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Is an autoreverser needed.

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  • Member since
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  • From: Christiana, TN
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Posted by CSX Robert on Friday, March 21, 2014 8:57 PM

Moses45

Maxman.Yes, I have 2 on the reversing section..

You are only supposed to have one reverser per reversing section.

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Posted by zstripe on Friday, March 21, 2014 9:19 PM

Moses45,

Thanks for posting that. We all make mistakes and it takes a real man to admit it. Yes

True story, from Forums past: I guy had a great running layout so he thought. added two stub ended spurs and his layout kept shorting out, everyone tried to help him. It took three pages later and a lot of teeth pulling to find out he added a all metal track bumper to the end of one of his spurs, instant short, without first cutting a gap in at least one rail. Big Smile

Take Care!

Frank

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Posted by richhotrain on Saturday, March 22, 2014 4:16 AM

rrinker

Should be able to get away with just gapping both ends of the track that runs through the bottom middle. No other gaps. Unless that stretch of track is not long enough to contain a complete train.

Both rails gapped on the left where that center track diverges, and the second set of gaps in that same track on the right about where the words "double gap here" are to label the circle. The gaps in that crossover would be unecessary.

                         --Randy

 

YES.  That is exactly the solution that I had proposed to the OP, including the location of the gaps, and the exact wiring for a single AR-1.  That solution would eliminate the need for gaps in the center of the crossover and minimize the possibility of two trains simultaneously entering and exiting the reversing section.  There is no reason to create a larger reversing section.

Rich

Alton Junction

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Posted by richhotrain on Saturday, March 22, 2014 4:18 AM

CSX Robert

 

 
Moses45

Maxman.Yes, I have 2 on the reversing section..

 

 

You are only supposed to have one reverser per reversing section.

 

I wish that the new forum software included an emoticon of someone shaking his head.   Bang Head

Rich

Alton Junction

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Posted by richhotrain on Saturday, March 22, 2014 4:24 AM

Moses45

I have been reading up on this at a couple of sites, Here is one idea I read that would help a novice understand; One guy took a caboose and marked one side of it red and then pushed it over his layout to see what was happening with where his wiring was. Makes sense to me.

 

That would not be necessary, and I doubt that it would be helpful to someone who does not understand the basic principles of reverse polarity.

The key to success is to draw a two-rail color-coded track diagram.  In that way, the problem becomes obvious before ever laying track or wiring the layout.

Using red and black as an example, if you color one rail red and one rail black, then red rail should always connect to red rail, and black rail should always connect to black rail.  Assuming that you always wire your feeders correctly, when red meets black and black meets red, you have reverse polarity and an isolated section of track needs to gapped to resolve the issue.

Rich

Alton Junction

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Posted by richhotrain on Saturday, March 22, 2014 5:51 AM

One of the peculiarities of a reverse loop is that there is typically more than one way to wire the track, depending upon how and where you place the feeders as you enter and exit the reversing section.  As a result, the point of reverse polarity may occur at one end of the reversing section or at the other end of the reversing section.  It all depends upon where you choose to place feeders as you begin to wire the reversing section.  So, designing and wiring a reverse loop can be as much of an art as it is a science.  The objective should be to wire the reverse loop with as few gaps as necessary.  Too often, you see reverse loops with gaps all over the place when that is really not necessary.  This particular layout could have been designed with two sets of gaps.

Rich

Alton Junction

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Posted by mobilman44 on Saturday, March 22, 2014 6:20 AM

Hi,

It is a very simple process to determine if one has a reverse loop, and yet there are folks that are unaware of their existance on the layouts that they build.

As I learned as a young teenage newbie entering the DC/HO world, if you can roll a car (or your finger) over your layout and end up with it going in the opposite direction on the same trackage, you have a reverse loop.

If one can build a layout, one should be able to do this.

ENJOY  !

 

Mobilman44

 

Living in southeast Texas, formerly modeling the "postwar" Santa Fe and Illinois Central 

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Posted by rrinker on Saturday, March 22, 2014 10:04 AM

 You know what's good for a car like that? Pick up some old cheap train set car for a buck or so at a train show, and practice your painting on one side of it.

                   --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 Moses45 on Saturday, March 22, 2014 12:00 PM

Randy, You gave me a good laugh. It is not that I dont understand polarity. I just have a hard time seeing where it occurs. The guy that put a piece of red tape on an old caboose on the same side as his red wire (track A) and then pushed it around his layout would soon discover his reversing section. The minute he sees the red side of the caboose over the black wire (track B) he would see the problem.

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Posted by richhotrain on Saturday, March 22, 2014 1:28 PM

Moses45

Randy, You gave me a good laugh. It is not that I dont understand polarity. I just have a hard time seeing where it occurs. The guy that put a piece of red tape on an old caboose on the same side as his red wire (track A) and then pushed it around his layout would soon discover his reversing section. The minute he sees the red side of the caboose over the black wire (track B) he would see the problem.

 

Would he???

 

Alton Junction

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Posted by rrinker on Saturday, March 22, 2014 2:28 PM

 Hmm, I wasn;t trying to be funny, it was a serious suggestion, take a cheap car and paint one side of it something obviously different, then roll it around the layout over all possible routes and if the painted side ever shows up facing both sides of the same section of track without physically picking the car up, you have a reverse loop.

                --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 Moses45 on Saturday, March 22, 2014 3:25 PM

Seems like a good idea. It would save pushing anything around.

 

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Posted by richhotrain on Saturday, March 22, 2014 4:46 PM

rrinker

 Hmm, I wasn;t trying to be funny, it was a serious suggestion, take a cheap car and paint one side of it something obviously different, then roll it around the layout over all possible routes and if the painted side ever shows up facing both sides of the same section of track without physically picking the car up, you have a reverse loop.

                --Randy

 

Yeah, but that is only one way to find out.  On the OP's layout, when the car crosses that crossover, it will short the first time that it crosses either way.  Pushing a painted car around a layout is not a be all and end all for discovering reverse polarity.

Rich

Alton Junction

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Posted by rrinker on Saturday, March 22, 2014 8:47 PM

 No it won't - notice I said cheap train set car - they never have metal wheels.

Actually, the idea would be to do it BEFORE hooking up the power, or at the very least before turning it on.

It's all overkill anyway - all you REALLY have to do is trace your finger over an ACCURATE track diagram. If you find that you are moving left to right AND right to left over the same section, you have a reverse loop.

                    --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 Saturday, March 22, 2014 9:47 PM

rrinker

 No it won't - notice I said cheap train set car - they never have metal wheels.

 

Ooh, low blow !  Laugh

Rich

Alton Junction

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Posted by richhotrain on Saturday, March 22, 2014 9:52 PM

rrinker

It's all overkill anyway - all you REALLY have to do is trace your finger over an ACCURATE track diagram. If you find that you are moving left to right AND right to left over the same section, you have a reverse loop.

               

 

Yes it is overkill.

If you cannot visualize it by just looking at it, then draw a two-rail, color coded track diagram.

And, of course, not all reversing sections are reverse loops.  Or, at least, they don't all look like loops.

But, the OP is not alone.  There are a lot of posts on this forum where guys struggle with the issue of reverse polarity.

Rich

Alton Junction

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Posted by rrinker on Saturday, March 22, 2014 11:28 PM

 The key always is, can you move over the rails in a way that has you going both ways on one piece of track without lifting your finger - covers loops, wyes, and turntables.

 Going back to the earliest days of MR, there have been articles on this, the "two rail bugaboo" (actual title of one article, I believe). Every few years it warrants coverage in an article or column. Part of the problem is once Atlas came out with their electricla components and everyone starting out just followed the diagrams in their plan books, the whole mechanism behind the scenes was hidden. There's a lot of 'magic' going on inside that Controller, but you can;t see how it's all wired, so it remains a mystery.

                   --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 Sunday, March 23, 2014 5:15 AM

For those who cannot visualize a reverse polarity situation and, for whatever reason do not want to take the time to draw a two-rail, color-coded track diagram, I think that a better idea than a painted car or your fingers would be to use automotive pinstripe tape.

You can buy rolls of automotive pinstripe tape for less than $2 per roll, and it comes in all kinds of colors including red and black and in various widths as narrow as 1/16".

Cut short lengths of pinstripe tape and place it outside the rails on the ties, red on one side, black on the other side.

Reverse polarity never occurs on a straight section of track unless you cross wire the feeders.  

There is always a turnout, regular, curved, wye, 3-way, crossover, double crossover, involved in a reverse polarity situation.

When red and black are joined together, bingo, reverse polarity.

Rich

Alton Junction

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Posted by zstripe on Sunday, March 23, 2014 6:36 AM

Quote:

RECOMMENDATION:  Build a Short Detecting Beeper BEFORE You Start ANY DCC Track Wiring!

It's no accident that this recommendation is the first in the track wiring section. If you wait until you find out you have shorts, it's too late. Don't wait until you wish you had made one of these. Do it now. It only takes a few minutes and a few dollars to put together.

Simple Buzzer

Buy a 273-059 buzzer from Radio Shack and a 270-325 9V battery clip. And, of course, a 9V battery. Then attach this instead of a booster to your track while doing all wiring. Any wiring error that you make that results in a short will cause an immediate beeeeeep. This is before you've soldered the wire or hooked up twenty feeders only to find nothing works! Use this thing religiously.

If you have several boosters, you will need to move the beeper to each booster district as you wire. Alternately, if you have a team wiring several districts at once, temporarily jumper the main booster feeders together so only one beeper is needed.

You could also mount the circuit in a bobber caboose or clip it to the track with alligator clips. Be sure the boosters are not connected to the track.  I cannot emphasize this enough.  The booster will appear as a short to the beeper.  Nothing but the beeper should be attached to the track.

You can use an ohmmeter, but you will get squirelly results.  So don't do this unless you have a very good understanding of exactly how an ohmmeter works.


 

Frank

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Posted by mobilman44 on Monday, March 24, 2014 6:01 AM

Good Idea Frank!

I used a similar tester - the kind with the light as opposed to the buzzer.  Either will work just fine.   Of course the thing is, one needs to test periodically as they are wiring/laying track so as to find a problem early on.

 

ENJOY  !

 

Mobilman44

 

Living in southeast Texas, formerly modeling the "postwar" Santa Fe and Illinois Central 

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Posted by richhotrain on Monday, March 24, 2014 6:04 AM

If you draw a two-rail, color coded track diagram and place those feeders correctly, you won't need any buzzers or lights or painted cars to find points of reverse polarity.  All of these gimmicks are a waste of time in my view.

Rich

Alton Junction

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Posted by rrinker on Monday, March 24, 2014 6:26 AM

 And yet people manage to hook up feeders backwards - we've had that here a few times. The buzzer would find that.

Two things I made early on, a decoder tester and a buzzer box. Both ended up in the junk drawer in short order, never to be used.

I use two different color wires for feeders, put in place as the track is laid, and which matches the colors of the wires I use for bus wire, so red to red, white to white, and it's always right.

          --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 MisterBeasley on Monday, March 24, 2014 6:40 AM

Go all the way.  Don't just get a buzzer, get a meter.  My old meter has a buzzer in it, and it will do all sorts of useful other things that will help you in this hobby.  You don't need an expensive professional model.  The low-cost ones from Harbor Freight will do fine.

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

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Posted by Mark R. on Monday, March 24, 2014 12:07 PM

Never had a buzzer, or even used one - but I can see where they would be a useful tool for people who have trouble visualizing things like this. 

When laying track or soldering feeders, always have the buzzer connected. So if you are on the other side of the benchwork or even under it, you would immediately hear the buzzer should you attempt to connect a piece of problematic track or solder a feeder wire to the wrong side. A light or a meter would have to be purposely looked at for every move you make.

Mark.

¡ uʍop ǝpısdn sı ǝɹnʇɐuƃıs ʎɯ 'dlǝɥ

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Posted by mobilman44 on Tuesday, March 25, 2014 6:15 AM

Good idea Mark!

Some folks doing wiring need more help than others.  And I have to remember that we all tend to have different specialties and different levels of expertise in the various aspects of building a layout. 

 

ENJOY  !

 

Mobilman44

 

Living in southeast Texas, formerly modeling the "postwar" Santa Fe and Illinois Central 

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Posted by zstripe on Wednesday, March 26, 2014 3:28 PM

Marks reply, is exactly why the buzzer is more helpful. You leave it connected to your track work, when you lay your track, even before feeders and buss. Also in DC use. Once you have enough experience, it probably would wind up in the junk drawer. Continuity tester, without viewing it or holding it.

Frank

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Posted by richhotrain on Wednesday, March 26, 2014 5:16 PM

Leave the buzzer at Radio Shack and learn how to spot reverse polarity before a short occurs in the first place.

Rich

Alton Junction

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