Fully Automate Your DCC Reverse Loops (197) 

I’ve enjoyed my reverse loops for continuous running. I like your options and presentation! Thanks for sharing!

Great system Larry, love your elaborate explanation!

Very ingenious! Thanks again for another invaluable "how-to" video.

Thank you for the detailed illustration on setting this up Larry! i have learned and enjoyed many of your programs and look forward to utilizing these techniques on my new layout which I am on the cusp of beginning. I will have 2 reverse loops in my new configuration and plan to utilize this program as a tutorial when I get to the track stage.

Excellent information Larry. Thank you for posting these valuable videos!

Thank you Larry, what an ingenious Method of dealing with changing the Polarity on Reverse Loops.

Excellant work and explanation. I can't wait to build my railway room again.

I love it! When you said "the intent is to get the dad gummed thing turned around" , I lost it! That is exactly why I love your videos! I mean this with all due respect and adoration. You do a very good job explaining things and are truly a blessing to this hobby!

Good job, Larry. At first it eally looks complicated but the way you explained everything it all make sense.

Nice video Larry. I like the use of these new products to simplify operations of the reverse loops and also set up non-derailing turnouts. Regarding DC operations, if the reverse loop is operated unidirectionally, a way to allow operation through it without stopping is to use a rectifier. By putting it between the output of the direction switch and the reverse loop track what happens is that as the train runs through the reverse loop, when you through the direction switch the rectifier maintains the correct polarity in the reverse loop, thus the train doesn't change direction. AS a result you don't need to stop the train.

Thanks for another great video. Tam Valley Frog Juicers have saved me a lot of time wiring the frogs and making my N scale Peco Electrofrog turnouts and double crossover "DCC Friendly" and they also have the added bonus of being able to be used as a auto reverser for wye's, reverse loops, and turntables. Well worth the cost. Aloha

That was a very interesting video Larry. Thank you.

Nice demo Larry thank you Take care Julian

Thanks Larry. You always make things easy to follow and understand. I am about to install a couple of reversing loops using PSX-AR. I think I know what to do but if you were to do another video on this product, I'd love to see it. The PSX-AR is single device that does the whole thing - reverse the polarity plus throw the switch to the correct direction.

That's so cool. I have 4 reverse loops, 2 upper and 2 lower. I use digitrax ar1 auto reverser to change the polarity after I'm in the loop. I have to remember to throw the switch for my turnouts. But with this setup it fully automatic.

thank you for detailed video with use DCC in reverse loop

Thank you, Thank you for the clear and detailed video, although I had to use BD-20's which wire up slightly differently, I was able to successfully automate my reverse loop reliably using your guidance. The process has inspired me to look into more automation projects!

Larry! 5:00 Now you want to focus on what’s below your waist level? Great video, I’m glad it was about the tracks and switches instead of what’s in your britches. Lol

Larry I was able to find a supplier in Canada for the parts needed to build the reverse loop, this is excellent video, very helpful, next step build it

I felt sure that I posted a comment that this video was very timely as I had a virtually identical application planned when this video was first released but can't find it below. Anyway, after a few delays I have now completed the end-of-branchline staging yard and the reverse loop that supports it by turning the trains to re-orient them for their return call onto the branchline on a good friend's layout. The reverse loop is hidden and while the switch is technically accessible it is very inconvenient to reach over the washer and dryer and my friend wanted it automated to the greatest degree possible anyway. So, early in the new year I ordered the LM-ID detectors and the Cobalt IP Digital switch machine as Larry has used. It took a month for them to arrive from England, much longer than I had hoped but that is life the last couple of years. Earlier this week I completed the installation and wiring of these components and while I never doubted Larry it was great to see it work exactly as advertised/illustrated. I was even lucky enough that my initial guess for which signal wire went to which switch machine input was correct (a very small victory over a recalcitrant universe) so it worked a charm from the get-go, first for a number of runs with my test locomotive and then a test train. Based on Larry's experience I went straight to providing a 12 VDC power source for the LM-ID detectors. I have a 12VDC power bus for this end of the layout for switch machines and other accessories anyway so I simply tapped into it for the detectors and Cobalt IP Digital switch machine power. However the 12v supply means the Cobalt IP runs a bit slow, as do Tortoise machines at 12VDC instead of 16VDC, so if you use a lower DC voltage I recommend making the detector sections as long as possible. My installation uses a full length of flex track so 36". At "normal" track speed for this area the locomotive travels about half the length of the detector block while the Cobalt IP throws the switch points. I had been looking into how this gets done with the Digitrax BD-4 and DS64 but when I saw this video I immediately knew that it being completely stand alone and free of control inputs was the way to go. The components are not inexpensive, especially with international shipping, but when they work as advertised and enhance the operating experience to the extent that they do in this application, then they become well worth the price. I have not been the biggest fan of a few videos Larry has put out but most are very good and a few are most pertinent to me as is probably the case for all viewers. This one was almost tailor made for me and hence I see it as one of his very best. I hope others have benefited equally from this or other videos from Larry. Thanks for the help and guidance Larry, Best Cheers.

Great video. Was looking to do this but now I'm limited to a 4×4 area which is not going to happen.... Larry truthfully, I could of used all your advice 5 years ago before I built my layout., But I'm not and as we all say never finished modeling...but I'm not even close I am using most of what you teached as I'm fixing tunnel track and I have to finish doing my yard in my open closet where I have to put it and at the end of my 13+4 middle section... That's where I wanted this cause also I'm going to make a yard n passenger station. But my city is there with my elevated subway so only 4+4 room left for this... Your videos are great knowledge that I am absorbing. Thanks buddy keep it up, joe aka ( DIESEL 027)....

Thanks Larry, 🐾🚂 BearCreek Model RR, KY.

I had an "automated" uni-direction reverse loop on my last layout, I used a DCC reverser and a six inch length of spring wire with just enough tension to hold the points close but still allow my lightest car to push the points over to allow safe passage.

I preferred the Azatrax "spring switch" set up. It works great.

Awesome!

I got the "Smail" switch machine to work just like the Cobalt Digital switch machine (which you can't find anywhere) in this auto reversing configuration. Just wire the block detectors to the C1-GND-C2 connections on the Smail.

Vary interesting!

Larry, thanks for all your advice! Hopefully you can keep these awesome videos coming!

Great teachings as usual Larry. I'm having troubles getting my small brain around my reverse loop issue. for ease of explanation, i have a oval track, with a track going from one side to the opposite of the oval. I'm not sure where i need to isolate and put my reversing decoder(s)

I also use the Digitrax system, I am using circuit breakers to protect the layout in the event of a short circuit, Now I had a problem when using my PM42 set up to control reverse loops in that I've had to use sections of track at each end of the reverse loops and feed those directly from the DCS 210 controller because if I used the circuit protection, the circuit protection would operate before the PM42 had a chance to do its job. since wiring it this way the PM42 works great.

I think you needed to add power as the BD20 was not getting any power with the gaps insulated in the rails. I may do something like this and I really like the switch machines. Thank you.

I have basically a large Single Track DCC Folded Dogbone, where i one half it Loops back close to the Opposing track to give a Double track appearance. Basically imagine an open loop, Until I add the Crossover Switches. I want to Add a Single Crossover (2 Switches) between those opposing Mains. Which makes a Reversing Loop plus a straight through continuation on the back track. Confused about the Continuation cutoff past the Crossover. Tie it into the feeder off a Dual Juicer same Polarity feed as the Main Before the Crossover, opposite of the Loop feeders? Using Peco Electrofrogs modified for DCC. Manual Throws.

This is why I prefer insulfrog points! Cheaper alternative too

Great explanation, Thank-you. Two questions occur to me though, 1) am I correct in assuming that there's no complication caused by having staging sidings inside the reverse loop, and b) if this were adapted to a wye, I think I would need another juicer, 4 more current detectors, and of course 2 more cobalt switch motors, correct? A follow up discussion of wiring a wye might be a good idea for another video. Thank-you again for this; your videos have given me the confidence to believe I can move from DC to DCC and I'm really looking forward to it.

Larry Finally have my Reverse Loop built on my upper level. The Turnout is insulated on all sides Both rails. I have feeders from my main DCC bus connected in the loop. The train runs thru the main of the turnout and into the loop as it gets close to the diverging leg of turnout it stops short circuit the rails are reversed as expected. On the main line of the turnout about 24 inches up I placed a cut in the rail. I placed feeders black and red (red is inside rail) Black is the cut rail. and connected those two feeders to my Dual Frog Juicer. Also prior to the cut I have a black wire fed down to my NCE BD20 which then connects to my Black mail DCC Bus line. So far following you video all good. on the bd20 I see in your video you have a black blue and white wire. What I do not see is what pins they are connected to on the BD20 and on the Cobalt IP Digital Machine can you let me know what the names of those pins are on both the BD20 and the Cobalt ip digital? Thanks Tom

So if the straight track loco A is sitting in the "green" detection area, and the curve loco B approaches the turnout entering the "red" detection area, the turnout won't move to the diverge position. Is this the complex approach situation you referred to?

Nice presentation Larry, thankyou. I might have missed something tho, the polarity change is taken care of by the auto reverser and you needed a signal from the two sensors? When I set up a auto reverser for my turntable, I only used ( a Lenz unit) a auto reverser and no sensing devices to achieve the switching. So, I assume the load sensors are for changing the turnout?

I saw in another video they were using the Digitrax AR1. The loop was long, though no distance was given, but they connected the AR1 at both ends of the loop, saying it prevented any delay in detection when crossing into the Main Line versus just one end only. Is that necessary? I have not seen or heard of that issue before. Potential concerns when/if connecting at both ends of the loop?

Larry which version of the cobalt switch machine did you use , I did check DCC concepts link u posted, has a great diagram

Thanks for the video. If you have a wye to turn your Locomotive around. Would you wire it the same way

If the train is coming from the right, your left in the video, can you select straight through or diverging route? Or are you limited to the last position direction? I realize that this is simply a hidden turn around so in this case it does not matter. If it were applied that it is visible can you select direction, or is that a much more complicated wiring project. Thank you in advance.

Larry, why do you use foam rather than cork for your roadbed? Is it less expensive or what??? Thanks again for another great video!

Thank you so much for this I really needed this for my layout! BUT......... I do have a dilemma. One of my reversal loops is in fact a direction oriented loop which requires the train to always take a specific side on approach. What I've now learned ( which NO ONE on the internet will mention) is that with a reverse unit you MUST enter from where you exit or it will short out. Do you have any insight on how to handle this or is this NOT a job for off the shelf reversers?

I use DCC Specialties PSX-AR on my layout and they seem much simpler than this and they work perfectly..

This is great info. Thank you. I use the PSX AR and noticed in their instructions they suggest staggering the rail gaps by 0.75". I do have occasional shorting problems with lighted passenger cars that I cannot attibute to anything I can detect, yet my gaps are not staggered. Do you have any thoughts on this?

Larry, when building this in the "bowels" of your layout, the implication is that you cannot see what is going on down there, much the same as a train going through an inaccessible tunnel. I am wondering what you might think about installing a CCTV to monitor those areas that you can't see without difficulty to watch what is going on, and how that might be set up. It would actually be very prototypical; I am retired from UP and have dealt with Big Brother watching my every move both in the yard office and sitting at the throttle. I could see the benefits of such a set-up for something other than disciplining operating crews (not that I am bitter...).

How about a wiring diagram?

Larry thanks for the great video. I've been using servos for my hand built turnouts on the mainline but am wanting to automate the turnouts for a reversing move. I was interested in using the Cobalt digitals and a PSXAR. Would I still need those block detectors you used on your example? What brand are they? Thanks again.

Thanks for your video Larry. In the video the term “DCC Power Bus” is used. In some other videos you refer to a “DCC Accessory Bus”. My question is, are the red and green wires going through the headstones to the isolated track section, to the switch motor, and the clear copper to the Frog Juicer/Auto Reverser unit all on a separate power source and not track power? I have tried DCC REX using their wiring diagram and was unsuccessful. Did Mick answer the questions you had? Hoping you might make a video showing it in use. All the Best

If you were to add circuit protection (lightbulb) where would you place it? Thanks...

you could also just use ac?

Two questions: 1) If I wanted manually induce the turnout switch to change, what would I need to add to this configuration. 2) Are these modules brand agnostic? Meaning, does it matter which brand DCC controller I use? (I'm pretty sure it doesn't matter, but I want to double check.)

The only problem I had was no analog engines can run on .ass when the polarity changes it causes the train to reverse its direction at the last gap when the ar 10 changes polarity.

In the video you said that you needed to add a 12v power supply to the dcc concept sensor to make it work. Did you ever find out why that was the case fro DCC concepts? Is the 12v supply needed or is there a way to wire this to allow for the non 12v approach?

I am a complete newb to DCC and I want to make model railroad my next hobby - last time I played with trains was before 1980 and DCC didn't exist yet. Now, in today's age (2022), aren't there any battery powered locos that are managed via bluetooth/wifi that would simplify all these electric problems? I want to play with trains, not become an electrical engineer ;-) Great video! +1

Larry All my parts arrived two questions Question 1 On the BD20 you connected them to a 12 Volt power supply. Can I connect them to my 16 Volt DC buss line and put a reducer near and have a 12VDC buss line ? Question 2. On the Dual Frog Juicer DDFJ003U the same one your using. Can I connect that to my DCC accessory Bus Line ? or to my same bus line my Track feeders are on? Thank you in advance Tom

So, from previous vlogs I’ve seen you do, on every DCC turnout you power the single end and insulate the end that diverges and the end that continues straight. So in addition to insulating the double end do I need this device as well?

I want to construct a layout with a reverse loop where the loco enters on one turnout and leaves on another. My dilemma is whether one AutoReverse mechanism will open the forward turnout and close the previous turnout simultaneously.

You know Larry.... I would gladly subscribe and hit the bell if you would explain how the items are connected. The command, breakers, and booster

Can I add sidings or a run around track inside of the loop?

Larry , did you resolve the 12 volt power issue, I want to combine this with a helix similar to the one you are building now , a great combo , can you post a wire diagram for this set up , excellent job , I love this

Larry, I appreciate the video. I am planning to use the DCC Specialities PSX-AR. I have one question. You fixed the auto switching and poliarity from within the loop. How can you pre determine the switch machine to go left or right from out side the loop when approaching the loop. What you had just takes the last direction used.

Was the polarity in the loop changed or in the feeder main?

perfect timing for me , very interested in the cobalt rex option, once you get it clarified with DCC concepts.

When you think you are good at controlling reverse loops then try wiring turntable bridge rails.

Will this setup work with the "Smail" switch machine in the same fashion?

Sooo . . All of the track, wiring and electronics are UNDER your layout ? ?

cant we use a bridge rectifier? its so simple to use it

Just a quick question.... I watched dwarf signals episode, and did not see anything about wiring signals with snap switches... Is it just automatic?

So does a Tortoise switch work the same as theDCC concespts IP Digital ?

I'm learning about reversing sections on DCC layouts by watching videos and reading text from many sources. Some folks talk about reversing polarity, others talk about reversing phase because they say the DCC signal is AC not DC. (And some say it is not an AC signal, it's a digital signal.) So which is it, polarity or phase? It cannot be both, can it? Let's get everyone one talking about what it really is so newcomers like me can learn it right the first time. I understand that with DC powered layout it really is polarity switching but we are talking DCC layouts here.

Larry What size track did you use? I mean I see the Atlas turnout #4 #6 561 562? which Number? and then the curves what radius. 15 18 22 ? trying to design my Reverse loop for my upper level building a helix to go from one level the next

Also, which Atlas turnout did you use?

We are having a discussion on the MR forum as to whether an insulated metal wheelset (no car lighting involved) will trigger a reverser. Can you shed some light please?

Do you have a video on a Y?

Electro frog switches are more difficult then insulfrog do to the wireing in volved

What do you use for your layout looks like a hard foam board?

Dear Sir, I am a beginner in this hobby.. I hava small Kato Unitrack HO scale layout at home. Iam planning a DCC Double reverse loop in the layout.. I have some products from DCC Concept in UK.... I have very little knowledge about the loops.. I would appreciate if you help me with the wiring..can you send me a diagram..a sketch drawing of the wiring..Would it be possible to this loop with my HO scale Kato Unitrack and 2-850 / 2*851 powered turnouts...Best Regards... Kamil Işıldak..

Larry, Is there an email address that I can email you a somewhat complicated reverse loop question? Thank you, phil wells.

No 1 menckens that the layout is a loop in its self & if the party is different or reversed you need a gap ass long as your train is also you need a ar 10

way over my head,

lionel is so much easier for kids

No more ar 1 on my layout .?ar 10 much better.

you are usually much better then this, you took a pretty straight forward topic and made it way complicated.

But technically that's only half of a reversing loop.