Walthers Cornerstone Series User manual

MODERN 130' TURNTABLE
HO Scale
Structure Built-up
933-2829
Thanks for purchasing this Cornerstone
Series®Built-up.
HISTORY OF THE TURNTABLE
Although we associate turntables with
steam locos, they’re still used in some
engine terminals. Requiring less space
than a wye or loop, they’re an econom-
ical way to reverse locos or cars. A
turntable is basically a large bridge
equipped with rails that can revolve in
a full circle. Around the turntable, a
series of radial tracks (other nicknames
were also used) run into roundhouse
stalls, open-air storage or service
tracks. So that all rails were at the
same height, the turntable was con-
structed in a large circular opening,
called a pit. Early pits were made of
earth or stone, while modern designs
used concrete.
The basic concept of the turntable
evolved before the railroad, when
crude examples were used to reverse
coal carts in mines. From the earliest
days, steam locos (as well as special-
ized equipment like snowplows and
observation cars) were built to operate
in one direction, and had to be turned
around for their return trip. By 1842, a
device we would recognize as a rail-
road turntable was in regular use in
England. Over the next century, the
turntable became a fixture of railroad-
ing around the world.
In America, three basic types devel-
oped. The first was the center-balance,
with a central pivot point and wheels
under each end of the bridge to support
the weight, but bigger and heavier
locos put too much strain on these
early turntables. The next was the
Articulated Design, with a central ver-
tical hinge, which allowed the table to
tip in the direction of the greatest
weight. The final type (still seen today
and the prototype for this model) was
the Continuous Girder, which supports
the weight on a center pivot and on
load-
bearing wheels under each end.
Two styles of turntable bridges became
common. These included the Deck
Style, with most of the bridge below
ground level (requiring a deep pit) and
the Through Type, where a portion of
the bridge was above ground.
In order to swing the table end for end a
source of power was needed. In the
early days, men pushed the tables, and
they came to be called “armstrongs,” as
it took strong arms to do the job! In
later years steam and gasoline engines
were used to drive one set of the load-
bearing wheels, but electric motors
were found to be the best choice for
most applications. Electricity was sup-
plied to most tables by an arch over the
center, connected to overhead power
lines.
In most terminals, the turntable and
roundhouse were in constant use. For
easier and safer operation, turntables
had a small operator’s cabin at one end
of the bridge. This housed controls and
placed the operator in the best position
to align the rails. Many also sported an
old engine bell, which was rung to warn
that the table was being turned.
As was the case with most engine serv-
ice facilities, new turntables were built
to accommodate the longest engines in
service on a division. For this reason,
some large engines were restricted to
one or two divisions where turntables
and facilities were big enough for them.
Railroads also went to extremes to uti-
lize existing turntables. Some ordered
new steam locos with short wheelbases
so they would fit, others extended
turntable rails, and some resorted to
jacking up the end of the tender!
With the coming of diesels, the need for
turntables began to decline. Although F
units still had to be turned, the new
roadswitchers and Geeps could be run
in either direction. Today, the number of
turntables on active duty is declining,
but those in use can be found at major
shops and engine terminals. A few are
also in use at railroad museums.
ON YOUR LAYOUT
This 130' table is typical of units
installed by most roads from the 1920s
on at division point terminals, where
engines were changed and serviced. It
will easily accommodate large articulat ed
steam locos and most diesels up to 18"
(45cm) long.
As bigger power came into service, big-
ger roundhouses were also required.
This can easily be modeled with the
Modern Roundhouse (933-2900) which
includes parts for three complete stalls.
It can be expanded up to a full circle
with the Modern Roundhouse Add-On
Stalls (933-2901) which includes
matching roof panels, doors and interior
truss work. Your new model will be
right at home alongside the Machine
Shop (933-2902), Modern Coaling
Tower (933-2903), Sanding Tower
(933-3182), Steel Water Tank (933-
3043), and Cinder Conveyor and Ash
Pit (933-3181) as well.
In many bigger cities, the terminal was
part of the railroad’s shop complex,
which can be modeled with the
Backshop (933-3039) and Car Shop
(933-3040).
For more ideas to detail your scene, ask
your dealer, visit walthers.com or see
the latest Walthers HO Scale Model
Railroad Reference Book.
For additional prototype history and
information on turntables, see “The
Locomotive Merry-Go-Round” by
James Alexander Jr. in the July 1995
issue of Trains magazine. Your local
library may also have copies of older
Railroad Maintenance Cyclopedias,
which provided basic information on
turntables and other facilities.
©2004 Wm. K. Walthers, Inc.
Milwaukee WI, 53218
933-2829 I sheet 12/2/04 10:22AM Page 1

INSTALLATION ON YOUR
LAYOUT
Your new turntable has been care-
fully assembled and tested to pro-
vide years of enjoyable operation.
Please take a few minutes to look
over the parts, read these instruc tions
and study the drawings before
starting.
Your new turntable drive should be
powered from its own power pack,
sold separately. Check the output
of the transformer with a voltmeter
before making any electrical con-
nections. The drive operates best at
15 Volts AC or DC, 500mA; a
minimum of 12 Volts is required,
but total output must not exceed 19
Vo lts AC (RMS) or DC.
INSTALLING THE PIT
Your new turntable automatically
reverses track polarity when
turned. As a result, the unit has two
electrically insulated areas where
the track on the bridge is not pow-
ered. These are identified on the
underside of the lip by the “NO
TRACK” lettering (also shown on
the mounting template). Working
approach and fan tracks must be
installed away from these areas –
we suggest placing them at 90° to
the approach tracks. You can, how-
ever, add an unpowered display
track at these points if desired.
The opening in the wall of the pit
houses the optical sensor used as
the “zero point.”
For the indexing to work properly,
this area, along with the small gear
teeth and ring rail molded in the
bottom of the pit, must be clean
and open at all times. If you plan
to paint or weather the pit further,
mask off these areas before start-
ing.
Before installing the pit, cover
the center pivot hole with tape to
keep out dust and debris.
For best results your new turntable
must be installed on a flat, level
surface. Determine the location for
your pit; use the enclosed template
to cut the mounting hole in your
benchwork. Allow at least 2-1/4"
(5.7cm) of clearance below the pit.
The zero reader is mounted direct-
ly below a mounting boss; be sure
to provide clearance in your bench-
work for the reader too.
If your pit will be mounted on a
wooden surface, drill out the areas
for the mounting bosses as shown
on the template with a 5/16"
(8mm) bit. Secure the pit in place
using the eight screws and washers
— if the thickness of your wood
surface is less than 1/2", use addi-
tional washers (not included) for
correct spacing — do not over
tighten as this could cause the pit
to warp.
If you are using foam for the sur-
face of your layout, open the areas
for the mounting bosses slightly
and push the pit into place.
Make sure the pit is level, secure
and properly supported before
proceeding.
POS: Red LED comes on
when the turntable is in a
programmed position.
POWER: Red LED stays
lit when power is on.
RIGHT/LEFT ARROW: Use to move
and stop the bridge.
ZERO: Use to locate the zero point.
SET: Use to program
the stopping points.
INSTALLING THE CONTROL
BOX
This unit is used to program and
operate your turntable. As noted
above, we suggest a dedicated
power pack be used as a power
supply. Do not attempt to run the
turntable at this time.
The control box can be used as-is,
or flush-mounted on the surface or
side of your layout. Simply remove
the four screws from the back to
remove the front panel. Cut a
mounting hole with the template,
place the front panel in the opening
and reattach the back.
Wiring
Connection points are marked
on the underside as follows:
B1 and B2 = connect to rail
power supply; powers bridge
rails.
U & V= connect to AC termi-
nals on power pack; powers
drive mechanism.
All wires are secured using the
small screw terminals.
Plug in the large gray cable
from the indexing unit (located
beneath the pit) into the port
on the side of the control box.
933-2829 I sheet 12/2/04 10:23AM Page 2

INSTALLING SERVICE
TRACKS
With the pit in place, you can
install service tracks. The indexing
can be programmed for up to 60
different stopping positions so you
can add tracks almost anywhere
around the pit – but remember,
don’t install working tracks in the
“NO TRACK” areas.
The bridge is equipped with Code
83 rail; if you are using another
size for your service tracks, use
Walthers Transition Tracks #948-
897 for Code 100 or #948-898 for
Code 70 (each sold separately).
For a smooth transition between
the bridge and service tracks,
you’ll need to modify your rails
by filing the inside ball of the rail
at a slight angle for about 3/16"
(4mm) (see below).
All service tracks must align with
the bridge rails in a straight line.
The bridge can be used as a guide,
but VACUUM THE PIT AND
THE SURROUNDING AREA
BEFORE PUTTING THE
BRIDGE IN THE CENTER
PIVOT! Follow the instructions
below for installing the bridge.
For the rails to sit correctly on the
lip of the pit, you must remove a
few ties from the end of the track.
Important Note: Rails must end at
the edge of the pit — leave a gap
of about 1/16" (1.5mm) between
the end of each service track and
the bridge. Temporarily tape or pin
the service tracks in place so you
can make any adjustments after
programming your stopping posi-
tions.
Wire the service tracks (parts not
included) for power as desired.
PROGRAMMING YOUR
TURNTABLE
Initializing the Turntable
Begin by plugging in the power
pack. With the power pack turned
off, press the SET and ZERO but-
tons down at the same time. Now,
turn on the power and hold both
buttons for four to five seconds.
When the POWER light stays on,
the unit is ready to use. Press the
ZERO button until the POWER
light flashes, then release. The
turntable will move to the zero
point.
Programming New Stopping
Positions
1) Move the bridge from the zero
point to the first track you’d like
to program by pressing and releas-
ing either ARROW button.
Two stop positions are pro-
grammed into the unit for testing
at the factory. Don’t remove these
until you have programmed two or
three of your own tracks! You can
also use these to test the operation
of your unit at this time – simply
press and release either the LEFT
or RIGHT ARROW keys. The
bridge will move in the direction
selected until it locates a factory
setting. The table will over-run the
stop position slightly when turning
counterclockwise — this is normal
— then back slowly into position.
2) Move the bridge to your first
desired position and stop the table
about 1/8" (3mm) from the right
hand rail. (If you go too far, press
and release the LEFT ARROW but-
ton; touch and release either
ARROW button to stop, then move
the bridge counterclockwise with
the RIGHT ARROW button.)
3) Hold the SET button and gradu-
ally inch the bridge rails into a 90°
alignment by pushing and releas-
ing the RIGHT ARROW key as
needed to move the bridge coun-
terclockwise — use the outside
edges of the rails as a guide to
check that all rails are perfectly
aligned.
(If the POS light comes on before
the track is aligned correctly, clear
the setting by pressing and holding
the SET key until the POS light
goes off.)
4) When the tracks and bridge are
aligned to your satisfaction, press
and hold the SET button until the
POS light comes on to show the
stop position is programmed into
the memory.
Repeat steps one through five for
each stopping position.
Important Note:Although tracks
may be directly across from each
other, you must program a sepa-
rate stopping position on each end
of the bridge.
BRIDGE INSTALLATION
Important Note: Before starting,
make sure the bridge rails are
equally spaced about 1/16"
(1.5mm) beyond each end.
Before installing the bridge, thor-
oughly vacuum the entire pit to
remove all debris from the center
pivot point, the ring rail and gear
track. Remove the tape you placed
on the center pivot hole. Insert the
center pivot on the bridge into this
opening. The arch snaps in place
as shown at the middle of the
bridge — don’t glue it down, leave
it removable for track cleaning and
maintenance.
remove with a file
933-2829 I sheet 12/2/04 10:23AM Page 3

TROUBLESHOOTING
POS LIGHT ON CONTROL
BOX FLASHES RAPIDLY; You
may be trying to program a new
position too close to an existing
one; it will also flash if you
attempt to program more than 60
positions.
TO FIND THE ZERO POINT;
Press the ZERO button until the
POWER light flashes – then
release. The bridge will turn
clockwise until it locates the zero
point. NOTE: turn off any other
infra-red sources in the room
when searching for the zero point.
TO REMOVE SETTINGS; Move
the bridge to the desired position
and stop — the POS indicator will
come on. Press and hold the SET
button for a few seconds until the
POS light goes out. (After you
have programmed two or three
new positions, clear the factory
test settings the same way.) To
clear all programmed settings and
reset the factory test positions;
turn the power pack off. Hold
down the SET and ZERO and turn
the power pack back on.
IF BRIDGE IS SLIGHTLY OUT
OF ALIGNMENT WITH
TRACKS (usually all in one direc-
tion); Re-zero the turntable by
holding down the ZERO button
until the POWER light flashes; the
turntable will then re-zero itself
and restore your programmed
stopping positions.
FINAL ASSEMBLY
Once you’re satisfied with the
operation of the bridge and how it
aligns with each track, fasten each
rail securely so its base rests
directly on the outside lip of the
turntable pit. You may wish to
glue each rail to the pit surface, or
spike the track in place at the first
tie on the benchwork. Important
Note: Before doing any scenery
work, such as painting or adding
ballast and ground cover, remove
the bridge from the pit and tape
over the center pivot. Before put-
ting the bridge back in the center
pivot, carefully and completely
vacuum the pit and the surround-
ing area. After reinstalling the
bridge, you must find the zero
point before resuming operation.
Just press the ZERO button until
the POWER light flashes, then
release.
NORMAL OPERATION
Turn on the power pack; the unit is
ready to use when the red POWER
light stays on. Use either ARROW
button to turn the bridge: press and
hold the button to pass stopping
positions. As the bridge approach-
es the desired service track,
release the ARROW key. The
bridge will overrun the stop posi-
tion slightly, then align itself.
When the unit stops, the POS indi-
cator will light; move your loco
using your standard throttle. From
time to time,
“ zero” the turntable
to maintain your programmed
positions.
MAINTENANCE
As operation can be affected by
dust, you may wish to cover your
model with a plastic sheet between
operating sessions.
Zero Point: Make sure this area
and the pit edge is always clean
and free of dust.
Use contact cleaner to clean the
wipers and slip rings on the bot-
tom of the bridge, should they get
dirty.
Counting Wheel: If your table
begins stopping out of alignment,
the counting wheel may have
become plugged with dust. Simply
remove the bridge from the pit and
blow any dust clear of the cog-
wheel. Important Note: Any time
the bridge is removed from the pit,
you must find the zero point
before resuming operation. Just
press the ZERO button until the
POWER light flashes, then
release. The bridge will turn
clockwise until it locates the zero
point and stop. You’re now ready
to resume operation using the
ARROW buttons to move the bridge.
Lubrication: In normal use,
the drive mechanism should
only require servicing about
once a year. Use plastic com-
patible lubricants made espe-
cially for hobby products —
NEVER use household oils or
lubricants! Remove the arch.
Loosen the circuit board,
which is held in place with
double-sided tape. Remove
the three screws from the cover.
Apply a drop of light oil for elec-
tric motors to the bearing. Apply
light gear lubricant to the gear
train. Apply powdered graphite to
the final drive. Reverse these steps
to reassemble — make sure the
motor leads are positioned as
shown.
933-2829 I sheet 12/2/04 10:23AM Page 4