LGB Forney Modeling Tips
The Forney from LGB is an attractive small engine.
My wife wanted one, and a South Park loco with sound and smoke was her anniversary
present in 1999. We have repainted and lettered it for the Lake Town & Shire,
changed the Kadee couplers, and installed a Digitrax decoder. Before we installed
the decoder, we ran the Forney as number 00 on our DCC layout. It ran well and
the sound worked well, but we had to manually reverse direction every time it
went through the current switching circuitry on the reverse loops. So we decided
to try to convert to DCC while keeping the original LGB sound. This turned out
to be a pretty simple conversion.
- Whether you want to install a decoder, install
a sound system, or just repaint the engine, you will want to disassemble it.
Here's how.Remove the handrails. They pull out of the boiler, then you have
to turn them to get the bend out of the cab. I had to use a pair of needle
nose pliers to get some leverage to pull them out of the boiler.
- Remove the three boiler pipes.
- Remove the two brass rods to the pilot. Pull
them out of the boiler first.
- Remove the pilot. A single screw in the bottom
holds it in place.
- Remove the ash pan on the bottom by taking out
one screw in the center.
- Remove six screws from the bottom of the cab
area. These hold the cab and the water tank/fuel bin in place.
- Remove the water tank/fuel bin. It has two tabs
that fit into the back of the cab. You will have to lift up the back of the
cab to get these tabs out. Pull the plug from the the sound board and remove
the three screws and washers holding the speaker to free the water tank/fuel
bin completely from the frame.
- Remove two small screws in the side of boiler
by smoke box.
- Remove the smoke box by pulling it forward.
Be careful not to pull the wires loose for the headlight and the smoke unit.
You will need to keep the smoke box near the boiler tethered by these wires
while you complete the next several steps There is a small black spacer at
the front top of the boiler. Remove this and set it aside as you remove the
- Remove the two screws in the boiler side below
- The cab and boiler are removed as a unit. Slide
this unit forward and tip it up to get it past the engineer. Be careful not
to break the wires going to the lights in the cab.
- Remove two screws that hold the backhead in
place and remove it. It takes some wiggling to get it past the engineer. Notice
that the wiring tunnel on the floor that includes a simulated coal spill will
also come loose at this point.
- Make a diagram of the wires connected to the
circuit board between the two weights or use the photograph below. Unhook
the wires for the headlight, smoke unit, and cab lights from the circuit board.
This will let you completely remove the smoke box, boiler, and cab from the
In the photo, the front of the engine is to the
right. There are four pins on the left next to the copper coil. The top two
(black on left, red on right) go to power pick-ups in the trailing truck and
the bottom two (brown on left and yellow on right) carry power to a plug in
the rear bumper. These four pins are left disconnected in the decoder installation
I will describe below. There are two plugs and three wires at the right edge
of the circuit board that connect to the motor block. The top plug appears to
connect to the chuff switch and also to a wire that signals the sound unit to
ring the bell twice when the engine starts up. The bottom plug has four wires
(two have been cut in the photo.) The green wire goes to the right motor pin,
the yellow goes to the left motor pin, the brown goes to the right power pick-up,
and the white goes to the left power pickup. The three wires appear to connect
to reed switches in the motor block that ring the bell and toot the whistle
when the train passes over magnets on either side of the track. To the left
of these three pins are two pins that connect to the headlight in the smoke
box. A pair of thin black wires connect to these pins. Next to the left are
pins for two wires, white on top and black on the bottom, that connect to the
smoke generator in the smoke box. Finally, there are three pins for white (top),
red (middle), and black (bottom) wires that connect tot the inside and rear
lights in the cab.
- Remove three screws from the circuit board and remove the
- Remove four screws from the front (larger) weight and remove
- Remove two screws and plastic washers under the large weight
to remove the motor block.
- Remove two screws at the ends of the bottom of the motor
block and two screws in the top of the motor block. The top and ends of the
motor block will now come off.
This is as much disassembly as is needed to install the decoder.
Here are a few further tips if you plan to repaint the locomotive.
- My engine came as a wood-burner, but I wanted to convert
to coal. Remove two small screws from the sound board in the water tank/fuel
bin to get the sound board out of the way. Then remove the water filler cover
and one screw in the bottom of the plastic wood load. Once the plastic wood
load is out of the way, the water tank/fuel bin is configured for coal. I
added some small bits of real coal to the front fuel bin area. (It's interesting
that this engine came with a plastic wood load AND a coal spill in front of
the fuel bin!)
- Pull the headlight straight up to remove it from the smoke
box. Pull the lamp from the socket. Put a bit of plastic over the socket.
The top of the smoke stack has a tab on the front edge. Use this to pry off
the top of the smoke box. A ring holds the cinder screen in place. Remove
it and the screen. The smoke box and the top of the smoke stack are ready
- Remove the screw holding the boiler to the cap and separate
these two pieces. Remove the screw holding the sand
dome to the boiler. Remove the sand pipes and replace the sand dome. The boiler
unit is ready to paint.
- Remove the front windows from the cab. You will have to press
the cab sides out and the windows in to get the raised frames on the windows
out of the holes in the cab, but with a little work it can be done.
Remove the door/window units from the rear corners of the cab.
Again, this will take a bit of pressing and wiggling. Pull the rear light
and bulb off the top of the cab. I suggest you also pull the bulb from the
inside roof of the cab to avoid getting any over spray on it. The cab is ready
- The headlight and the rear light have a notch at the bottom
of the lens. Use this to pry out the lens, then remove the reflector. I stuffed
the light compartment with paper towel before spraying the lights.
- Pull the hinge pins out
of the window/door units making sure not to lose the wire spring. This make
it easier to paint the door and the window trim.
I didn't remove the cylinders before painting them, but it would
probably have made painting much easier.
Installing the Digitrax DG380L Decoder
This is super easy. When you are finished, the motor will be
under control of the decoder but the sound system will work exactly as it did
before. Instructions for disassembling the locomotive are given in the
Cut the green and yellow
wires from the plug shown in the photo of the motor block. The motor is now out
of the circuit.
- The brown and white
wires still attached to the plug go to the power pick-ups. Cut these
about half way between the motor block and the plug. Strip the ends
and solder them back together, but include a piece of red wire about
ten inches long with the white (left) power lead and a piece of black
wire about ten inches long with the brown (right) power lead. Insulate
the splices with shrink tubing. The diagram below illustrates these
- After testing the decoder
to make sure all the functions were working, I cut the red, black, orange,
and gray leads on the decoder to a length of about 4 inches. Since I wasn't
going to use the extra functions on the decoder, I pulled the unpluggable
wiring harness out of the decoder leaving only the thicker red, black, orange,
grey, and blue leads.
- Two red and black power leads
from the rear truck come up through the speaker grill. Cut these off about
four inches from the speaker grill. Join the red wire from the rear truck,
the red wire from the motor block, and the red wire from the decoder in a
three-way splice. Join the corresponding three black wires in the same manner.
- Cut the yellow and brown wires
going to the plug at the rear of the locomotive. Cut them close to the plug.
Splice the yellow wire to the orange lead on the DG380L and splice the brown
wire to the grey lead on the DG380L.
- Reassemble the locomotive.
It's a little tricky fitting the decoder in the water tank/fuel bin. I attached
the decoder to the side of the compartment with some double-sided tape to
make this a little easier. I also wrapped the blue decoder lead around the
other wires to hold them together in a rough tether. I coiled this and tucked
it up into the water tank/fuel bin as I lowered it into place.
a Rear Truck Derailment Problem
The Forney is front-heavy. When it goes through
a left curve, for example, the weight shifts to the left front of the engine.
This raises the right rear at the same time the left rear of the body presses
down on that side of the truck. This will cause the right rear-most wheel to
rise above the rail. And since the train is rounding a left curve, the right
rear-most wheel tends to ride over the track.
The rear truck is mounted a bit too close to the
body of the engine. I removed the truck and put a flat steel washer under it.
I don't know the size, but it was about as thick as a dime. I had to gently
stretch the pickup wires as I lifted the truck off the center pin. After I put
it back together, the Forney ran over all of our mainline, including the extra-wide
Aristocraft switches, at all speeds with no problems. The rear truck still wants
to derail on the frogs of the short Aristocraft switches, but that's a different
problem for which I have not found a solution.
Air Pump, Air Tank
The LGB sound system on the Forney cranks out the
sound of an air pump when the engine comes to a stop. But search as you may,
you won't find that sucker anywhere on the engine. And even though there is
a reservoir for air for the engine brakes, there is no primary air tank on the
engine. So I decided to add an air tank to the right side of the engine and
to mount an air tank to the top of the water tank. I removed the laughable wood
load from the water tank and built up a load of real coal while I was at it.
The air tanks is a commercial kit, but the air pump is built up from styrene
tubing and brass rod following plans from David Fletcher's master class on building
a Baldwin 8-16-D 2-6-0 on myLargescale.com.
I simply can't say enough about what a great resource this is. Thank you, thank
you, thank you, David!
The backhead also invited some attention. I shaved
and sanded off the throttle molded to the backhead and some of the other detail
including all the rivets. I left the molded firebox door, water glass, oil can
shelf, what appears to be part of a hydrostatic lubricator, and a manifold with
two valve handles on top of the backhead. I also removed the odd levers on each
side of the firebox and the gauges mounted sideways on top the boiler. I used
commercial detail parts for the new throttle, Johnson bar, gauges, and try cocks.
(I attached one of the original gauges to the right of the commercial casting
so I would have a boiler pressure gauge, and primary air gauge, and an air gauge
for the locomotive air brake reservoir.) I built the injectors, brake stands,
drain, and hydrostatic lubricators from brass rod, styrene, and a couple of
beads. Again, I relied heavily on David Fletcher's master class on myLargescale.com.
2004 Donald Nute
page last modified: 2/9/2004.
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