George has been in touch with his excellent ‘how to’ on a model railroad crossing:
This diatribe is how I am providing crossing signals at roads crossing tracks.
There are IR sensors to sense incoming trains and the gates go up & down with flashing red lights. All gates are scratch built.
Commercial products ( very hard to get ) that do the same thing cost at least $180 a crossing with all the electronics and at 9 crossings this amounts to $1600 that I aint got.
First I cant thank John Frye enough for his submission to the infamous Al Lee site regarding IR signals because I would have never been able to do this without his brilliance.
The materials are available on Evil bay and Amazon and I figure it costs about $20 per crossing plus wiring and a lot of labor and swearing.
I am now looking into 3D printing the actual crossings because they’ll look & work better than the shop built prototype.
IR detector: Arduino PIC AVR IR Infrared Obstacle Avoidance Sensor Module Object Detector- about $2.00 ea.
Relay: 1 Channel Relay Module 5V Optocoupler LED for Arduino Pic ARM A. About $3.00 ea
Servo testor 3CH -about $3.00 ea. MG90S 9g Servo Motor Micro Metal Gear- About $4.00 ea. (2 rqd). Female ended 3 wire cables for servos.
This pic is of the prototype that actually works when I pass my hand between the IR bulbs.
The servo motor is under the foam, has a piano wire connect to it and the arm of the signal above.
The signal was made from wooden stirrers, hard maple for the base & turret & 18” ply for the arm. The lights will come later. Again I’m not content with the look and planning to 3D print this.
Below is a wiring diagram.
The three wires are cables made for servos and the squares are female connector ends.
The basic operation is: all servos are connected with a positive, a negative-, and a yellow signal current wire.
In this case we use the testor to provide the signal and the servo will revolve 90 deg back & forth in response to the testor input.
The IR detector senses a train then sends a signal to the relay, the relay turns the testor on or off and then the servos rotate to move the crossing gate up or down.
Each testor can work up to 3 servos and we have 2.
Model railroad crossing wiring:
This is a pic of the Servo testor. You remove the knob & blue cover and solder two wires as per the following
Right hand pic shows the back of testor with 2 wires soldered.
This pic is of an IR detector out of the box. We have to cut the white & dark LEDs and wire them so the bulbs will be placed on the layout facing each other, on each side of the track and hidden in the scenery.
This pic shows a test rig with the rewired IR bulbs and a functioning setup.
Put 5 V dc to the TB and all devices will show lights and if you place something between the IR bulbs the servo will rotate 90 deg.
There is a micro switch attached to the servo that will turn the blinking red lights on & off. The servo arm pushes the switch arm.
There are 2 servos below and 2 crossing signals above but only one servo needs a micro switch to work the lights on both signals.
This endeavor might seem daunting but it really is not bad once you built one.
It is time consuming, tests your soldering skills, and is fiddly connecting that piano wire from the servo to the crossing signal.
Because I dabble in S scale my crossings are to scale, look right, and except for a too quick action are my answer to proper crossing signals.
Now I just have to figure how to connect a clanging sound and I’ll have it just right. The criteria is it must not be pricey.
George from LI NY”
A huge big thank you to George for sharing his excellent ‘how to’ on his model railroad crossing.
As George says, some projects may look daunting, but broken down in to steps, they are too bad at all, and as George has shown, they can save you a small fortune.
There are quite a few posts on signal wiring on the blog now, and I’m pleased it’s helping a few of you out.
Here’s the post George mentions above on IR detection:
Also, these may help:
That’s all for today folks.
Please do keep ’em coming.
And if today is the day you get started on your layout, the Beginner’s Guide is here.
PPS More HO scale train layouts here if that’s your thing.