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100% trouble free reverse loop please!

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  • Member since
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  • From: Colorful Colorado
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Posted by Texas Zepher on Friday, January 30, 2009 8:05 PM

nyflyer
Texas Zepher
I assume you will also want the turnout to automatically switch to the track of an approaching train.  Do do this will require some directional track occupancy detection.  The detector would sense a train approaching and automatically through the turnout to align to the approaching train.
Would the powershield X be all I would need here or would I still need the block detector product as well

I just checked the on-line manual and as the others have said, the PSX-AR has occupancy built in.

The only issue that I can see is where the gaps for the reverse loop are.  If they are too close to the ends of the turnout, and a slow motion machine (like a tortoise) is used, and if the train is going fast, the train might get to the points before the turnout has a chance to move them. 

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Posted by Mark R. on Friday, January 30, 2009 7:42 PM

selector

The method described above is inexpensive, comparatively, and works very well....if...you remember to throw the DPDT when the time comes.  Not to say a couple thousand people currently running layouts aren't doing that quite well.  But, a person forgets.

.... but this method does NOT require you to throw the DPDT - it throws WITH the turnout ! You MUST throw the turnout to either enter or exit the loop, the DPDT contacts are automatically thrown WITH the turnout. If you forget to throw the turnout when exiting, polarity match isn't going to be your biggest concern .... if anything, the dead short will stop your train before running through a mis-aligned turnout - an auto-reverser won't do that !  ;-)

Mark.  

¡ uʍop ǝpısdn sı ǝɹnʇɐuƃıs ʎɯ 'dlǝɥ

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Posted by selector on Friday, January 30, 2009 12:55 PM

The method described above is inexpensive, comparatively, and works very well....if...you remember to throw the DPDT when the time comes.  Not to say a couple thousand people currently running layouts aren't doing that quite well.  But, a person forgets.

The PSX-AR, while more than a good RTR engine (not upper crust ones, more like BB), doesn't forget.  If you wire it up well, with slightly staggered gaps on each end of the desired length of reversing section of track, it is fire and forget.  You have fun with the trains, and all you must do is line the route if it involves the use of the reversing section.  The PSX-AR does all the rest for you silently and efficiently.

Ya pays for convenience.  But convenient it surely is. Cool

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Posted by Mark R. on Friday, January 30, 2009 11:49 AM

I took an even simpler approach that is 100% fool-proof. I utilized a DPDT relay that is turned on / off through a set of contacts on the reverse loop turnout. The DPDT relay is wired in typical reverse loop fashion. This way, which-ever route the turnout is thrown for, the polarity for the reverse loop is automatically lined for that direction. The turnout must be thrown to leave the loop, so the polarity is automatically reversed to leave the loop.

Mark. 

 

¡ uʍop ǝpısdn sı ǝɹnʇɐuƃıs ʎɯ 'dlǝɥ

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Posted by DigitalGriffin on Friday, January 30, 2009 9:52 AM

MisterBeasley
My reading of the linked instructions indicates that you can still throw the switch manually, either through your DCC system or with the use of pushbuttons. 

 

Sorry, I should have clarified...You can't directly connect the switch machine to a control panel any more.  You can still throw the switch, you just need to go through the PSX-AR to do it.

Sorry about the confusion.

 

Don - Specializing in layout DC->DCC conversions

Modeling C&O transition era and steel industries There's Nothing Like Big Steam!

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Posted by DigitalGriffin on Friday, January 30, 2009 9:50 AM

nyflyer
Would the powershield X be all I would need here or would I still need the block detector product as well

 

You only need the PSX-AR model.

 

Don - Specializing in layout DC->DCC conversions

Modeling C&O transition era and steel industries There's Nothing Like Big Steam!

  • Member since
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Posted by nyflyer on Friday, January 30, 2009 8:10 AM

Texas Zepher

I assume you will also want the turnout to automatically switch to the track of an approaching train.  Do do this will require some directional track occupancy detection.  The detector would sense a train approaching and automatically through the turnout to align to the approaching train.  Or if you don't mind always going through the reversing loop in the same direction it could be simply spring loaded. 

Would the powershield X be all I would need here or would I still need the block detector product as well
  • Member since
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Posted by Trainman Sam on Thursday, January 29, 2009 11:09 PM

Texas Zepher
I assume you will also want the turnout to automatically switch to the track of an approaching train.  Do do this will require some directional track occupancy detection.  The detector would sense a train approaching and automatically through the turnout to align to the approaching train.  Or if you don't mind always going through the reversing loop in the same direction it could be simply spring loaded. 

Just to clarify on this, you still have to double gap the rails of the loop from the switch.  Otherwise, depending what type of spring switch is used, the point will cause a short in the system.

As a side note to the spring switch itself:  Many prototype RR's have discontinued the use of spring switches due to heavy maintenance costs (i.e.: the point being "slammed" back into the stock rail so many times causes it to come out of gauge, or damage the points eventually leading to a "picked" switch in which the wheels ride up and over the points leading to all types of problems...

I'm not sure if this applies to the model just like the prototype...  If anyone can prove or dis-prove, I would definitely like the info, as I am in the process of designing a layout that I will undoubtedly want to utilize a reverse loop!

Sam

Sam

 May He bless you, guide you, and keep you safe on your journey through life!

 I Model the New Hope & Ivyland RR (Bucks County, PA)

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Posted by Texas Zepher on Thursday, January 29, 2009 6:58 PM

nyflyer
I am going to be laying the track for  a reverse loop on my layout in the next few weeks.  This is a major section of my railroad and will be seeing continuous train traffic.  I have been reading articals, posts and technical data on this subject, and the only thing i'm sure of is I have a headache.

The short answer is, no.  There are always things that come up.  You can make some pretty rock solid wiring & trackwork which will limit (at least for a time) the issues to the performance of the locos & rolling stock.    I don't understand, if you did all that research don't you already know this. Confused

Even with rock solid trackwork, is the room where the layout is climate controlled?  If not constantly changing temperatures and/or humidity can create problems over time. 

So please is there a way to put a switch and reverse loop in without ever worring about shorts derailments or other problems?

If you can find a way to lay track, reversing loop or not, without EVER worrying (100% trouble free) about shorts derailments and other problems, then you could write a paper / procedure on it and become model railroad famous.

So is there some combination of switch insulated or non insulated, switch machine, reverse loop / circute breaker combo (ie. powershield, Hare or Rabbit) setup that is trouble free?

There are many many different combinations that will accomplish almost what you are asking for.    I would select a DCC automatic reverser that is 100% electronic and doesn't use mechanical relays.  That means it will be more expensive.

You have said nothing about how long the reversing loop is.  Is it long enough to contain the longest train that will ever run on the layout?  If that is not true, then that could cause more issues than any wiring problem.

I assume you will also want the turnout to automatically switch to the track of an approaching train.  Do do this will require some directional track occupancy detection.  The detector would sense a train approaching and automatically through the turnout to align to the approaching train.  Or if you don't mind always going through the reversing loop in the same direction it could be simply spring loaded. 

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Posted by MisterBeasley on Thursday, January 29, 2009 6:43 PM

My reading of the linked instructions indicates that you can still throw the switch manually, either through your DCC system or with the use of pushbuttons.  It may be that you need to connect the buttons differently, but it can still be done.

I have an older Tony's reverser unit, and it's been running fine for years.  It's a good product.

 

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

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Posted by DigitalGriffin on Thursday, January 29, 2009 5:34 PM

1.  Use a DCC friendly turnout

2.  Leave the track double gapped on both routes on the backside of the turnout.  (In other words, you don't want them conducting power to the reverse loop)

3.  Get an autoreverser.  Tony's PSX-AR is a combination breaker/autoreverser, and can handle auto throwing Tortoises, or dual coil switch machines.  It's considered one of the best, but also the priciest.  Works with any DCC system and has support for feedback.  However once you hook your switch machine to the PSX-AR, you can't throw it manually yourself.  You have to let the PSX-AR handle it.

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

4.  Hook the reverse loop to the autoreverser terminals.  When the autoreverser detects a short, it will automatically reverse the current.

5.  If you want to autothrow the switch machine, be sure to have enough space between the reverse loop and the switch machine points for the switch machine to respond.  (Especially true with slow motion tortoises!)

It really is quite simple once you do one.

Don - Specializing in layout DC->DCC conversions

Modeling C&O transition era and steel industries There's Nothing Like Big Steam!

  • Member since
    January 2004
  • 49 posts
100% trouble free reverse loop please!
Posted by nyflyer on Thursday, January 29, 2009 5:14 PM

I am going to be laying the track for  a reverse loop on my layout in the next few weeks.  This is a major section of my railroad and will be seeing continuous train traffic.  I have been reading articals, posts and technical data on this subject, and the only thing i'm sure of is I have a headache.

So please is there a way to put a switch and reverse loop in without ever worring about shorts derailments or other problems?

I have a DCC system and do not mind putting the extra money into components to keep everthing running smoothly.

So is there some combination of switch insulated or non insulated, switch machine, reverse loop / circute breaker combo (ie. powershield, Hare or Rabbit) setup that is trouble free?  I don't mind putting the time and money in now to get it right.  I JUST WANT TO RUN MY TRAINS! 

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