Page 47 - Rail Express - September 2019

MODELLING
be located. Mark in acentreline first
and then draw round the fins of the
coupling armmoulding to determine the
minimum sizeofthe opening.
Using a2mm drillinapin-vice, drill
arow of holes around the inside of the
lines and then push through using a
modelling knife. File the hole to shape, it to spring back into place. If it is
using the arm moulding to achieve the
same curved sided shape as seen on
the underside of the donor wagons.
Whilst filing and cleaning up the hole, If thearm moulding catches and won’t
checkprogress with acompletely
assembled coupling cam untilitfits
neatlyand with its leading edgeup
against the rear of the headstocks.
Installation
On theupper surface of the coach
underframe, apiece of 20-thou black
styrene cardwas fitted overthe
opening to hold the arm moulding
in place. Afilling pieceofthe same
material is required to pack out
the space to ensurethe arm works
smoothly. Once completed, the coupling
camassemblyispositioned on the
underside of the underframe moulding,
centredasaccuratelyaspossible and
¬ The assemblyisoffered up to the
underframe and centred as accuratelyas
possible to allowthe screwholes (A and
B) to be drilled.
¬ Dry graphite lubricant is used to ease the side to side action of the moving coupling Youcan make your owntomeet
arms in the cam assembly. The stiff centring spring does the rest.
¬ The finished result is both neat and reasonablyunobtrusivewhen used on the Lima The underframe waspackedtothe
air-conditioned coach models. Rudd coupling cams work well, spacing the gangways correctheight with pads of 20-thou
apart to prevent buffer and gangway locking when the coaches run through curves. black styrene cardand newcouplings
Supplement No. 185
three screwholes drilled in place with a
0.7mm diameter drill to match those in
the cam assembly. The three retaining
screws are‘self-tapped’ into the screw
holes to secureeverything.
Thecam is tested by moving it to
one side and then the other,allowing
too slack in the frame, remove the
assemblyand pack the oversizearea
of the opening with strips of styrene.
¬ An opening to accommodate the ¬ The opening is shaped to allowthe fins
return to the straight position, check moving coupling arm moulding has to be on the coupling arm to move freely.
the openings fortight spots or burring, cut into the underframe.
including the packing piece.
To smooth the action, use adry
lubricant such as Kadee‘Grease-em’
sparinglyinthe cam mechanism.
Interestinglyenough, the spring centres
the cam arm well,but is alittle fierce
in its action forthe original wagons.
It worksbetter in heavier long frame
vehicles such as coaches and it should
be retained as it holds the arm in place
in the cam assembly.
Fixed coupling bars
Once happywith the action of the cams
nowtheyare locatedintheir newhome,
choosing couplings comes next.
The NEM coupling pocket happened
to be positioned at the correct height
when used on Lima coaches with the
particular wheel and ReplicaRailway ¬ Asimple bar coupling can be made up of 60-thou styrene forfixedrakes, tapered at
bogie combination used in the original the ends forafirm push fit to the coupling boxes.
coach rebuilding project. Thereisno
doubt that some adjustments to the
positioning of the cams mayberequired
formost projects to achieve the correct
height forthe NEM-362 pockets as
stated in the MOROPstandard. It's
necessary fora compatible coupling
system and to makethe close coupling
cam installation compatible with any
collection.
If thecoaches aretobecoupled in
afixedrakeorportions of arake; or the
inner ends of EMU trailers, the height
of the coupling pockets maynot be
as vitalfor the inner couplings as long
as they arethe same height as each
other.However,a proprietary NEM-362
uncoupling system cannot then be
used because theyrequirethe coupling ¬ The gapbetween thegangwaysisclosed up on straight track. Note the NEM
boxestomeet the MOROPspecification coupling pocket (A) and coupling bar (B).
forheight from the rail,makingbar
couplings abetteroption. fittedusing replacement NEM-362
pocketsfitted to Parkside Models PA34
your needs, of course. Simple bar mounting blocks. Alternatively, one
couplings of 60-thou black styrene cansecurethe original tension lock
were used on the featured models, cut couplingsdirectlytothe underframe
to awidth of 4mm –slightlywider than with screws wheretheyshould work
the inside dimensions of the NEM-362 perfectlywell. As forthe modified
coupling boxes. Coupling bar length stock, the newcam mechanisms and
depends on the minimum track radius couplings will have to be weathered
of thelayout on which theyare to in to suit the rest of the coach
operate. Once the minimum length was underframe.
determined to avoid buffer lock and
with 8mm allowedateachend to slot Afinalthought
into the coupling pockets, the coupling What would asuitable alternativetothe
bar ends were chamferedtoabout 3mm Hornbywagon coupling cams be if you
in width forapush-fit firm enough to do not have acollection of Rudd, Tope
keep the coaches coupled together. andClam wagons?Thereisanexcellent
closecoupling cam system which will
Finishing off work just as well, produced by Symoba
To complete theproject, the donor (alsoavailable underthe Gützold name).
Rudd, Clam and Tope wagons were The system is complete with coupling
fitted with newcouplingmounts. bars,adjustableNEM pockets and
closecoupling (kinematic) assemblies.
Symoba products areavailable through
DCCSupplies (www.dccsupplies.com).
September 2019 RAIL EXPRESS Modeller M15