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Help with Reversing Loops Please

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Posted by Anonymous on Thursday, July 24, 2014 12:39 PM

Is the locomotive shorting while touching any part of a turnout?  Are you using the standard 202S caboose industries ground throw or a different one?

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Posted by Anonymous on Thursday, July 24, 2014 12:33 PM

Do you have a volt meter with a continuity checker?  If so turn off layout power, commince finding shorts.  Do you have any other feeders than the ones shown in the picture earlier?

 

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Posted by trafficdesign on Thursday, July 24, 2014 12:32 PM

richhotrain

The OP is building a test loop right now to verify operation of the AR-1.

I suspect the AR-1 is either malfunctioning or outright faulty.

 

 
Test complete and AR1 is functioning perfectly. Now what???
 
AR1 Test
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Posted by Anonymous on Thursday, July 24, 2014 11:51 AM

The straight piece of track that i described earlier 15min,  an physical loop longer.  Also he may have discovered that the AR-1 was faulty and went directly to the LHS to get a new one.

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Posted by richhotrain on Thursday, July 24, 2014 11:39 AM

Hey, where is trafficdesign?  Surprise

How long does it take to set up a reverse loop anyhow?   Super Angry

Rich

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Posted by richhotrain on Thursday, July 24, 2014 11:34 AM

LOL

For 45 years, my American Flyer trains were holed up in a cardboard box in the attic until I rescued them and restored them four years ago.

I set up a small AF layout on a 8' x 16' table adjacent to my HO scale layout for a couple of years, but I took it down last year to open up the space.

Rich

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Posted by Anonymous on Thursday, July 24, 2014 11:31 AM

What do you mean as a kid, its sitting in my closet right now, only reason Im running HO scale is I cant fit O72 curves everywhere I need them for my Hudsons and Niagara.  Also the live-in girlfriend/fellow model railroader said I couldn't use that much space Dots - Sign

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Posted by richhotrain on Thursday, July 24, 2014 11:21 AM

BMMECNYC

I have to keep things simple because I am a simple minded 3-rail O-guage guy

 

As an American Flyer guy as a child, with its 2-rail realism, I can understand you feeling simple minded, being stuck with that 3-rail O-gauge crap as a kid.   LaughLaughLaugh

Rich

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Posted by richhotrain on Thursday, July 24, 2014 11:17 AM

I hear ya.

I suppose that among experienced users of reversing sections, there are two schools of thought: those who want everthing outside of the reversing section wired the same way and those for whom it doesn't matter as long as the "outer rail" is wired one way and the "inner rail" is wired the other way.

Rich

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Posted by Anonymous on Thursday, July 24, 2014 11:09 AM

Hmm

If I were doing something similar (track plan wise), the only way I would be able to keep the wiring straight is to have the wiring the same starting from the farthest wire, ie the wire farthest is red, the closer one is blue, and have that consistancy everywhere except the loops, which would then revert to left rail/right rail top down/or bottom up color coding and connected to the reverser.  This would require a second reverser.

I have to keep things simple because I am a simple minded 3-rail O-guage guy with my NYC stuff and reverser is a word that just arrived inn my model railroading vocabulary.

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Posted by richhotrain on Thursday, July 24, 2014 11:04 AM

Each and every rail on the Atlas Custom Line turnout is powered at all times.

Each crossover is simply two turnouts connected together, so each and every rail is powered.

Rich

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Posted by Anonymous on Thursday, July 24, 2014 11:02 AM

richhotrain
 
BMMECNYC

Do the rails on the atlas turnouts he is using have power on the diverging end, and are the 2 inside rails (the ones that connect to the frog) on the diverging end close enough that there is a short the AR-1 cannot correct?  The op might also check his track work/wiring with a volt meter with a continuity setting to see if there is a dead short somewhere. 

 

 

 

The Atlas Custom Line turnouts have an isolated dead frog, and they are not power routing.  So all of the rails are powered at all times.  I have tons of Atlas Custom Line turnouts on my layout, and the rails are not close enough for wheel shorts to occur, at least not on the standard RH and LH turnouts.

Good idea on the possibility of a dead short.  If any feeders are inadvertently reversed, a dead short can result.

Rich

 

 

The part of track after the frog but before the insulated rail joiners should be dead then if I am understanding you correctly.  What about on the crossover?  Are those rails powered?

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Posted by richhotrain on Thursday, July 24, 2014 10:58 AM

BMMECNYC

Do the rails on the atlas turnouts he is using have power on the diverging end, and are the 2 inside rails (the ones that connect to the frog) on the diverging end close enough that there is a short the AR-1 cannot correct?  The op might also check his track work/wiring with a volt meter with a continuity setting to see if there is a dead short somewhere. 

 

The Atlas Custom Line turnouts have an isolated dead frog, and they are not power routing.  So all of the rails are powered at all times.  I have tons of Atlas Custom Line turnouts on my layout, and the rails are not close enough for wheel shorts to occur, at least not on the standard RH and LH turnouts.

Good idea on the possibility of a dead short.  If any feeders are inadvertently reversed, a dead short can result.

Rich

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Posted by richhotrain on Thursday, July 24, 2014 10:53 AM

One thing about the two auto-reverser issue with one in each end loop.

The only point of reverse polarity is at the site of the two crossovers.  So the only reason to turn the two end loops into reversing sections is to be able to wire the rest of the layout in phase. But, then you need two auto-reversers instead of one, seems kind of a waste when one will do.

The main objection to to treating the two crossovers as a reversing section is the possibility of two trains simultaneously entering and exiting the reversing section.  So, we came up with the idea of the third track, the so-called bypass, to minimize that possibility and, I might add, to provide some additional operating interest.

Rich

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Posted by Anonymous on Thursday, July 24, 2014 10:45 AM

I have to get out of the habbit of editing my posts.  Do the rails on the atlas turnouts he is using have power on the diverging end, and are the 2 inside rails (the ones that connect to the frog) on the diverging end close enough that there is a short the AR-1 cannot correct?  The op might also check his track work/wiring with a volt meter with a continuity setting to see if there is a dead short somewhere. 

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Posted by richhotrain on Thursday, July 24, 2014 10:42 AM

BMMECNYC

It is very likely, I also agree with you on the wirings apparent correctness.  I would ask however if there are other feeder drops.  Could it be that there is enough power loss through the rail joiners that the AR-1 isnt sensing the polarity mismatch before it becomes shorted or trips CB. 

 

It is possible, but I doubt that is the problem.  I often only run one set of feeders to a reversing section.

I do wonder if there are any misplaced feeders though that might cause the AR-1 to go beserk.

Rich

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Posted by Anonymous on Thursday, July 24, 2014 10:39 AM

It is very likely, I also agree with you on the wirings apparent correctness.  I would ask however if there are other feeder drops.  Could it be that there is enough power loss through the rail joiners that the AR-1 isnt sensing the polarity mismatch before it becomes shorted or trips CB. 

I know nothing about these turnouts that he is using, could it also be that the diverging rails exiting the points are being shorted.  I have had this problem with PECO turnouts.  The plastic insert does not extend far enought down the middle of the 2 diverging rails and shorts when wide metal wheel treads hit them. 

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Posted by richhotrain on Thursday, July 24, 2014 10:35 AM

I believe that it was Randy who first suggested two auto-reversers, one in each end loop.  It is just another option.

The OP is building a test loop right now to verify operation of the AR-1.

It seems to me that his gaps are appropriately placed and his wiring is correct.  So, not sure why it isn't working.

I suspect the AR-1 is either malfunctioning or outright faulty.

Rich

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Posted by Anonymous on Thursday, July 24, 2014 10:27 AM

What was the objection to putting 2 reversers, 1 at each loop?  Given a 24" Radius, that would allow a 9ft reversing section with minimal headache.  Granted I do like a challenge.  Additionally were are we with the OPs original problem of the dead short?  Good news about the about the south main bypass is that the OP now has a passing siding or MOW siding if he goes with the loop reverser idea.  However I suspect that we will find the location of the short momentarily when he finishes his test loop.

Theoretically you only need a 3ft piece of track stapled to a 2x4 to test your reverser.  Cut it into 3 gapped blocks 1 ft long.  the outside 2 sections have opposite polarity ie Blue to right hand rail on 1 section, blue to LH rail on 3rd section.  Middle section connected to output of AR-1.

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Posted by richhotrain on Thursday, July 24, 2014 10:20 AM

He will have a problem if one train is entering while the other is exiting.

That is why I suggested that third track, what the OP calls the South Main Bypass, to at least reduce the possibility of conflicting traffic in and out of the reversing section.

Rich

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Posted by Anonymous on Thursday, July 24, 2014 10:17 AM

rrinker

 It's not a holdover. If you have success with a less than train length reverse section, then you are not running loco consists longer than the reverse section, or are not using lighted passenger cars. Unless you cut gaps with laser-guided 1/10000 of an inch precision, they will never be exactly parallel and it will be very unlikely that the distance between the sets of gaps is enough to allow multiple metal wheels to exactly touch all the gaps at the same time. SO in a sense, it does work. But try building a loco consist longer than the reverse section, or jsut have 2 independent locos and try to cross both sets of gaps at the same time. It won't work - it CAN'T work because the reverser would have to set the phase of the reversing section in both directions at the same time.

              --Randy

 

Wont the OP have the same problem now if 2 trains are running?  1 on south bound, one on nortbound, following the other around the loops?  One locomotive exiting, one entering?

 

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Posted by Anonymous on Thursday, July 24, 2014 10:14 AM

richhotrain

Here is what the PSX-AR manual has to say:

The length of the reversing section of track between the gaps should generally be longer than the longest train that will use the section of track.

Rich

 

Cut and pasted from further on in the PSX-AR manual

 

If your train is longer than your reverse block and has metal wheels, you may need to cut additional gaps into the reverse section. Simply cut another set of gaps at both ends of the reverse sections inside of the original gaps. The distance between these gaps and the original gaps should be longer than the wheelbase of any metal truck.  Note that one end of the reverse section will be aligned with normal polarity track power while the opposite or other end will have a polarity mis-match and require the reverser to act.

 

 

 

 

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Posted by rrinker on Thursday, July 24, 2014 10:02 AM

 It's not a holdover. If you have success with a less than train length reverse section, then you are not running loco consists longer than the reverse section, or are not using lighted passenger cars. Unless you cut gaps with laser-guided 1/10000 of an inch precision, they will never be exactly parallel and it will be very unlikely that the distance between the sets of gaps is enough to allow multiple metal wheels to exactly touch all the gaps at the same time. SO in a sense, it does work. But try building a loco consist longer than the reverse section, or jsut have 2 independent locos and try to cross both sets of gaps at the same time. It won't work - it CAN'T work because the reverser would have to set the phase of the reversing section in both directions at the same time.

              --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 richhotrain on Thursday, July 24, 2014 9:48 AM

Here is what the PSX-AR manual has to say:

The length of the reversing section of track between the gaps should generally be longer than the longest train that will use the section of track.

Rich

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Posted by richhotrain on Thursday, July 24, 2014 9:45 AM

BMMECNYC
 

Read the pg 9 of the PSX-AR instructions for having a reversing section shorter than the train length. 

here:

http://dccspecialties.com/products/pdf/man_psxar.pdf

Someone may correct me if im wrong but that should work as well.

I still contend the the reversing section does not have to be longer than the train.  I have run 30ft long trains through  a 3ft reversing section (metal wheels) without issue.  (I do not know which reverser is installed on that particular club module.

 

I think a lot depends upon the type of auto-reverser and the nature of the equipment being run on the track.

I had been a huge fan of the Digitrax AR-1 for years, having installed five of them on my layout to deal with multiple reversing sections.  But, when I decided to add PSX circuit breakers and divide my layout into a series of separate power districts, I suddenly had no end of problems with the AR-1's.  So I replaced all of them with PSX-AR units.

The AR-1 needs fine adjustments to the TTC screw to permit trains longer than the reversing section.  A loco or consist with metal wheels needs to be shorter than the reversing section.  Lighted passenger cars need to fit inside the reversing section as well.  A lighted caboose needs to fit inside the reversing section as well.  Unlighted passenger cars with metal wheels may or may not cause problems if the entire train is longer than the reversing section.

My recent experience is that the PSX-AR is more tolerant when it comes to unlighted passenger cars with metal wheels.  But the loco consist still needs to be shorter than the reversing section itself.

I have a number of Walthers passenger cars that are set up for lighting, but I run them without any lighting attachments.  But the metal pickup plate for the lighting is enough to affect even the PSX-AR if the entire train is longer than the reversing section.

Prudence dictates that the reversing section be long enough to accommodate the longest train using the reversing section.  The OP indicates that this is the case on his layout.

Rich

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Posted by Anonymous on Thursday, July 24, 2014 9:26 AM

trafficdesign
 
BMMECNYC

I believe Rich solved your problem 6months ago

 

 

 

I thought so too... but it doesn't work. The pic you posted wouldn't work as the distance between the crossovers is only a couple of feet. So we came up with a new idea and that is what I am having trouble with.

 

 

Read the pg 9 of the PSX-AR instructions for having a reversing section shorter than the train length. 

here:

http://dccspecialties.com/products/pdf/man_psxar.pdf

EDIT: And even that note says that extra gaps may be required.  I am a firm believer that the train length reversing section is a holdover from the days of manual reversing loops, and aren't required anymore, just recommened.  I could see that the arguement could be made that lighted passenger cars may cause the reversing section to short or cycle excessively, but that has not been my experience.

Someone may correct me if im wrong but that should work as well.

I still contend the the reversing section does not have to be longer than the train.  I have run 30ft long trains through  a 3ft reversing section (metal wheels) without issue.  (I do not know which reverser is installed on that particular club module.

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Posted by trafficdesign on Thursday, July 24, 2014 9:23 AM

richhotrain
  

But, what troubles me is the multiple clicks that the OP is hearing.  That indicates that the AR-1 is constantly sensing mismatched polarities.  I still wonder if the OP has any solid state components (e.g., a PSX circuit breaker) elsewhere on the layout that is overwhelming the mechanical relay on the AR-1.

Rich 

Nothing else except a Zephyr extra and a UT4 throttle.

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Posted by richhotrain on Thursday, July 24, 2014 9:18 AM

zstripe

 

what about the metal wheel sets on the cars after the polarity has been set....would that not trip the AR again, appearing to work intermittently, when the wheels bridge the gaps? especially if they are right across from one another, the gaps should always be staggered, I was taught.

 

 

Once the AR-1 flips the polarities inside the reversing section to match the polarities of the adjacent track outside the reversing section, additional wheelsets crossing the gaps should have no effect on the AR-1 as long as the polarities inside and outside match.

I never intentionally stagger gaps on reversing sections, but I suppose that they might be staggered anyhow because I do not consciously attempt to align them perfectly.  Digitrax is silent on the matter, but the instruction sheet for the PSX-AR suggests a 1/8" stagger, stating that perfectly aligned gaps may reduce the current needed for the PSX-AR to reverse properly.  Dunno, maybe staggering gaps would make a difference.  

But, what troubles me is the multiple clicks that the OP is hearing.  That indicates that the AR-1 is constantly sensing mismatched polarities.  I still wonder if the OP has any solid state components (e.g., a PSX circuit breaker) elsewhere on the layout that is overwhelming the mechanical relay on the AR-1.

Rich

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Posted by trafficdesign on Thursday, July 24, 2014 8:58 AM

zstripe

But what about the metal wheel sets on the cars after the polarity has been set....would that not trip the AR again, appearing to work intermittently, when the wheels bridge the gaps? especially if they are right across from one another, the gaps should always be staggered, I was taught.

Take Care! Big Smile

Frank

Good idea to stagger the gaps! I wonder if that might be something to test and see if it makes a difference. AR1 test of reverse loop will be completed this AM and we will have another piece of the puzzle...

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Posted by zstripe on Thursday, July 24, 2014 8:40 AM

Rich,

I know about this part:


 

You want the wheels to bridge the gaps so that the auto-reverse unit senses a short and flips the polarity of the rails to correct the situation.


 

But what about the metal wheel sets on the cars after the polarity has been set....would that not trip the AR again, appearing to work intermittently, when the wheels bridge the gaps? especially if they are right across from one another, the gaps should always be staggered, I was taught.

Take Care! Big Smile

Frank

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