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reverse loop isolation locations

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  • Member since
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reverse loop isolation locations
Posted by Roadie on Thursday, August 23, 2012 4:06 PM

http://i288.photobucket.com/albums/ll197/RoadieSL/IMG_1830.jpg

Here is a link to a section of my layout as you can see it is a loop with a yard in the center and a main line connection to it from the outside. My problem is Im not sure where to place the isolation joints in the layout 

I have place them where I show the auto reverse seemed to work for one night them it stopped working I can still hear the relay switch in the Digitrax auto reverse unit. But the loco just get to the switch on the outside of the loop ans stops.  My system is DCC Digitrax Zephyr 

Please give me some advise as to where I need to place the isolation joints and how to wire it up

thanks Huh?

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Posted by Phoebe Vet on Thursday, August 23, 2012 4:14 PM

Assuming the place the tracks cross is a diamond crossing and not a switch, there is no reversing section in the section you posted.  We need to see more of the layout.

Dave

Lackawanna Route of the Phoebe Snow

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Posted by Roadie on Thursday, August 23, 2012 5:36 PM

sorry I drew it wrong the loop returns to the diverging side of the switch if I don't have isolation joint on the diverging side of the switch there is a direct short.

I will try to get a full picture of my layout ASAP but I am sure there is a reversing problem here

Thanks

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Posted by richhotrain on Thursday, August 23, 2012 8:51 PM

As Dave has said, there is no reversing section in the track diagram that you have drawn.

If you hear the AR-1 clicking or your DCC system is shorting, then there is a problem somewhere, so we need to see more of your layout.

Rich

Alton Junction

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Posted by maxman on Thursday, August 23, 2012 10:09 PM

Roadie
I have place them where I show the auto reverse seemed to work for one night them it stopped working I can still hear the relay switch in the Digitrax auto reverse unit. But the loco just get to the switch on the outside of the loop ans stops .

As the others have said a full picture, or at least a corrected diagram, is required.

However, when you say it gets to the switch on the outside of the loop and stops, which switch are you talking about?  Is it the one at the left side of the diagram?  If so, what manufacture of turnout is that?  And, assuming that you really have a loop, does the loco run properly with that left side turnout thrown for the loop, but then not run if the turnout is thrown the other way?

Whatever the case, I think you need another set of gaps at the frog end of the diverging route at that turnout on the loop left side.

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Posted by Roadie on Friday, August 24, 2012 12:17 AM

http://i288.photobucket.com/albums/ll197/RoadieSL/IMG_1833.jpg

Here is a link to my full layout if you look close the problem where I am getting a dead short and where I have placed isolation plastic track connection  sorry about the poor copy. 

I know to many tracks please look it over and advise 

Thanks RodieSl

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Posted by richhotrain on Friday, August 24, 2012 6:05 AM

Roadie, the short is occurring at that right hand turnout below the crossing.  As the divergent track of that right hand layout traverses the crossing and runs diagonally up to the right hand turnout beyond those stub end yard tracks, there is a mismatch of polarities.

One way to solve the problem is to gap the rails of the divergent track on each of those two turnouts. That would create a reversing section that includes those stub end yard tracks.  The only problem with that solution is that the track between the gaps may not be long enough unless you are running single locomotives and rolling stock with plastic wheels.

A better solution might be to gap the rails of the divergent track on the lower right hand turnout and then also gap the rails of the straight end of that same turnout where the track heads left on your diagram.  To completely isolate the resulting reversing loop, you would also need to gap the rails on the other end of the loop, somewhere near the top of your track diagram.  The advantage of this solution is the creation of a larger reversing section to accommodate longer trains.

Can you add a photo of your track diagram to completely show the left side of your layout?  That would help to determine where the remaining gaps should be placed.

Rich

Alton Junction

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Posted by rrinker on Friday, August 24, 2012 6:45 AM

(made link clickable - use the chain icon to insert links)

http://i288.photobucket.com/albums/ll197/RoadieSL/IMG_1833.jpg

Here is a link to my full layout if you look close the problem where I am getting a dead short and where I have placed isolation plastic track connection  sorry about the poor copy. 

I know to many tracks please look it over and advise 

Thanks RodieSl

           --Randy


 

Modeling the Reading Railroad in the 1950's

 

Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.

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Posted by Roadie on Friday, August 24, 2012 8:35 AM

Here is a crude drawing of the loop 

The switch that I have isolation joints now was a dead short until I placed the isolation joints

the other isolation joints for the loop are on the 12.5 degree crossing then I placed a Digitrax auto reverse  per their drawing. 

As the loco gets to the switch with thw isolation joints it just stops if I push it through the switch it will take off

When the loco is on the isolation joint I can hear the auto reverse relay switching 

Is this the right place for the isolation joints?  Do I need more? Do I need any?

http://i288.photobucket.com/albums/ll197/RoadieSL/Loop1.jpg

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Posted by maxman on Friday, August 24, 2012 9:30 AM

Roadie

Here is a crude drawing of the loop 

The switch that I have isolation joints now was a dead short until I placed the isolation joints

the other isolation joints for the loop are on the 12.5 degree crossing then I placed a Digitrax auto reverse  per their drawing. 

As the loco gets to the switch with thw isolation joints it just stops if I push it through the switch it will take off

When the loco is on the isolation joint I can hear the auto reverse relay switching 

Is this the right place for the isolation joints?  Do I need more? Do I need any?

http://i288.photobucket.com/albums/ll197/RoadieSL/Loop1.jpg

The different views are confusing.  But my opinion is as follows. You show one set of gaps at the 12-1/2 degree crossing.  Lets say that's the start of the loop.  The second set of gaps is at that crossover.  I believe that this is also correct.  However, that turnout to the crossover is really just a branch off the loop.  If you start at the 12-1/2 degree crossing and work your way around the loop, bypassing that crossover, you should come to the spot where the loop really ends.  You would need gaps at that point also.  Not knowing what's to the right of the crossing, you could probably get away with installing another pair of gaps right where the loop connects to the crossing just below where you show the first pair. 

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Posted by richhotrain on Friday, August 24, 2012 3:57 PM

Roadie, I am going to repeat what I said earlier.  The short is occurring at that right hand turnout below the crossing.  As the divergent track of that right hand layout traverses the crossing and runs diagonally up to the right hand turnout beyond those stub end yard tracks, there is a mismatch of polarities.

One way to solve the problem is to gap the rails of the divergent track on the right hand turnout beyond those yard tracks and also gap the rails on the end of the crossing just before the yard tracks.  That would create a reversing section that includes those yard tracks.  The only problem with that solution is that the track between the gaps may not be long enough unless you are running single locomotives and rolling stock with plastic wheels.

If you need a longer reversing section, gap the rails on the end of the crossing just before the stub end yard tracks.  Then, gap the rails on that right hand turnout above the yard tracks where the turnout connects to the track running around the right side of your layout.  To completely isolate the reversing section, you will need a third set of gaps somewhere to the left of that right hand turnout above the yard tracks.  The advantage of this solution is the creation of a larger reversing section to accommodate longer trains.

Take a look at your track diagram below.  The blue and red circles indicate the location of the gaps if you want a short reversing section.  Alternatively, the blue and green circles indicate the location of the gaps if you need a longer reversing section.  With the longer reversing section, don't gap the rails at the location of the red circle.

Rich

Alton Junction

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Posted by Roadie on Saturday, August 25, 2012 7:37 PM

If I gap them for the longer section do I need  a auto reverse and how should it be wired?

Thanks

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  • From: Dearborn Station
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Posted by richhotrain on Saturday, August 25, 2012 9:30 PM

Roadie

If I gap them for the longer section do I need  a auto reverse and how should it be wired?

Thanks

Yes, an auto-reverser is the best way to deal with the reverse polarity problem.

A pair of feeder wires from the main bus wires should be connected to the input side of the auto-reverser.

All of the feeder wires inside the reversing section must be connected to the output side of the auto-reverser.

Be certain that no feeder wires inside the reversing section are connected to the main bus wires.

Rich

Alton Junction

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