well looks like yet another design, hopefully this will simplify things, I have as helix and would like to use a reverse loop to change the direction of the loco and run it back down, this loop would be hidden under the main deck, clearance is not an issue as I have laid that out, what I would like to do is instead of having just one track in a loop i wanted to have the loop handle more than one train, at least be able to have a siding while one train exits and another enters, I have a plan here , but again Im not sure where to cut the gaps in the rail, I assume at the first turnout on both legs, but there is an inner reverse loop does that matter? i appreciate anyones input as the gaps in these reverse loops give me trouble.
Since joining the forum, most of your posts have been on the subject of reverse loops and the helix and where to gap the rails.
It’s time for you to learn how to determine where to gap the rails for a reversing section.
Do the same drawing with two rails instead of one. Use a red lead pencil for the outer rail and a blue lead pencil for the inner rail. Whenever the rails meet with opposite colors, that is a reverse polarity situation and needs to be resolved by gapping the rails to isolate the reversing section.
Give a man a fish, and he’ll eat for a day. Teach a man to fish, and he’ll eat for the rest of his life.
Bob, I have books on that just thought this would be a good place to ask about a reverse loop within a reverse loop the basic books dont go into that detail. thanks but i have them, Actually now that i understand that it is a reverse loop within aloop my questions have pretty much been anwered. Thanks
I am not sure that your track diagram is a reverse loop within in a reverse loop in the strictest sense of the word, but no matter.
The drawing that follows is what I was suggesting in my earlier post about drawing a two rail track in different colors so you can visualize the point of reverse polarity. In this diagram, you can see where the reverse polarity occurs on each loop. The black dots represent the points where the rails need to be gapped to isolate the reversing sections or, in this case, the reverse loops.
For about $30 you can get an auto reverse circuit board. It works on DCC, but I think they can also be wired into a DC layout, if that’s what you’re doing. I’ve got two of these.
To simplify things, you only need to reverse enough track to accommodate the longest locomotive lashup you’ll be running plus a little extra. Here’s my staging plan, which is similar to yours:
In east staging, on the left, the reversing section is on the inner track from the end of the outbound throat up to the bridge, about 4’ of track (N scale). On the west staging, the reverser is on the inbound side, between the crossover and the first switch (about 2’ of track). The polarity of the staging tracks is all consistent, otherwise I’d be constantly reversing polarity under a whole bunch of trains. Using the short single track just makes wiring the whole thing easier.
The benefit of an auto reverser is you don’t have to stop the train. The circuit detects the reverse instantly when the wheels bridge the gap (you still have to gap both rails at both ends of the reversing section) and reverses the polarity seamlessly. If you’re running DC, check the manufacturer’s spec to see if it will do the trick. In any event, it will save you a ton of head scratching.
Incorrect, unless you run all plastic wheels on all your cars. You want the reversing section to be big enough to handle an entire train. If you have freight cars with metal wheels they can cause a short when momentarily bridging the gap. It may be quick enough to actually not trip the circuits, but if you run lighted passenger cars it definately will.
I just wanted to thank everyone for all your info, it has been a big help, got my reverse loop in with double tracks attached to a dcc specilaties auto reverser and it works great!! thanks again to all for helping out!!!
and i understand reverse loop s a heck of a lot better than i did before.
That can cause an issue if the train just happens to be exactly the right length for the engine to hit one gap and the caboose to be on the other. Had that exact thing happen on the club layout once, with one of the new Rapido Trains HO cabooses, which have track pickup for lighting.
In most cases, metal wheels rolling across the gap will probably be fast enough to not affect the system, but it is possible for that to cause a short.
