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Topics
Bolsters
Bearing
surface for trucks
Critical measurements
Floor to pedestal
Wheel flange to car side
Real world vs model
Trucks
Use
RP-25 brass wheels
Check with track gauge
Select
wide bearing surface
Remove
burrs
Screw hole and aduacent surface
Critical
measurements
Rail to pedestal may differ between types of trucks used
Remove
screw slop
#2 x 3/8 screw optimal
Use #2 washer in countersunk hole of truck
File OD so washer just fits
hole
File ID so washer pivots on screw
Tighten screw
Check under each
wheel to insure enough play
Polish
wheels for “running” look
Assemblilng couplers
Remove
burrs
Use
graphite
Thread
springs and glue in place at one end
Check
for height using guage
Understand that type of draft
gear used
Will affect coupler height
i.e. using MKD#4 in metal pocket vs
plastic universal pocket is different
Shim trucks with washers
Remove stock from top of bolster
Add
ship under coupler
Weight each car as required
How much
should car weigh?
To
little and the car is more likely to derail
To
much and needless drag will me few cars behind the engine
NMRA
recommended practice is oz plus ˝ ounce for every inch of car length
That is the
TOTAL weight of a car
What
has to be determined is how much extra weight do we need to add?
How much do
the required trucks, couplers etc weigh
Include and metal fittings such as end sills
Also, take
a guess at weight of wood, paint and any other items
Subtract
the above to determine weights required
Determine
what to use
Lead
is relatively cheap, heavy and commonly found
Not strong
Cerro
bend (Woods metal) low melt point alloys expensive but easily molded
Copper pennies cheapest but require more room
Tungsten is heaviest in raw form
but most expensive and little better than lead when used with
binders
brass
is cheap and easy to get
not as heavy as lead
strong and relatively easy to shape
most suitable for this project
select
brass with thickness approximating car floor
width must be narrow enough to fit between sides of car
length between truck bolsters
for a 42’ 50 ton flat car this would be nn x nn x nn
this is
not heavy enough
a second shorter section will inside belly of car sides
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