B&M New Hampshire Branch

Jim Wiggin Jul 12, 2019

  1. Jim Wiggin

    Jim Wiggin Staff Member TrainBoard Supporter

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    Installing Servos for turnout control
    With the CTC box finished, I figured I would show you all how I install the Tam Valley Servo Turnout Controls. In this series of images, I will be using Atlas Code 55 turnouts, but this process will work for any manufacturer. Let's get started.

    BM028.JPG
    The first thing we must do is dry fit the turnout where it will go on the layout. In the example, this is one of the mainline switches. Two holes must be drilled per turn out, one 1/4-inch hole for the servo throw arm mechanism and one 1/8-inch hole for the wire that will power the frog. It is critical to get both of these holes centered for best operation, however this can be difficult. I found the solution by the way of a blank self adhesive address label. Above you can see I have centered the label to the turnout throw bar.

    BM029.JPG
    With the throw bar centered as seen above, I use a T-Pin to produce the needed mark to drill. The Atlas turnouts have a similar tab for the powered frog and I use the same process.

    BM031.JPG
    Here, a 1/8-inch bit in a cordless drill is used to drill a pilot hole for the servo throw bar mechanism. It was also used to drill the hole that will be used for the wire that will power the frog.
     
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  2. Jim Wiggin

    Jim Wiggin Staff Member TrainBoard Supporter

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    BM032.JPG
    Using the 1/8-inch pilot hole as a guide, the 1/4-inch bit is used to carefully open up the hole that will allow the servo to throw the throw bar.

    BM033.JPG
    Here, the 1/8-inch hole is drilled for the powered frog wire.

    BM034.JPG
    Now the wire for the frog can be threaded through. I choose green wire for the frogs, it seamed appropriate.

    BM035.JPG
    I now simply apply a thin layer of yellow carpenters glue to the roadbed and the three areas of track away from the throw bar mechanism, one doesn't want to permanently glue the turnout in one direction. I tend to avoid the 1-inch section from frog area to the base of the throw bar. Now the green frog wire can be fed through the plywood base and into the eyelet and soldered. Be careful with the solder, it doesn't take long for the delicate ties to melt. I also (not seen here) trim the opposite side of the throw bar making sure to cut it carefully and file it smooth.
     
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  3. Jim Wiggin

    Jim Wiggin Staff Member TrainBoard Supporter

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    Previously, I showed the Tam Valley boards that relay the command from the push button controller to the servo mechanism and the way it was powered. Here is a refresher in case you have forgotten:

    BM082.JPG
    Two Euro style terminal strips bring in power from the main bus. Because my layout is small and only has a total of six turnouts, I'm using the main power from the bus line. I highly recommend using a DC power source that is independent of your bus main if you have more than this. On the City Job, I had both a DC power bus line and a DCC bus line. The power going into the boards is just standard + and -.

    BM083.JPG
    In the past, I simply soldered the green, red and black wires onto the micro switch and installed the servo. Then I would solder the the black wire to the black DCC bus and the same with the red. This made things difficult in installation as well as trouble shooting should a problem arise and they did with the City Job. I ordered more of these Euro style terminal strips and cut them down to two sections with four terminals and installed them to the bottom of the module.

    BM084.JPG
    Next I cut three pieces of wire, 1-inch long both black and red as seen here.

    BM085.JPG
    I stripped 1/4-inch of insulation on either end.
     
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  4. Jim Wiggin

    Jim Wiggin Staff Member TrainBoard Supporter

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    BM086.JPG
    The small wires are used as jumpers to power all terminals, in this case the positive. The wires that come from these terminals will connect to the servos micro switch will power the frog.

    BM087.JPG
    For each servo, I installed a three position wire terminal. The GREEN wire above is the wire that was previously soldered onto the Atlas turnout's frog. Both the BLACK and RED wires seen here are connected to the 4-way terminal blocks we saw installed above. You'll also notice the pencil lines near the terminal strip and the 1/4-inch hole. This is the area in which the servo will be installed. I find it easier to hold the servo mechanism in place and test the position to get the proper throw for either direction on the turnout. Once this achieved, I trace the wooden servo mount as seen here, then apply a light coat of yellow carpenters glue to both module bottom as seen here, and the servo mount, staying away from the actuator wire. I allow the glue on both assemblies to dry.

    BM088.JPG
    While the glue is drying, I cut three wires, Green, Red and Black about 3 inches long and solder as seen above. The
    GREEN wire is soldered to the micro switch "on/off" while the BLACK and RED wires are soldered as seen here. This switch allows the polarity of the frog match that of the direction of the route of the turnout. With the wires soldered on the switch, I then I apply another thin coat to the servo base and attach it to the module, ensuring the actuator wire is within the throw bar in the turnout. The glue gives me just enough time to center everything and I only have to hold it tight for about 30 seconds before it will stay in place. I let it fully dry overnight before using the servo however.
     
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  5. Jim Wiggin

    Jim Wiggin Staff Member TrainBoard Supporter

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    BM089.JPG
    Here we see the servo mounted. I have now installed the three wires into the associated terminal positions.

    BM090.JPG
    Here is a wide angle view. You can see the green frog wire coming out from above while the two power wires are coming from the power terminals. It may seam laborious, but on a small switching layout where locomotives are crawling through turnouts, it is absolutely essential. As such, the enjoy-ability along with the realism of the layout really shines.

    BM091.JPG
    Last but not least, I neatened up the wires coming from the junction box I showed earlier and used that C-clip at the bottom left side of the base to keep the wires both neat and help from the leads getting unexpectedly yanked from the boards. Yes, it's a strain relief.

    So there you have it, this is how I install the Tam Valley Servo Turnout Controls on my modules. I hope this was helpful to someone. If you have any questions, feel free to ask.

    What's next? Maybe the fiddle yard? Maybe scenery? Maybe we get structured. Stay tuned!
     

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