The toy train operator using high-rail, tubular track can make invisible electrical track connections by inserting the blades of male quick-disconnect terminals between the sides of a track rail. These connections are secure, electrically efficient, and can be made at low cost.

In electrical parlance, a "terminal" is anything that goes on the end of a wire. The male quick-disconnect terminal used for track connections is one of a pair of terminals intended as a connector for a single wire. Only the male terminal of the pair is used for track connections.

A male quick-disconnect terminal has two parts: a barrel and a blade. The barrel holds a wire. The blade is inserted into the track rail.

There are two sizes and numerous forms of terminals commonly available. The 1/4 inch blade size is best for connecting to high-rail tubular track. A straight barrel form will be illustrated, but right- angle barrels and other forms of terminals are available.

Quick disconnect terminals are available in "insulated" and "non- insulated" forms and with barrels for different wire-size ranges. The non-insulated form is more convenient for connections to track: the barrel is smaller and it is more easily crimped and soldered.

Terminals are usually made of brass or copper with a plating. Tin plated terminals are easy to solder. Tin plating appears a dull, matte gray. Other plating materials appear like shiny chrome and may not be capable of being soldered.

Terminals are available from a number of manufacturers and are carried by most electrical and electronics distributors. See Sources for Toy Train Layout Supplies for suggested suppliers and part numbers.

A wire is attached to the terminal barrel by crimping, soldering, or both.

A terminal's barrel should be selected for the size of wire being used: for power (center-rail) and power-common (non-insulated outside rail) connections, #18, #16, or #14 gauge wire is best. #22 gauge wire serves for connections to insulated rails for trackside accessories or Three-Rail Innovations' "Universal Trackside Accessory Controller."

Wire can have a solid or stranded copper core. Stranded wire is easier to route. The copper wire can also be tin plated, making it easier to solder. The term "hook-up wire" applies to the most appropriate wire type for wiring train layouts. #14 stranded wire for building construction is economical and suitable for larger wire gauges. #10 or #8 bare, solid core, wire is good for "track common" distribution: #16 gauge wires to outside rails can be soldered to the distribution wire at any point without the need for stripping insulation.

Terminals are best attached to a wire by crimping the terminal's barrel around the wire. Crimping is accomplished with a specialized tool.

For toy train operators, a multipurpose hand tool that has crimping dies for non-insulated wire terminals is a good choice.

Hand tools with dies for non-insulated terminals are commonly available from hardware stores and electronics supply houses. Make sure is has dies for non-insulated terminals.

Crimpers for non-insulated terminals will have a set of die-pairs that look like this:

The semicircular part of the crimp die is referred to as the cavity; the pointed part is the punch.

Each die-pair is marked with the wire sizes of the terminal barrel appropriate for the cavity. Choose a die-pair marked for the terminal barrel size being used. Generally, the barrel of the terminal will closely fit within the die cavity.

Attach a wire to the male quick disconnect terminal with the following steps:

1. Strip the Insulation Off an End of the Wire
   
   Strip a length of insulation from one end of the wire a little longer than the length of the terminal barrel.
   
   
2. Hold the Terminal in the Crimper
   
   Place the barrel of the selected terminal into the die cavity and close the handles of the crimper just enough to hold the terminal in place.
   
   Orient the terminal as shown, with the blade-end up and the punch against blade side of the barrel. The punch should be centered length-wise on the barrel.
   
   
3. Insert the Wire in the Terminal
   
   Insert the bare end of the wire into the terminal barrel (underneath in the diagram).
   
   The end of the wire should just emerge from the blade end of the barrel (mostly to make sure the wire is fully inserted).
   
   Hold the wire in place for the next step.
   
   
4. Crimp the Wire in the Terminal
   
   Close the handles of the crimper to drive the punch into the barrel and against the wire. Squeeze tightly.
   Release the handles and remove the terminal and wire.
   
   
5. Check the Finished Crimp
   
   Hold the terminal between thumb and finger of one hand and tug on the wire.
   
   The wire should hold.
   

If the wire pulls out of the terminal barrel easily, then discard the terminal, trim the wire, start over again, and adjust the procedure by:

• Squeezing the handles more tightly when performing the crimp.
• Choosing a terminal with a smaller wire gauge barrel.
• Choosing a smaller die cavity.
  or
• Stripping the wire twice the length of the barrel and folding the wire in half before inserting it into the terminal barrel.

Practice a bit until your crimps reliably hold the wire.

If you are confident with crimping, the wired terminal is ready for installing it into the track rail. If not, a bit of solder to wire and terminal barrel will make a reliable connection.

Electrical connections to tubular track are made by installing a male quick-disconnect terminal, with the wire attached, between the rail sides from underneath the rail. The blade of a small screwdriver is used to open the rail sides. The terminal blade is installed, and the screwdriver removed. The terminal is securely held.

1. Use a small screwdriver blade to open the track rail.
   
   A screwdriver with a blade 1/8 inch wide or smaller is pressed between the rail sides from the underside of the rail to open a gap for the terminal.
   
   Chamfering the end of screwdriver blade will make this easier.
   

   

2. Open the rail a little wider than the terminal blade.

   The rail sides should be opened a little wider than the thickness of the terminal blade; sufficiently wide so the terminal blade can be easily installed.

   The rail sides should not be opened so far as to distort the rail and prevent it from gripping the terminal blade when the screwdriver is removed.
   

   

3. Insert the terminal blade between the rail sides.

   The terminal blade can be started between the rail sides, next to the screwdriver blade holding the rail sides open, holding it with finger and thumb.

   Seat the terminal with pliers; it should go in and touch the top of the rail.
   
   

4. Remove the screwdriver blade.

   Give the terminal a tug to make sure it is secure. It can rotate back and forth a little, but should not pull out easily. If it seems too loose, the rail sides can be tightened with track pliers.
   

Invisible track connections are used on a train layout by locating the track on the layout surface, marking the track rails to receive the terminal and marking the table surface for a hole to receive the wires.

Install wired terminals at the marked track rail locations, drill holes in the table to receive a terminal barrel and wire, place the wires in the holes, and lay the track.

Details of this process will vary, but the following will assist:

• When marking for the holes on the table, note that the terminal barrels are a little offset from the rail center line. Deciding on a convention of which side of the center line the barrel is oriented will make locating the table holes easier.
• Make sure the track is accurately positioned before marking the holes in the table; track will be constrained by the terminal barrel and wire in the hole in the table and, therefore, cannot be moved much.
• Leave some extra wire near the hole, under the table, in case the track needs to be lifted from the table for some reason.
• There is usually a bit of flexibility in locating connections along the track. Table supports and other obstacles can be, thus, avoided.
• Surface wiring can be accommodated by bending the terminal or using right angle terminals to allow the wire to exit under the track.

A toy train layout using quick-disconnect terminals for power and insulated rail electrical connections will look better and will operate more reliably than one with track lock-ons and fahnstock clips.