Operating model railroad crossing gates How to install working crossing gates on a model railroad layout.

Create realistic crossing gate operation using Tortoise™ slow motion switch machines.

The Signal This example shows how to make operating crossing gates with O scale signals by NJ International driven by Tortoise™ switch machine motors. The motors move the gate arms at realistic speed when operated at 4.5 to 6 volts, such as provided by the MRX1 crossing signal controller.   HO scale and N scale installations are shown below.   The NJI gates come with an actuating wire that extends out the bottom of the base. Unfortunately, this wire is attached right at the gate's pivot point, so it requires a lot of force to move and has very short range of motion.   This wire is soft, so it can be removed with a firm, steady pull with pliers.   Drill a small hole in the crossing arm counterweight as far from the arm's pivot as practical. The goal is to create as much leverage as possible so the motors can provide smooth motion. The hole should be just large enough for your actuator wire. Piano wire, 0.015 or 0.025 in. dia. works well.   Mount the signal by shoving a length of 3/8 in. brass tubing firmly into the base. Run the wires through the tube. Drill a 3/8 in. hole in the layout, then place the signal. The Mechanism To provide vertical drive motion, the Tortoise™ switch machine must be mounted horizontally under the layout. Figure 2 shows how to do this.   Fig.2 shows the use of an 'L' bracket to mount the Tortoise switch machine motor.   A transverse wire connects the actuating wire to the motor output. The transverse wire allows the mechanism to have more 'give.' The movable fulcrum allows you to adjust the range of motion and change the mechanical advantage.   Alternatively, Circuitron's Remote Signal Activator kit may be used to mount the Tortoise™ switch machine motor and connect it to a crossing arm.   Your careful efforts installing working crossing gates will reward you and your visitors many times over.

Fig.1 - Actuator wire connects to a hole drilled in the crossing arm counterweight. Fig.2 - Mounting the motor under the layout.

---

HO scale working crossing gates

Josta refined the Tortoise™ mounting method and took these photos on his HO scale layout. He is using NJ International signals with crossing gates.
 

Josta ran the gate arm actuating wire at a 60 degree angle. He then mounted the Tortoise switch machines under the layout base at a 60-degree angle as well. He says,

"I used 0.030-inch music wire for the horizontal lever of the motor, and another 0.030 section of music wire for part of the vertical pushrod. These two wires are connected with tight loops at each end as the photo shows. Then I used a cable clamp (available at auto parts stores) to clamp the 0.015 music wire from the NJ gates to the 0.030 wire from the motor. Just loosen the clamp to move the gates to the desired up and down points.
 
"I move the fulcrum as needed to give the desired range of motion. If there's too much play due to the flexing of the 0.015 wire, just move the cable clamp up closer to the gate; that's why I use 0.030 wire as it's stiffer."

The actuating wire is 0.015-inch music wire, placed on the back side of the signal where it is not so easily seen.
 
See the smooth action of Josta's excellent installation in his YouTube video:
[http://www.youtube.com/watch?v=LeST0GnjOeg]
 

N scale crossing gate installation

David Bilek placed this N scale NJI crossing gate and its Tortoise™ motor on a lift-out base to simplify assembly and maintenance. He can also take it with him when his layout moves. Believe it or not, David added LEDs to those N scale crossing gate arms and wired them to a MRX1 crossing signal controller so they flash in prototypical style. Amazing work, David!

Home | Detectors | Signal Flashers | Bell Ringer | Power Relay Crossing Signals | Power Supplies | How to order | Contact us | Links © copyright 2009 - 2011 Azatrax, Longmont, Colorado