Installing Hornby Point Motors

[Gerry Rumney]

My new retirement project is to build my own model railway in the garage and I have built the base board, decided on the layout, and now want to consider installing point motors where necessary.

Can anyone tell me how easy it is to install such motors?

I have a general knowledge of electrical wiring.

Thanks

 

[2e0dtoeric]

This is one of those 'it depends' questions!

It depends on what kind of motors you intend to use! There are three basic types, a solenoid, a 'snail', or a servo controlled (as in radio-controlled model) one.

Then there are two sub-divisions, surface mount, or sub-surface mount.

Surface mount needs room for it to fit in between tracks, or you can use stiff wire 'push-rods' to remotely fit them, then they can be hidden in buildings or under scenery.

Sub-surface goes underneath the base-board, and needs a slot cutting in the board directly under the point, so the 'slide-bar' (I've forgotten the proper name) is directly over the slot. The motor has a pin that extends up through the slot, and drives the slider one way or the other.

Solenoid motors need a CDU (Capacitor Discharge Unit) to give a reliable pulse of power to the solenoid. This type is 'cheap and cheerful', but on the down-side, each time you 'fire' the solenoid, it gives the point a thump, so shortens the useful life. These types need a momentary or 'passing contact' type of switch, or the old stud and probe method of switching.

The snail type need a constant voltage applied, and move from one side to the other more realistically, but can be fiddly to set up.

The r/c servo type are fairly new on the railway modelling scene, and work very much like the snail type, but use a simple interface control unit, which, in most cases, can have the speed of travel, and the end-point limits adjusted to suit.

Then you need to consider the frog polarisation switching. If you use plastic frog points there is nothing more to worry about, as they switch themselves to the selected 'running' rail. Live-frog points need polarity switching to prevent short circuits.

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If you search this and many other forums, you will find loads of how-to info on this subject. A good place to start is the Brian Lambert site, the address you can find on here and other places, or google it. (No doubt someone will nip in and post a direct link!)

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Before you start fitting point motors, though, have a good play with your layout before you start cutting holes, etc, to make sure the trackwork is all working properly, and is the way you want it. It can be a painful (sometimes literally!) process to go all the way through wiring up and fitting, then decide that you don't like that bit because - - and have to undo and lift it all again, leaving holes in the boards.

That also applies to things like ballastng the track!