Reversing Loops and DCC

[HAZMAT9]

I'm at the point of finishing up my track work. I have a reversing loop that I'm putting in and this is the last section that I need to install and I'm done. I'm using the loop to basically turnaround box and passenger cars and I was able to fit it in with 18" curves. Question is, based on what I've seen, do I need to buy the booster set up in order to wire the loop up for DCC. I plan on using a MRC Prodigy Advance system....or does Prodigy account for this (still need to purchase the system). Lastly, in wiring up the loop, do I need to add any insulated railjoiners or anything special..... I would like to run the set up on DC to test the track out. Thanks!

[cacole]

You need insulated rail joiners at both ends of the reversing loop track, and either a DPDT toggle switch or an automatic reversing module to control the polarity of the loop.

Check Tony's Train Exchange, Loy's Toys, or Litchfield Station for information and prices of auto-reverse modules for DCC. Several companies make these -- MRC, Digitrax, and NCE to name just a few.

Something not mentioned by any of the auto-reverse module manufacturers is that they work best if your insulated rail joiners are staggered 1/8 to 1/4 inch on both ends. Tony's site mentions this in one of his "Tony's Tips," but no one else does.

http://www.tonystrains.com
http://www.loystoys.com
http://www.litchfieldstation.com

[Anonymous]

I'd go with an Auto Reverse Module. I don't believe the MRC Prodgiy command / booster station has an auto reverse, but check it out first before getting a reverse module.

[HAZMAT9]

Great! This is easier than I originally thought. On the loop, do I need to put two insulating rail joiners from the switch into the loop...or it doesn't matter (as long as you have one rail joiner to break the circuit)? I just need to know this in order to nail the track down now so I can run tests on the rest of the layout....while ordering the reverser. Thanks!!

[Texas Zepher]

QUOTE: Originally posted by cacole
Something not mentioned by any of the auto-reverse module manufacturers is that they work best if your insulated rail joiners are staggered 1/8 to 1/2 inch on both ends.

I just looked through the Tony's Tips and cannot find where that is mentioned. Why would this be true? A short circuit is a short circuit whether or not it happens on one rail or both simultaniously. The only thing I can think of is perhaps it "pits" the rail in two different places depending on direction rather than always in the same place.

Edit - after pcarrell's post I found the reference (well a reference. it is the only occurance of the word "stag" or "staggered" there) . It does not say generically that auto-reverse modules work best if joiners are staggered... It is including auto reversing power boosters in the discussion and says, notice the quotes:
"Be sure to follow the booster manufacturer's instructions. For Digitrax boosters, the gaps should be directly across from each other. The Loy's Toys' ARSC prefers to have the gaps staggered a bit. If you are controlling a reverse loop or wye with a relay, exactly where the gap is doesn't matter exactly where you put the gaps. For your own troubleshooting sanity, put them very close or across from each other."

Then the long description of why Loy's Toys wants them staggered is given here: http://www.loystoys.com/info/reverse-section-control.html#ARSC

[HAZMAT9]

Forgot to mention in my dilemma, my reversing loop starts off at a #4 switch and loops around into a leg of a wye switch. The wye is used to branch off the mainline and the other the loop. So in using a wye in a reversing loop, can I still use the MRC reversing module (I'm assuming that I just need to insulate the wye branch going to the reversing loop)?

[pcarrell]

Look about 3/4's of the way down this page and you'll find out all about reverse loops, wye's, and DCC;

http://www.wiringfordcc.com/track_2.htm

[Anonymous]

QUOTE: Originally posted by HAZMAT9

Forgot to mention in my dilemma, my reversing loop starts off at a #4 switch and loops around into a leg of a wye switch. The wye is used to branch off the mainline and the other the loop. So in using a wye in a reversing loop, can I still use the MRC reversing module (I'm assuming that I just need to insulate the wye branch going to the reversing loop)?

Both rails in the loop need to be insulated. Remember, whenever a rail turns back to the oposite rail, it needs to be insulated. Click on the words Auto Reverse Module and see the wire diagram. Follow one rail and you see the rail becomes the opposite rail. Therfore both rails need to be insulated.

I'm not sure I understand you correctly about the wye. Does the wye change direction of the train as in wyeTrackage or are you saying you are using a wye turnout, rather than a regular turnout, to route the train down another track? In otherwords, you mean that the wye turnout is inside the loop and one route continues the loop and the other route goes.... where?
If the latter is true, and if the wye turnout is past the insulated gaps then no other gaps past the wye turnout is needed. If the wye turnout is before the gaps, then you need to insulate the branch IF it is connected to the main line in any way.

[HAZMAT9]

Here's a link to sketch of what I'm talking about (below). The wye acts like a switch with one branch used for the mainline and the other branch is used in the loop. It's kinda like a turnaround more than an actual reversing loop. Thanks

http://www.geocities.com/hazmat9us/WYE.html

[Anonymous]

Ok I get it now. Following the track counter clockwise and entering the loop from the left side, the gaps need to be placed in the loop past the left hand turnout and before the wye turnout on the loopside.

[HAZMAT9]

Fantasitc! Many thanks Gary...I'm assuming that I can go ahead and use an MRC Reverser Module to power and reverse the current in the loop?

[Anonymous]

Go for it Steve.

[Anonymous]

Timely thread. I just wired up an AR1 on my reverse loop about 15 minutes ago! It worked. I simply double gapped each end of the reverse section, then I ran track feeds to the two terminals on the AR1. Then I ran two power feeds to the other two terminals on the AR1 and voila' - auto reversing is successful!

If you need to see what I went through to figure out how to accompli***his, it wasn't easy - check out my thread in the DCC Forum on the Atlas Forums, here's the link:

http://forum.atlasrr.com/forum/topic.asp?TOPIC_ID=26532&whichpage=1

Hope this is helpful to you!

[claycts]

Running an AR1 and A RSRev, USE the RSREV Easier to use and works better.
My $.02

[Anonymous]

Either the loco runs through the section or not. It runs flawlessly through my section.

How could one be "easier" to use than the other? Only 4 leads to the Digitrax AR1, how much easier can it be than that?

[R. Vollmar]

If you don't want to purchase an auto-reversing unit, you can go with a DPDT reversing switch wired in the same manner as if you were using straight DC and connected to the loop. In DCC you can reverse polarity while the locomotive is in the loop and it will not effect the operation as it would with straight DC. This method is also useful for wiring crossovers between two directions on a main line in a dog bone scematic

[FCnota]

I have to put my vote in for Tonys autoreverser. Put it in, simple wiring and works flawlessly. Second best investment after the dcc system!

[Anonymous]

Lenz has one reverse loop,that you can connecting with DCC power.It`s name:LK 100
I have one Lenz SET100 with V 3.5 and can also driving doubleheaded BLI locomotiv with sounds and doing reverslooping with LK100 without loosing sounds too!
I`m not so sure, if you can using Lenz LK100 with other DCC components!?

agge [8D]

[Anonymous]

It was BLI who did gave me an information about by using locomotiv with Lenz digital system.

agge [8D]

[Tilden]

Hazmat, I am using a MRC auto reverse module on one leg of a Y and have not had any problems. Wiring doesn't get much easier than four wires, to to the mainline, two to the loop and you don't have to throw a switch.

[Anonymous]

HAZ - if you're getting an MRC PA, here is the link to ALL MRC DCC manuals in .pdf format. They have a great drawing of how to do a reverse loop and they also have an auto-reverse loop module for their DCC system. http://www.modelrectifier.com/resources/resourcesTrainControls.asp

[Anonymous]

You will need two insulated rail joiners. If you want to be cheap (like me), you can wire in a DPDT toggle switch for manual reversing the voltage.

[railandsail]

Anonymous

Lenz has one reverse loop,that you can connecting with DCC power.It`s name:LK 100
I have one Lenz SET100 with V 3.5 and can also driving doubleheaded BLI locomotiv with sounds and doing reverslooping with LK100 without loosing sounds too!
I`m not so sure, if you can using Lenz LK100 with other DCC components!?

agge

 

So you are pretty satisfied with the Lenz LK100 units??

I don't know much about the subject of reversing loops with DCC.

[hon30critter]

Hi Brian:

I don't think you are going to get an answer to your question from the previous poster because he/she is no longer participating on the forums. When the term "anonymus" is used to refer to the author of any post it indicates that the person has withdrawn from the forums for whatever reason.

You should also be aware that you have asked a question on a thread that is 12 years old. The last post was in 2006. The technology referred to in the thread is likely way out of date (I could be wrong).

I'd suggest starting a new thread even though questions about reverse loops have been asked numerous times in the past. I suspect that you have already tried the search function. The search engine on the forums doesn't work very well.

Dave

[richhotrain]

railandsail

I don't know much about the subject of reversing loops with DCC. 

Brian, a reverse loop, or reversing section as I prefer to call it, is simply the result of joining together two tracks with rails of opposite polarity.

If you think of the two rails each being a different color, it becomes easy to visualize the problem. Where the two different colored rails meet, it creates a short. The solution is to isolate the reversing section by inserting gaps in the apppropriate locations and then wiring the section separate from the rest of the layout.

An auto-reverser is used to flip and match the polarities or you can do it manually with a DPDT switch.

Rich

[railandsail]

Hi Rich,
I do understand the reverse polarity of the matter.

One question that nags at me is what happens when a loco comes to this particular point of track where the reverse polarity is desired, and yet it may have one set of its wheels (front truck) on the 'new section', and one set (rear truck) on the 'old section'? Seems to me to be a conflict??  Did I explain that correctly?

And if one is operating with DCC and sound, and wants thing to accure automatically??

[railandsail]

hon30critter

I don't think you are going to get an answer to your question from the previous poster because he/she is no longer participating on the forums. When the term "anonymus" is used to refer to the author of any post it indicates that the person has withdrawn from the forums for whatever reason.

Thanks Dave I had not realized that.

I just happened across this forum subject when searching for Lenz LK100.

I do need to do a little more reading on this subject of reverse loops. I would like to have them as foolproof as possible without a lot of complication in electrics??

[ROBERT PETRICK]

railandsail

hon30critter

I don't think you are going to get an answer to your question from the previous poster because he/she is no longer participating on the forums. When the term "anonymus" is used to refer to the author of any post it indicates that the person has withdrawn from the forums for whatever reason.

 

Thanks Dave I had not realized that.

Still, it's good to see that you did some searching of the archives before asking questions.

Robert

[richhotrain]

railandsail

One question that nags at me is what happens when a loco comes to this particular point of track where the reverse polarity is desired, and yet it may have one set of its wheels (front truck) on the 'new section', and one set (rear truck) on the 'old section'? Seems to me to be a conflict??  Did I explain that correctly?

And if one is operating with DCC and sound, and wants thing to accure automatically?? 

The reversing section will change polarity to match the adjacent non-reversing section. So, as soon as the front wheels of the loco cross the gap from the "old section" (non-reversing section) into the "new section" (reversing section), the polarity in the new section will match that of the old section.

As the front wheels of the loco cross the gap to exit the "new section", the polarity in the "new section" will match the section that it is entering. This is done automatically and electronically by an auto-reverser, and it happens so quickly that the momentary short is not a factor.

Rich

[MisterBeasley]

HAZMAT9

I would like to run the set up on DC to test the track out.

Auto-reversers don't work the way you would want them to on DC.  They are DCC-only devices.