A Better Servo Mount

If you are using servos to run your turnouts, you’ve probably discovered that there are not a lot of mounting solutions on the market appropriate for model railroaders.

Although several manufacturers (notably PECO and Walthers) now offer servo-based turnout motors, they are primarily designed to work with proprietary turnout control systems and/or come loaded with auxiliary contacts that the you doen’t necessarily need (esp. if like me you use your Arduinos for all power management tasks). These overblown mounts greatly expand the footprint of the turnout motor negating the space saving advantages of servos.

There have been no simple, low profile mounts on the market useful for model railroading. So I’ve relied on a simple hot glue and styrene strip mounting method that works …. until it breaks.

An original L&NC Hot-Glue-And-Styrene mount.

I’ve been somewhat frustrated on this issue. Until now.

The Ultimate Servo Bracket, available with and without servos from Smart Hobby LLC, is a genuine model railroader’s solution to the servo mounting problem, offering multiple ways to mount and link servos to your turnouts or other moveable objects.

FULL DISCLOSURE: Blog reader Jack gave me a couple of early prototypes to work with and comment on. I was pleased enough with the prototypes to purchase a batch from the first production run.

Rotational Motion

The bracket comes assembled in a way that converts the side to side motion of the servo to rotation of the wire. In this mode, the bracket can be mounted on the underside of the layout, with the wire coming up through the layout base. Bending the wire in any one of several ways converts the motion back to linear for moving turnout points or other uses.  The company website has extensive instructions on using this method to create hidden turnout linkages.

If you have rotating switch stands on the layout, they can be automated from below with the bracket in rotational mode.

Rotational motion, without reconversion, is also useful for general layout animations, such as moving signs, doors or other objects that can be moved by rotation. So the bracket in rotational mode has many potential uses beyond turnouts.

Linear Motion

Turnout points move in linear fashion, and there are advantages to a direct linear attachment. In N scale, the point rods are small; a wire from below pushing it from side to side is effectively hidden and has little risk of getting fouled by loose ballast.

The two brackets of the Ultimate Servo Bracket.

As you can see in the photo, there are two very small holes in the base plate for the wire, one on each side of the bend.  The small hole on the side with 4 large mounting holes is the one to use as a fulcrum for linear motion.

Mounting the bracket is straight forward: first you need to drill your hole for the wire to reach the turnout. Since the bracket provides the fulcrum, the hole can be large enough to let loose ballast slip through.

Preparing a Turnout for the Servo wire.

In the above new installation, you can see where i marked the position of the points bar and drilled an elongated hole for the wire.

Turnout Installed; the wire and hole are well hidden.

Returning to the retrofitting of the bracket where an old one had broken, since the hole was already in place, I just threaded with wire through the fulcrum hole of the base plate, then into the hole in the layout base, like so:

Thread the wire through the base plate and into the layout.

You may need a helper to guide the wire through the hole in the turnout bar.

The wire coming up through the layout base.

Next position the base plate so that the wire moves the turnout easily without binding. Note that the long side of the bracket must be parallel to the plane of motion for the wire. A little duct tape held the plate in place while I drilled pilot holes.

Then,  screw the servo plate to the layout through the prepared mounting holes.

Finally, trim the wire with a Dremel Cut-off disk (NOTE: this is “hard” wire and you will need a hard wire cutter or a cut-off disk. You will get sparks with the cut-off disk: USE EYE PROTECTION!)

Easy to install. Flexible mounting and motion options. Just what is needed for model railroaders who want a space efficient servo mounting system for their turnouts or other animated objects.

 

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