Reverse Loop Atlas controller HELP!!!

[plasticman]

Hello,

Problem here. I have a N scale layout with a reverse loop. Train runs good until it reaches the turnout then stops. I switch direction, push the train, then away it goes. It sucks doing this each time. I bought the atlas controller and dont have the faintist idea on how to wire this thing. I followed the schematics on the back and still nothing. Could someone please, please, please tell me how to wire this dang thing. Im so frustrated, its no longer funny or amusing. I am a novice at this, so please use very basic language and explain from start to finish on what to do. From how the track needs to be setup with insulators to the wiring of the controller to the power pack OR if there is a website to direct me to it. Thanks so much!

[ABC]

Insulate the reverse loop from the rest of the layout for starters. Then my next question is are you using E-z track or standard sectional or flex track (ie Atlas) or some other type(ie Unitrack, Trutrack)?

[pdlethbridge]

To start with, the reverse loop has to have insulators on both rails and at both ends of the loop. This link provides a lot of answers to your question
http://books.google.com/books?id=BaSerNUUAZkC&pg=PA56&lpg=PA56&dq=wiring+a+reverse+loop+with+atlas+controller&source=bl&ots=zulAWXaoed&sig=DWFcxJjR8uV6lxJxFRcMk3C6ID0&hl=en&ei=ZNs2S5uzNIuQlAfhkJyiBw&sa=X&oi=book_result&ct=result&resnum=3&ved=0CA4Q6AEwAg#v=onepage&q=wiring%20a%20reverse%20loop%20with%20atlas%20controller&f=false

[plasticman]

what in gods name is 35R feeders and do I need a selector switch as well? Still not making any sense.
I have 3 feeder wires hanging down under the layout, Im using atlas standard and flex track I have two turnouts, oposite of each other leading into the reverse loop. I only have one turnout that has the insulators just like the diagram shows. No other part of the layout has insulators. Do I need to put more on, if so, where? One feeder wire is by the turnout, the other is on the opposite side and another in the middle of the reversing loop.

[pdlethbridge]

35r is what their example is. Those wires would connect to the reverse loop which is insulated at both ends. When your train enters the loop, it will exit going in a different direction thus you would change the polarity of the track  outside the loop to match the polarity of the loop. Lets say that the rail nearest you is the plus rain and that would make the other rain the minus. And if the loop is to the right, that plus rail will run into the minus rail thus causing a short. Thats why the polarity has to be changed before the train leaves the loop


Every user of 2-rail DC knows the 'reversing loop' blues:
Including a reversing loop in a 2-rail DC layout leads to a short where the reversing loop ties into the main line.
Figure 1: Basic Reversing Loop

    * The only way to prevent this short circuit is to insulate both sides of the track. A single two-rail gap is not enough, since a passing engine will short the rail through the electrical pick-up on both sides of the gap. Therefore, the track has to be gapped on both sides of the reversing loop. One still has to ensure that the rails are not short circuited upon entry or exit of the reverse loop.
    * Usually, the polarity is selected such that there is no short circuit upon entry into the loop. While the train is in the loop, the polarity is changed, so that there is no short circuit at the exit of the loop.
A good reference to keep is here. http://www.nmra.org/beginner/wiring.html

[plasticman]

ok, Im starting to follow you, but how do I connect the wiring to the atlas controller?? I tried what the schematics have showed me, but nothing. Its a small layout 2X4. Do I only need one feeder wire? If so, where would it be located? I actually have three, spread thru out the N scale layout. Thanks so much!

[pdlethbridge]

If you only have one train, Then you would need 4 wires. 2 for the reverse loop and 2 for the rest of the layout. They would be wired as follows: On the three terminals at the top the left would be the layout common, the other 2 would be the reverse loop and only the reverse loop. On the right side of the controller are 4 places for wires. Only use the top one for the other wire to the mainline opposite the common. On the top left 2 terminals hook up your power pack. When you operate the train, use the power pack only for speed and use the controller for direction. On the controller, the top left toggle is only for direction on the main line and the middle right toggle is only for the reverse loop.

[Joe Satnik]

Dear PM,

Go buy "The Complete Atlas Wiring Book", which is Atlas book #12.

Excellent descriptions and track-wiring diagrams for reverse loops.

Some reverse loop circuits are shown at this web page (scroll down):

http://www.building-your-model-railroad.com/model-railroad-wiring.html#blockwiring 

Atlas "Twin" switches (#210) contain 2 DPDT switches that are pre-wired to reverse the polarity, ideal for reverse loop wiring. 

Hope this helps. 

Sincerely,

Joe Satnik