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Need help with AR1 & reversing loop

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  • Member since
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  • From: Bedford, MA, USA
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Posted by MisterBeasley on Wednesday, March 4, 2009 11:45 AM

From the symptoms, I think something is wired incorrectly.  How many feeders do you have going to the loop?  Is it possible that you've got one set of feeders from the loop connected up to the main, instead?  Or maybe one set of feeders from the main going to the AR1?

Disconnect the loop wires from the AR1.  Put an engine in the loop.  If it runs, you have a problem right there.  If it doesn't run, connect one of the wires and try the loco again.  Then disconnect that one, and connect the other one.  If the loco runs in either of those configurations, you've mis-wired something.

Check your gaps, too.  If you used plastic rail joiners, but the rail ends are still touching, there's no gap at all.

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

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Posted by HHPATH56 on Wednesday, March 4, 2009 10:36 AM

Hi Dave,

If it is a stub ended yard,  it is not part of a reverse loop, so you do not need to use an AR1  The AR1 just goes across the insulated gap in the cross-over, and of course, the original gap at the top of your diagram, for the reverse loop.  Someone on the Forums mentioned that the AR1's have been replaced with an updated version. If you look at my track plan, you will see that the 7 track pass-through yard, (on the center peninsula), is part of a complex reverse loop. So, every one of the gaps on the seven tracks must have a reverse loop module across it. Besides this, I have 5 other reverse loops, 3 wyes, and a round table, or a total of 4 Digitrax PM42's, (or more!)  They are great, since they include circuit breakers.  Does the fact that you are using a Digitrax Super Chief mean that you have quite a large layout? Most of the members of my model railroad club have the Digitrax Zephyr, which is quite adequate for a smaller layout.  With over 100 turnouts, I decided to have each set of 24+ switches controlled by the 4 operators, who can visually see which switches to throw. I still may use tiny momentary center-off toggle switches on the 4 track diagrams, but the numbered touch probes are easier to wire, and are faster than using Digitrax switch controls.     Bob Hahn

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  • From: Maine
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Posted by mainetrains on Wednesday, March 4, 2009 9:27 AM

Bob it's a stub end yard. So where would I put the other AR1?

Dave Banged Head

'there's something happening here, what it is ain't exactly clear' Modeling the Hard Knox Valley Railroad in HO scale http://photos.hardknoxvalley.com/

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Posted by HHPATH56 on Tuesday, March 3, 2009 3:51 PM

 Hi Dave,    Yes, you do need 2 AR1s (or upgraded version).  You say that the other rails lead to a yard. Is that a stub ended yard, or a pass through yard, with the rails shown attached to the two ends of the yard?   I have a 7 track pass-through yard, which is part of a reverse loop.  So, I have to use 2 Digitrax PM42s, which can be used for Power Management of 4 sub-districts, or to control 4 reverse loops (with circuit breakers included). At $80+ for 4 reverse loops and circuit breakers, it is cheaper than 4 AR1's.  One can mix and match the functions. I have a 24'x24' around the room HO layout,(divided into 4 Power Districts) Each district has control of 24 electric switches and a couple of manual switches. With my "spaghetti" 240 yds of track,5 reverse loops and 3 wyes, I will require a DCC expert to figure out how to wire the Digitrax Superchief HO layout.  I have all the track isolated and laid, (with each flextrack section connected to the bus wires), switches are wired to common grounded touch probe activators on 4 control boards. All of the scenery is nearly finished, yet I have never run any loco on the 18 different routes around the entire layout. I am installing "tail light" short sensors. Hopefully, I won't have too much trouble ????       Bob Hahn   e-mail ROBTAHahn@Earthlink.net   Click on "track diagram" to enlarge it. Then, click on photos  to the right, to see most of my layout. Those photos enlarge, also.


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Posted by mainetrains on Tuesday, March 3, 2009 12:40 PM

I'll try to answer your questions - I have a digitrax super chief DCC system so it should be compatible with the AR1. The rest of the layout - where the open ended tracks lead to - is basically a yard area so should not have an affect on the reversing loop. At least I don't think so. I have a question for Bob - do you think I need to AR1's?

Thanks,

Dave Banged Head

'there's something happening here, what it is ain't exactly clear' Modeling the Hard Knox Valley Railroad in HO scale http://photos.hardknoxvalley.com/

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Posted by Vail and Southwestern RR on Tuesday, March 3, 2009 12:32 PM

I have not looked at this long enough to be sure, and it would be nice to see the rest of it, but....

If the section is long enough, I think you could just gap the arc between the upper and lower switches, and control it with the reverser.  That way it serves as the reversing section whether you go around the loop or through the crossover.

Jeff But it's a dry heat!

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Posted by Mark R. on Tuesday, March 3, 2009 12:19 PM

I think your gap location should be ok. There's a possibility that the unit is incompatable with your system !  Does that unit have an adjustment potentimeter on the board (I'm not familiar with it).

Reversing modules rely on either a preset or adjustable trip current to throw the reversing relay on the board. If the trip current on the reversing module is rated higher than your DCC system, your DCC system will shut down before the reverser can trip !  If the reversing module has an adjustment on the board, try lowing the setting until it will cross the gaps without throwing the breaker on your DCC system first.

If the module doesn't have an adjustment on it, you may end up having to get one that does in order for it to function with your DCC system.

Mark. 

¡ uʍop ǝpısdn sı ǝɹnʇɐuƃıs ʎɯ 'dlǝɥ

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Posted by HHPATH56 on Tuesday, March 3, 2009 12:17 PM

             Hi Dave,                                                                                                                                 Your problem is that you have a reverse loop feeding into a cross-over.   Suppose that you just had a reverse loop with no bottom gap or cross over turnout. Make the top wire a "+" .  The module ,(across the top gap), changes the top wire to "-" , which will match the "-" when it leaves the loop.  Now move the bottom gap to the center of  the cross-over. Before the gap, the rail on the top will be "-", and the bottom rail will be "+". If you install another module across the gap, the top rail will become "+" and the bottom rail will become "-".  This will then match the + and - beyond the switch.   Any cross-over requires a gap and a reverse loop module,across it to prevent a short.  You might wonder what happens with a double-slip switch. The wiring of a double-slip switch takes care of the cross-over problem, but only with DCC will the loco keep forward motion.  Are you using DCC?  Reverse loops and crossovers,(with gaps and reverse loop modules), are really meant for DCC.     Bob Hahn. 

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Posted by bwchaney on Tuesday, March 3, 2009 11:45 AM

I believe your problem is the bottom gap shown in your drawling.  I think you need to gap next to it also where your two switches cross over.  Do that and I think you will be okay.  bwchaney

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Posted by MisterBeasley on Tuesday, March 3, 2009 9:50 AM

There's nothing obvious from the diagram, but it's not complete enough to track stuff down.  I hate to do this, but can you post a more complete picture?

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

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Need help with AR1 & reversing loop
Posted by mainetrains on Tuesday, March 3, 2009 9:28 AM

Need some help/advice - I've been having trouble getting an AR1 to work. This is a rough drawing of the reversing loop on my layout. Not to scale by any means but it should give you the general idea. I have wired the AR1 correctly according to the directions that came with it. Two wires out to the main power bus - then a bus for the AR1 with rail feeders. One weird thing - the train only shorts going out of the loop if it enters at the gap to the bottom. If I reverse the wires for the AR1 it shorts leaving at the bottom gap. In other words, it will enter the loop but not exit.
Any advice? Maybe I'm not seeing something here.

Thanks,

Dave Banged Head

'there's something happening here, what it is ain't exactly clear' Modeling the Hard Knox Valley Railroad in HO scale http://photos.hardknoxvalley.com/

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