SWITCHES- The Learning Curve

It has been nearly 40 years since I installed my last switch machine. So for me, I am at the steepest part of the curve. Well, I was able to take to first step up the curve. I got one to work the way it was intended.
Several months ago, I decided to try out the Blue Point manual switch machine. It is a simple device activated by a chock cable. That term might confuse some since automobiles haven’t had choke cables for over fifty years. Several modelers have been using these machines for a while and liked them.


I found this picture on the web but it shows a typical installation with the choke cable for control.  It should be easy to install the machine if you had an open framework like this module.

My layout uses “L” girder construction.  As it happens the girder is directly under two switches.   So a simple installation turned out to be a royal pain.   Here is a shot of my machine installed between the girder and table top.

BP undertable

The installation was aided by installing the machine a piece of 1/4″ wood which was long enough to allow screws to be inserted more easily.

Now that the machine was in-place, I stumbled though a series of problem related to position of the machine, points and the table slot for the trip wire to function fully.    Along the way, I upped the trip wire size to .047″ steel.   I had to reduce the size of the trip wire diameter to approximately .030″ in diameter.  I drilled a hole to the throw bar to accept the wire.

BP points

A lot of modelers have used the brass throw and gauge bars from Right O’ Way.   I have several sets but noticed that the Irish Tracklayer has a set of bars to tie the points together.  They are cast in an engineering plastic and can take some amount of abuse.  The neat aspect is that you don’t have to glue two parts together with insulating paper.   They also have the right gauge to work with P48.   The points are held in-place with steel pins the go through the bar.


You can buy these items from Irish Tracklayer on Amazon or direct via phone call.    I was looking at the P48 Photo section on my Yahoo group and saw that John Houlihan (owner of Irish Tracklayer) john@irishtracklayer.com





3 thoughts on “SWITCHES- The Learning Curve

  1. Gene,
    Thanks for the tip on the throw bars. I have several upcoming locations they will help with. I’ll use them in the rear of some scenes. John keeps coming up with unique items, but I don’t regularly follow his web site, so your mention was timely.
    You mentioned .031 wire which I assume is music wire, correct? Did you also use the built in switch on the Blue point to change frog polarity?
    I am about to try a servo to throw the points. Since they have no built in switch, I intend to use Frog Juicers to change the polarity automatically.

    • Ben
      It is music wire. I increased the diameter to get less flex. I found that isn’t necessary. The points were hindered by a spike that I had left on one point.
      I am using the Blue Point to route power but will go to Frog Juicer.


  2. Gene,
    I mount my Tortoise machines at the layout edge and normally have a rigid rod from the machine to the throwbar crank. I have two switches for which this would not work and so used the “choke cable” method to reach the throwbar crank. The choke cables are actually model airplane elevator/rudder control cables just like the one in your photo that I found in a hobby shop. They come in various lengths. One thing I learned in their use for this application, is that they must be securely fastened all along their length so that no flexing can occur. Any flex changes the effective length of the movement at the throwbar.

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