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Model railway points - All you need to know in one place

If you're looking to create a model railway, you'll need to know how to use points (also known as turnouts).

In this article, we'll show you

  1. how do model railway points work
  2. how to wire model railway points
  3. how to clean model railway points
  4. how to electrify (motorise) model railway points
  5. how to ballast model railway points

how do model railway points work

Model railway points are used to change the direction of train travel. They're typically made from metal and plastic and can be operated manually or by a point motor.

The most important thing to remember when using points is that they must be correctly aligned with the track. If they're not, your train could derail or collide with another train.

The photo below shows the important parts of a model railway point

The point blades are hinged halfway along their length and at the toe end of the point, they pivot on the tie bar. It is by moving the tie bar that the direction of the point is set.

PECO points have a v-shaped spring that positively holds the point blades in position.

Points can be operated either manually, electrically, or mechanically.

For a manual system, you would simply move the point blades by hand.

To move a model railway point electrically, you need to use a point motor.

You may also use the 'wire in a tube' method

Key Tip
Cut a hole in the baseboard below the position of the tie bar before laying your point! this will save a lot of hassle later when you want to fit a point motor.

how to wire model railway points

When you are wiring a crossover you need isolating joiners between the points. This stops electrical short circuits that would prevent your train from running. Most modern controllers have short circuit protection, but if yours doesn't a short can damage engines, track or the controller. 

Insulfrog Points

Insulfrog points are used on model railways to change the direction that a train is travelling and at the same time isolate the track not selected by the point. Insulfrog points get their name because the frog does not conduct electricity.

Pros and cons

The advantage of insulfrog points is that the wiring is a lot simpler, the point blades are used to power the output track. The disadvantage is that small wheelbase locos at slow speeds may stall on the frog.

Power is simply fed from the TOE of the point, no other connections are needed.

Power can be supplied through a dedicated power connection or through the metal rail joiners to a live piece of track.

The next two images show which parts of the insulfrog point are electrically connected depending on which way the point blades are switched.

Normal point direction, that is straight through.

Reversed point - that is taking the branch

Electrofrog Points

Insufrog points are also used on model railways to change the direction that a train is travelling but this time because the frog does conduct electricity the wiring is much more complicated.

Pros and cons

The advantage of electrofrog points is that small wheelbase locos at slow speeds still receive power as they cross the frog. The disadvantage is that you have to switch the polarity of the frog yourself.

Power is fed from the TOE of the point, you will also need to take the power feed for the frog from there too.

Power can be supplied through a dedicated power connection or through the metal rail joiners to a live piece of track.

The next two images show which parts of the electrofrog point are electrically connected.

Normal point direction, that is straight through.

Reversed point - that is taking the branch

OK, so how do you switch the frog polarity?

In general terms, you use a switch connected to the tie bar of the point, this switch is a 2-way single pole switch that connects either a positive track or negative track to the frog feed.

the actual precise details of how to do this with electrically operated points are covered in the section 'how to electrify model railway points'

For manual points, a microswitch operated by the tie bar will suffice.

how to clean model railway points

If your model railway points are dirty or covered in grime, you may need to clean them in order to ensure smooth and reliable operation

There are several different approaches that you can take when it comes to cleaning your model railway points.

Track Rubber

Great for a plain track but not so good for points that tend to collect the rubber debris created as you rub the track with the cleaner.

Methylated Spirits and a lint-free cloth

This is how I used to do it 20 years ago but it doesn't do anything for the sides of the point blades, and on insulfrog points, you rely on that contact area for smooth running.

Track Magic and Hand portable vacuum

We have found track magic (other track cleaning liquids are available) to be excellent for cleaning tracks, locomotive wheels, pickups, and motors. Their complete pack includes a bottle of cleaner, a sponge pad, and a micro brush.

Firstly vacuum the loose dirt, dust and debris out of the point, when you have done this, the micro brush soaked in Track Magic makes easy work of cleaning the point blades and rail stocks they contact against.

how to electrify model railway points

There are three types of point motors that can be used on a model railway, solenoid, servo, and stall motors.

solenoid point motors

solenoid point motors are the simplest type of point motors and consist of a coil of wire that is activated by an electric current, this creates a magnetic field that pulls the armature plate towards one side or the other.

If you choose the PECO solenoid point motors we have found them very reliable, although they do work best with a capacitor discharge unit.

3 key components are required for the PECO solution mounted under the baseboard, the mounting plate, extended point motor, and change over switch.

The base plate is screwed under the baseboard with the extended driver pin located through the tie bar. Take care to ensure the solenoid position (left or right) matches the tie bar position.

When wiring for frog polarity, the single contact on the switch goes to the point frog, the other two contacts are for the - and + control voltages.

The instructions for connections are for the switch as viewed below.

The left-most contact should be connected to the left-hand rail at the Toe end. The contact next to it should be connected to the right-hand rail at the Toe end.

Servo point motors

Servo point motors are a more sophisticated type of point motor that uses a servo mechanism to move the armature plate. Special electronics are required to drive the solenoid and are usually DCC controlled. The advantage of a servo motor is its slow action, the disadvantage is no built-in switches for frog polarity.

There are several competing systems on the market, we are very happy with our dijikeys system and you can program it to trigger a relay to change frog polarity when the servo changes the points.

Having tried the PECO smart switch system we do not recommend using it for electrofrog points as we never got the additional polarity changing modules to work.

Stall point motors

Stall point motors used a geared drive to move an actuator pin in a straight line, much the same as a solenoid motor. This puts less strain on the connection to the tie bar.

The advantage of using this kind of point motor is that it is easier to set up and operates with slow action, and is typically more reliable and less prone to failure than other types.

Many of them have one or more switches built in to switch frog polarity and operate signals.

how to ballast model railway points

Adding ballast to points helps complete 'the look' but it has to be done carefully and only just enough to give the appearance of ballast.

Apply it in small amounts dry, and use a paintbrush to spread it out, avoid getting any ballast near the tie bar.

Just enough to cover the baseboard between the sleepers and below rail height. Do not get any between the guard rails

Be especially careful not to obstruct the point blades

Keep the tie bar completely free of ballast

Before you fix the ballast down, run 4 or 5 trains through the points in all directions to make sure there are no obstructions.

I used a 50/50 mix of PVA and water with 2 drops of washing up liquid (which breaks the surface tension and allows the solution to soak into the ballast) applied with a dropper to the ballast between each sleeper.

do not allow the glue onto the tops of the sleepers or you could glue the point blades so they do not move.

Other resources

How to start a model railway

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