Tortoise Switch Machine Non-Derail

The diagram shows a plain diode and since the Tortoise runs on DC only, it is an absolutely necessary part of the circuit.  Putting straight AC track power to a Tortoise motor may fry it in short order (no pun intended).

good afternoon

The tortise Switch machine doesn't need non-derail wiring. the points are spring loaded and will move if you run thru the wrong way. 

clem

You might want to look at this type installation I used it on several layouts and it works fine . It uses the Atlas # 6924 non-derail circuit board.

I'm curious if anyone has actually wired their Tortoise machines for the NON-Derail operation?

I keep the spring tension tight, especially on switches that are hidden and hard to reach. So cars that are very light (like a caboose) won't roll through the spring loaded points.

I power the Tortoise with a DC wall wart, so right now there are only 2 wires going to each Tortoise, and I would like them to operate with a NON-Derailing feature for our hidden reverse loop. 

I operate without the non-derail and rarely have a problem pushing through. I use the same spring wires as issued except longer.

I also use a 12 VDC wall wart to power my 17 Tortoise.

We upgraded to a much heavier spring wire because of the extra length needed for the 1 1/2" of plywood, homasote, and cork.

The engines will push through the points no problem, but most of the cars won't. Maybe I'll try to loosen the tension on the wire, or even replace it with a smaller one. 

Possible trouble:

(1.) Accessory common and Track common need to be the same/connected. 

(2.) Isolated rail section should be long enough to allow both trucks per car, a continuous uninterrupted connection. 

(3.) Way back from the switch.

Are any of you using the other relay contacts in the tortoise machine to control a dwarf signal indicating switch position ?  

I, too, have been searching for a way to make Tortoise switch machines operate in non-derail mode.  I am posting a circuit that I put together and tested.  You have to use an AC powered double-pole, double-throw mechanically latching relay.  I used one sold by Azatrax, called an LARY-AC.  It has to be latching, because the Tortoise has to have power applied to it continuously.  This is actually a pretty simple setup.  I also ran connections from the insulated rails to the control panel so I could throw the turnout without a train being present.  I used single-pole, double-throw, momentary contact switches to do that.  Later I will wire up the signals and post a schematic when I've had a chance to test it.  Here are some pics (hopefully - this is my first post)

Old bathboard never dies - it just gets made into electrical panels!

I've been using longer pieces of original size wire to operate my 40 Tortoise machines for more than 8 years.  This is also provides non-derailing.  There has never been a derailing resulting from a car being too light failing to push the moveable rail aside. It's imperative that the tension be carefully adjusted to be equal in both positions and that the switch throws easily and smoothly.

One caveat with this scheme involves switches that might require power routing to prevent stalling (typically double slip switches, #8 switches, etc.).  Trying to run thru these when the points are mis-aligned will produce a dead short so electrical non-derailing  or extra caution are required.

We had a chronic problem with people forgetting to close a turnout from the staging yard to the main. I finally put an automatic throw on it using the Azatrax MRD2-Turnout controller. It has an output terminal that sends out +5 or -5 volts DC to a Tortoise motor in response to the infrared sensors in the track. Works like a charm. There's a close sensor on the staging yard track immediately behind a dwarf signal which normally indicates red. When the operator has verified nothing's coming, he slightly "runs" the signal and hits the infrared sensor which changes the signal to green and slowly moves the turnout points in advance of the train's arrival. When the next train comes through the yard, it hits the other sensor and throws the turnout back. Works great.

you're correct, but there are a couple advantages.  with a non-derailing setup, you needn't worry about reversing direction through a switch if the train isn't all the way through or if you merely want to reverse the motion to clear a main and it also helps to evenly wear a mainline with reversing loops at either end flip-floping the direction through the loop each time.

cheers...gary