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discs fitted to an Alan Gibson wheel. It's not quite big enough to reach the rim, even
upside-down, so three short bridging lengths of PhB wire have been soldered in.
A disadvantage of the solid disc is that the
connection with the axle can be lost as the
hole in the disc becomes a looser fit on the
axle as the wheels are removed and replaced.
The flexibility of the Brassmasters type avoids
that
disadvantage (as it can be distorted
slightly to ensure that at least one edge is
bearing firmly against the axle), but the fixing
to the wheel rim is more prone to failure. We
have had some success with using thin shim of
copper (from the sheathing of satellite coax
cable) soldered across the hole in the solid
disc, to be punched through when the axle is
fitted. The shim can be replaced when necessary.
In the following we refer to 'outer', 'centre' and 'inner' axles. On each bogie, the
outer axle is that nearest the coupling end. The inner axle is at the end of the bogie
towards the middle of the loco, with the remaining centre axle being the one in between.
On the Bearing Carriers (C1) and Subframe Mainframes (S4) the inner axles are indicated
by a single half-etched dot, the outer axles by two half-etched dots (see the
instructions for a full explanation of the marking system).
Dismantle the Bachmann OO driven wheelsets. Recover the final drive gears and the
axle bearings. Discard the wheels and axles.
Press the gear muffs on to the replacement 2mm driving axles, centreing them in
position.
The Bachmann axle bearings need to be opened out to accommodate differential
movements of the axles in the suspension whilst at the same time holding the drive
gears in mesh and transmitting the tractive forces from the drive train to the axles.
Open out the internal diameter of each of the Bachmann 2mm axle bearings to about
2.2mm.
We found that the tapered end of a 2.3mm cutting broach was about 2.1mm diameter
so used that to cut half way through the bearing from each side, finishing off with a
smooth broach. Not a technique for the purist, perhaps, but adequate for our purpose.
Alternatively, using a lathe, we have simply drilled through the bearings.
The following operations check the differential movement between the drive train
and the bogie subframe. Repeat them for each bogie in turn.
Collect together the Drive Unit, brass bogie Subframe, Bearing Carriers, axles and
Bachmann axle bearings for the bogie.
Bachmann 'Peak': Wheelsets
53/65
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27/09/2021
Содержание PK017
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