Installing The Mechanics - GRAUPNER Bell 230 Bedienungsanleitung

Bell 230
Now retract the noseleg unit. The nosewheel must also lock mechanically in the retracted
position, although in this case it is not essential that the pin (F3) should be right at the end of the
slot, because the loads are much lower; i.e. a slight space is permissible at the end of its travel.
The important point is that the leg should lock absolutely reliably in the extended position; the
mechanical linkage must be adjusted very carefully until you are confident that this is the case.
Once you have found the final position of the lever (F24), tighten one of the two grubscrews in
each of the two collets (F26) very firmly, then unscrew the other grubscrews and drill a 2.4 mm
Ø hole through the threaded hole and into the shaft of the lever (F24) and the aluminium tube
(F29). Apply a drop of thread-lock fluid to the grubscrews, then tighten them to the point where
they engage fully in the wall of the aluminium tube (F29). This will reliably prevent the lever
rotating on the shaft.
Check once again that the noseleg retract system works reliably and freely; it can then be
installed in the fuselage.
1.4.4 Installing the noseleg retract unit in the fuselage
The next step is to trial-fit the noseleg assembly in the nose of the fuselage. The nosewheel
should coincide accurately with the factory-cut opening, i.e. the wheel should extend and retract
through the opening without problem. You may need to adjust the opening, and you may also
need to trim the two longitudinal formers (A1) and (A2) to compensate for any irregularities on
the inside of the fuselage moulding. The formers must make good contact with the bottom of the
fuselage, without any projecting parts producing bulges in the fuselage shell. Set the assembly
exactly central, lining up the 3 mm Ø holes already drilled in the fuselage with those in part
(A11). Sand the inside of the fuselage floor as flat as possible in the area where part (A11) rests
on it, i.e. sand the central seam level with the rest of the fuselage floor.
The whole framework can now be glued in the fuselage shell using UHU plus endfest 300; apply
plenty of epoxy to the underside of part (A11) when you do this. Fit two M3 screws through the
holes in the fuselage moulding and part (A11), and fit nuts on the inside to hold the framework in
the correct position. Check once more that the noseleg unit extends and retracts reliably, then
leave the epoxy to cure completely.

1.5 Installing the mechanics

1.5.1 Bottom screwed joints between mechanics and fuselage
Glue together the small support plates A23 in groups of four to produce two blocks about 12 mm
high. Drill a 3 mm Ø vertical hole exactly in the centre of each block.
The rear mechanics support (A21) already features two 3 mm Ø holes.
Fit the four M3 x 30 mechanics retaining screws through the holes in the fuselage bottom, and
apply tape over them to prevent them falling out. Fit the blocks made from parts A23 on the front
two screws. Fit the 4/3.2 x 17 mm brass tubes on the rear screws, followed by the support plate
A21, fitting the lateral bulkhead A20 in the channels as you do so; note that bulkhead A20 has
not yet been glued to the fuselage. Now fit the mechanics in the fuselage and fit it over the front
screws first, then over the rear screws. Adjust the position of the mechanics until the main rotor
shaft exits the fuselage opening exactly central when viewed from the front. Tack together the
framework consisting of parts A7 and A20 with a few drops of cyano.
1.5.2 Upper bracing between mechanics and fuselage
Drill 2.2 mm Ø holes in parts A13R and A14L at the marked points and fix them to both sides of
the angled rear flange of the top fuselage opening using 2.2 x 6.5 mm self-tapping screws; the
outside of these parts should end flush with the flange.
Don't mix up the left and right parts!
Glue together the small support plates A24 in sets of three to produce two blocks about 9 mm
high. Glue the two brackets 3 to these blocks using cyano. Now screw these two assemblies to
the top mounting points on the mechanics by fitting M3 x 16 socket-head cap screws through
the clips; the blocks made from parts A24 should now rest against parts A13 and A14. If the
mechanical system is correctly positioned, they will rest lightly on parts A13/A14; you may have
to loosen the bottom retaining screws again and adjust the position of the mechanics by
trimming the bulkheads. Once you have established the correct position, fix parts A24 to parts
A13 and A14 with a few drops of cyano.
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