REMOVABLE BUILDING A Λ SIGNAL

Presented by BOB VAN CLEEFof the North River Railway

A BASIC DESIGN

• Almost any layout can use signals.

• This presentation shows how to build a simple 2-aspect signal.

• Mass production techniques make construction fast, easy and reasonably good looking.

SIGNAL HEAD SHIELD

• We will start by making the shield• It can be fabricated from any thin

material including .020 brass shim stock.• I used unclad glass epoxy printed circuit

board.• These heads were about ½” (HO 3’-6”)

wide by 7/16” (HO 6’-9”) high.• Railroads used a greatly varied sizes.

• A simple tool can be made from scrap materials to shape multiple the shields to a uniform size easily and quickly.

• Drill 1/8 holes (.125) for 3mm LEDs.

• Glue or solder a bit of 1/8” OD tubing in top hole to hold shield in place while sanding or filing to size.

TOOL FOR MAKING SHIELDS

SHIELDS BEFORE AND AFTER

• Simply cut shields to rough size then use this to sand or file shields to shape.

MAKING THE FINALE

• The Finale at the top of the mast is made by soldering a short length of telescopic tubing inside the mast.

• Overfill the center then file to shape.

• The mast can be placed in a hand drill and filed if a lath is not available.

• This technique can also be used to make flagpoles and other decorative details.

Close-up of Finished Finale

• This is what the finale looks like before painting.

• Note that the (2) sizes of tubing are plainly visible.

• Be careful not to dull the tip as solder is very soft and easily dented.

About the LEDs

• LEDs are used for the signal lights.• LEDs vary in color and size.• Note that the long lead (side opposite

flat on rim) is the anode (+). • Different Colors will draw slightly

different currents due to their chemical makeup.

• Slightly different resistance values might therefore be required for even brightness.

LEDs Used for signal lights

NOTE: make sure to observe the polarity or else the LED will not work as expected.

• T-1 (3mm) LEDs were used for this project.

• This size will fit a .125” hole• Cut and bend leads as shown.• First bend the anode (+) lead.

This is the longer lead opposite the flat on the outer rim.

• Then bend and cut the cathode (-) lead.

A SIMPLE SOLDERING FIXTURE• A simple fixture is used to hold

parts in place as the signal is assembled.

• Standard height signals will use the (2) upper holes for an offset signal head.

• Dwarf signals will use the (2) lower holes for shields centered with the mast.

• This technique can be used to build a multitude of signal configurations.

HOLDING PARTS IN PLACE

• Note the (3) pins that will hold the mast in the proper position.

• The aluminum clamp swivels to hold parts in place.

• Make sure to include clearance for the shield.

SOLDERING the LEDs

• The next step is to file the groove in the mast.

• Re-install the shield with the LEDs in place.

• Solder the anode lead of the LEDs to the mast.

• CAUTION – use as little heat as possible. Consider using a low melting point solder.

COMPLETING SIGNAL HEAD

• This drawing represents the completed signal head.

• Notice the notches for the LEDs at the top and for mounting to the base at the bottom.

“WIRING” the signal head

• Phonograph pickup wire (7 x #36) makes a nice “cable” for signal lights.

• Again, use as little heat as possible when attaching to Cathode (-) lead of the LED.

• Bend and thread the wire through the mast to the base.

REMOVEABLE SIGNALS

• Signals near tracks can cause problems.

• Signals can easily be damaged during track cleaning.

• It is also hard to clean tracks near signals.

• Making signals removable remedies these problems.

DETAIL OF SIGNAL BASE

• Here is how headers can be used to make signals removable.

• A male connector can be seen in the base of the signal.

• A female connector is buried in scenery can bee seen in the lower left.

HEADERS

Male and Female Headers cut to shorter lengths for use in signals.

• Headers , a type of electronic connector, can be purchased in various lengths.

• Most are scored for easy cutting to shorter lengths.

• The male (upper) half will be soldered to the base of the signal mast.

• The female half (lower) will be embedded in the scenery / table top with wires extending below table level.

ASSEMBLING BASE

• This schematic shows the connection between the mast and the header.

• Note that the mast is soldered directly to (2) pins of the header.

• The (2)wires from the LEDs exit the base of the mast through a short notch and are each soldered to one of the remaining pins of the header.

NOTCHING THE MAST BASE

The exact dimensions of the notch is not critical. Either putty or a signal box will

hide the actual connections.

The SIGNAL BOXThis can be made from a simple block of wood. Drill a hole through the center from the top, then hollow out the base from the bottom.

Signal box on mast.

VIEWS OF FINISHED BASE

Wires soldered to pins on header.

Mast soldered to header.

FORMING PLATFORM RAILS

• A simple forming tool is used to form both the signal railings and the platform base.

• (5) pins and the edge of a block are used to bend #22 brass wire for best results.

• Copper wire that has been stripped of all insulation can also be used.

WIRE IN FIXTURE BEING FORMED

• This shows a handrail being formed.

• Note the extended wire at the top is bent sharply down at a right angle over the top of the forming tool.

FORMED SHAPES

• Here are the handrails and platform base.

• The finished platform is at the bottom.

• Dozens of railings can be made in just a few minutes.

FORMING THE PLATFORM

• The “floor” of the platform is constructed using several parallel wires.

• These wires are held properly spaced with a fixture.

• Solder the platform base in place and trim wires.

FINISHING THE PLATFORM

• Note that the shorter fixture is made by drilling through the longer piece and insures that the wires are held exactly parallel.

• Use regular (higher temp) solder for the platform.

PLATFORM ASSEMBLY

• The handrails, platform and ladder can now be soldered in place.

• Use a low-temp solder to avoid problems with solder on platform melting while doing this work.

• File and clean all joints.

TWO SLIGHTLY DIFFERENT VIEWS

TWO MORE VIEWS OF SIGNAL HEAD

Side VIEW OF SIGNAL

A DWARF SIGNAL

• A dwarf signal is a bit different.

• There is no platform or ladder, or finale.

• Also, the head sits on top of the “mast”.

• The signal box is built up from wood-filler and sanded square.

SIDE VIEW OF DWARF

• The LED connections are the same as on a standard signal.

FINISHED SIGNALS

For More Information…

Digikey http://www.digikey.com/

Source for wide variety of electronic related parts and hardware including LEDs, Wire, Solder, Copper wire, printed circuit board and headers.

Walters http://www.walthers.com/

Largest single supplier of model railroad supplies including stripwood, brass telescopic tubing, ladder stock, brass wire and paint.

Also, see clinic on STALL MOTOR CONTROL for more information on LEDs.

This presentation has been brought to you by the North River Railway

Bob Van Cleef46 BroadwayCoventry, CT 06238http://www.northriverrailway.net

THE END