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Layout with Two Reverse Loops

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  • Member since
    July 2006
  • From: Farmington Hills, Michigan
  • 37 posts
Layout with Two Reverse Loops
Posted by billybob757 on Sunday, February 5, 2012 8:31 AM

Question - I have a DC powered layout designed with two reverse loops on each end of the layout .

Every three to four feet I have used the Atlas terminal joiners as feeder wires.  I have cut the wire to a short length, soldered to 18 gage wire to be soldered to the main wire feed which I am planning on 12 gage.. 

For each reverse loop, wire would come off the transfomer to each of the Atlas twin switcch.  One side of the switch would route the 12 gage wire to the reverse loop, the other side would route the 12 gage wire to the main line..

My dilema is how to wire the main line between the two twin swithces?

I do have the Atas wire books, but there is nothing I can find about two reverse loops.

I would greatly appreciate it if anyone has words of wisdom.

Thank-you in advance

Bill

  • Member since
    July 2003
  • From: Sierra Vista, Arizona
  • 13,757 posts
Posted by cacole on Sunday, February 5, 2012 9:39 AM

With DC power, you must stop the train inside the loop, change the polarity of the loop with the toggle switch, and also reverse the direction of travel with your throttle to reverse the polarity of the main line as the train exits the loop.

 

  • Member since
    October 2004
  • From: Colorful Colorado
  • 8,639 posts
Posted by Texas Zepher on Sunday, February 5, 2012 1:32 PM

billybob757
Question - I have a DC powered layout designed with two reverse loops on each end of the layout ....Every three to four feet I have used the Atlas terminal joiners as feeder wires.  I have cut the wire to a short length, soldered to 18 gage wire to be soldered to the main wire feed which I am planning on 12 gage..

Irrelevant to your question.   But irrelevant to my answer - why 12 gauge?  That seems huge (not to mention hard to deal with). 

For each reverse loop, wire would come off the transfomer to each of the Atlas twin switch.  One side of the switch would route the wire to the reverse loop, the other side would route the  wire to the main line..

My dilema is how to wire the main line between the two twin swithces?

???  You just said "the other side would route the wire to the mainline".  That is exactly how to wire the main line between the two twin switches. 

If you want to have two switches for the main line (one on each side of each of the twins) then the twins have to be in series with each other.  In that case it would get tricky knowing how to switch the 2nd reversing loop.    My recomendation is to just ignore the second switch connection on the second twin.   Only three DPDT switches are needed for one main line with two loops.    When the train goes into the second loop, use the main line switch on the first twin to change the mainline polarity,

  • Member since
    December 2004
  • From: Bedford, MA, USA
  • 21,483 posts
Posted by MisterBeasley on Monday, February 6, 2012 11:57 AM

cacole

With DC power, you must stop the train inside the loop, change the polarity of the loop with the toggle switch, and also reverse the direction of travel with your throttle to reverse the polarity of the main line as the train exits the loop.

 

This is really going to depend on how your layout is wired.  I'm guessing that you are running a power-pack with a built-in throttle, which connects to your 12-gauge track bus.  If that's the case, you need 3 double-pole, double-throw (DPDT) toggles.  An Atlas Twin provides two DPDT toggles.  If you only run one train, you can get away with wiring the two loops to the same toggle, but the extra toggle is pretty cheap.

Assuming you're using the Twin for your main-line direction control as well, run the 12-gauge bus wires directly from the power pack to the base connections of the Twin(s), which are the center posts of a DPDT toggle.  On a Twin, the two sets of center posts are wired together.  Run another pair of 12-gauge bus wires from the top terminals of one Twin toggle to your main line, and the other set Twin gets connected to the reverse loop, or to both loops if ou choose to run it that way.  If you go with two Twins, then connect one of the outputs of the second Twin to your second reverse loop, and leave the other empty for expansion.

Each of the toggles on a Twin will now control the direction of travel on its part of the layout.  The Main will control whether you're going left or right, and the loop toggles will control whether you're going clockwise or counter-clockwise.

Use the Main toggle to send the train towards one loop.  Based on the position of the turnout, select the position of the loop toggle to match the direction of travel through the loop.  Once the train is entirely in the loop, flip the turnout and the Main toggle.  The train will then exit the loop and will be going the right direction on the Main so there is no need to stop the train in the loop.

It takes an iron man to play with a toy iron horse. 

  • Member since
    July 2006
  • From: Farmington Hills, Michigan
  • 37 posts
Posted by billybob757 on Wednesday, February 8, 2012 3:49 PM

Thanks to all who provided the information.  Now I know what I will be startring this weekend.

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