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reverse loop

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  • Member since
    October 2004
  • From: Colorful Colorado
  • 8,639 posts
Posted by Texas Zepher on Sunday, June 27, 2010 6:57 PM

MisterBeasley
I'm assuming you've basically got an oval with a pair of tracks crossing diagonally, right?

Insulate both rails of each of the cross tracks immediately after the turnout when they leave the main line.  You don't need to insulate the crossing.  I'd also recommend the PSX-AR.  It's all solid-state and it switches polarity very quickly.  It also serves as a circuit breaker to protect the reversing section power.

Strictly speaking, you should have a separate auto-reverser for each reverse section.  However, if you will never have a train going through both reverse tracks at the same time, you can get away with one.  They aren't cheap, particularly the good ones, so this is an opportunity to save a bit.

Depending on how long the crossover tracks are and what length of trains you run, you could have a problem.  An auto-reverser flips the polarity, if necessary, when the train enters the reverse section.  It will then flip it again when the train leaves the reverse section at the other end.  If the train is longer than the reversing track, it may be crossing both insulated joints at the same time, which is a situation the auto-reverser can't resolve.  Typically, this will only be a problem if you're running illuminated passenger cars, which can span the gap for a long time.  It may be a problem with any metal-wheeled car, though.

Could not have said it better or shorter so I won't try.   I would definitely use one reversing module for each reversing cut off.   Lighted cabooses or track powered FREDs could also cause the "long train" problem.
  • Member since
    September 2004
  • From: Dearborn Station
  • 24,281 posts
Posted by richhotrain on Sunday, June 27, 2010 10:39 AM

Hamltnblue

alberni pacific

I have a double reverse loop figure eight with an entry on both ends , any advice on wireing for dcc? i am using Atlas switches

 

Do you have a diagram or pic?  A standard figure 8 doesn't need a reverse loop. 

I agree.  As I draw a diagram of your layout as you describe it, I don't see any reverse polarities.  A track diagram or photo would help.

 

Alton Junction

  • Member since
    December 2004
  • From: Bedford, MA, USA
  • 21,483 posts
Posted by MisterBeasley on Sunday, June 27, 2010 9:43 AM

I'm assuming you've basically got an oval with a pair of tracks crossing diagonally, right?

Insulate both rails of each of the cross tracks immediately after the turnout when they leave the main line.  You don't need to insulate the crossing.  I'd also recommend the PSX-AR.  It's all solid-state and it switches polarity very quickly.  It also serves as a circuit breaker to protect the reversing section power.

Strictly speaking, you should have a separate auto-reverser for each reverse section.  However, if you will never have a train going through both reverse tracks at the same time, you can get away with one.  They aren't cheap, particularly the good ones, so this is an opportunity to save a bit.

Depending on how long the crossover tracks are and what length of trains you run, you could have a problem.  An auto-reverser flips the polarity, if necessary, when the train enters the reverse section.  It will then flip it again when the train leaves the reverse section at the other end.  If the train is longer than the reversing track, it may be crossing both insulated joints at the same time, which is a situation the auto-reverser can't resolve.  Typically, this will only be a problem if you're running illuminated passenger cars, which can span the gap for a long time.  It may be a problem with any metal-wheeled car, though.

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

  • Member since
    May 2008
  • 4,612 posts
Posted by Hamltnblue on Sunday, June 27, 2010 9:28 AM

alberni pacific

I have a double reverse loop figure eight with an entry on both ends , any advice on wireing for dcc? i am using Atlas switches

 

Do you have a diagram or pic?  A standard figure 8 doesn't need a reverse loop. 

Springfield PA

  • Member since
    January 2010
  • From: Denver, CO
  • 3,576 posts
Posted by Motley on Saturday, June 26, 2010 9:50 PM

Just get the PSX-AR from Tony's. You will need one for each of your reverse loops. They have detailed instructions on how to wire it. They are really easy to use, install, and work flawlessly.

PSX-AR DCC Specialties

Michael


CEO-
Mile-HI-Railroad
Prototype: D&RGW Moffat Line 1989

  • Member since
    December 2004
  • From: Rimrock, Arizona
  • 11,251 posts
Posted by SpaceMouse on Saturday, June 26, 2010 1:18 PM

 My first question would be: Why? There are probably much better designs for the money and space you have.

But to answer your question, you have to isolate both of your center legs. Then you have to be able to reverse the polarity of the legs with a switch. You can use manual switches or automated ones.   

Chip

Building the Rock Ridge Railroad with the slowest construction crew west of the Pecos.

  • Member since
    December 2008
  • From: bc
  • 5 posts
reverse loop
Posted by alberni pacific on Saturday, June 26, 2010 12:34 PM

I have a double reverse loop figure eight with an entry on both ends , any advice on wireing for dcc? i am using Atlas switches

david

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