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Fit the plates together as shown (there is
no need to solder them together), making
sure that the larger holes are opposite each
other, and that the assembly is square.
Orientate each Drive Plate assembly with
one of the smaller ends of the Drive Units.
Slide the taller part of the Drive Plate
assembly into the end of the Drive Unit and
pin it in place with two of the idler axles.
Taking the three remaining idler gears, thin
dow n their widths over bosses such that
they are a free fit between the Drive Plates, a
dimension of about 2.3mm. There may be a
small moulding pip on the side of the gear
whic h should be removed. Ensure that the thinned gears each rotate freely on the idler
axles.
The bosses of the plastic gears can be
thinned by filing them down, and/or paring
off with a very sharp knife. To hold the gear
while working it, clamp one of the idler axles
into a collet pin chuck with about 2.1mm
projecting. The gear can then be placed over
the axle and worked with the file or knife while
holding the pin chuck in the other hand.
Filing will leave 'fuzzy clods' of deconstituted
plastic around both the outside edges of the
bosses and the axle holes. It is essential that
this waste is removed, using a sharp scalpel
blade, as the smallest amount will cause the gears to run tight on the axles or bind
against the Plates. Use the scalpel to put the tiniest of bevels around the circumference
of the axle holes and outer edge of the bosses. Finish cleaning with a wash of methylated
spirits scrubbed by an old toothbrush. Do not be tempted to relieve the axle holes with a
broach or reamer - any tightness will be down to dust or swarf.
Bachmann Class 66: Modifying the Bogie Drive
31/60
(c) PenBits Model Railways, All Rights Reserved
27/09/2021
Содержание Bachmann Class 66
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