wheel hub. Join the fork sections
by screwing four M2 x 8 screws into the
threaded sleeves.
The next step is to join the main leg to the
wheel fork; note that the spring must be
tensioned before you do this. Hold the wheel
fork over the main leg with the 2 mm Ø holes
lined up, and push the dowel pin (F9)
through the holes to act as pivot shaft.
1.3.2 Fitting the buffers
Glue the two wheel fork buffers (F30) to the undercarriage legs as shown in the drawing, using
cyano. Note that they must rest on the flat surfaces, butting up against the shoulder of the
undercarriage leg at the top. As shown in the drawing, press the wheel fork against the spring
tension as far as it will go, and hold it there while the glue sets.
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