I am presently wiring my trackwork for DCC, but cannot afford DCC equipment for a few months. I have a two track mainline with reversing loops at each end that i know i can wire to work automatically with DCC for 40 or so bucks per loop. Right now i do not have the funds available to buy four fancy auto polarity adjusting circuits, but would like to have continous running for a couple trains. I thought about just laying the track initially as a dogbone and changing it to reversing loops when i can afford DCC, but am wondering if anyone knows of any simple electronic project i can build for ten bucks or so to detect when the locomotives enter the reversing loop and change the polarity on the mainline? I've finally got a nice long mainline and would love to have a passenger train running one way and a freight the other while i sit in my easy chair sipping tea and relaxing. Any thoughts? Thanks, Curt
A straight DC dogbone would seem to be the way to go. Of course you won't be able to use crossovers. If there is a circuit to use with DC which automatically would change polarity, you wouldn't want to change the mainlines polarity or the other train will change direction. You would want to change the loops polarity. I don't know of a way to do this automatically with DC. That doesn't mean it can't be done. You can use just one reverse module for all four reverse loops as long as you only enter and exit from one at a time. This way you can spread the purchases of reverse modules over time. (This for when you go to DCC) Gary
I appreciate your observations Gary. The two train running thing was based on the fact that i have a two track mainline and would have double track return loops as well-a little tricky with crossovers i know, but doable. Thanks, Curt
Curt, for what you describe switching the 'main' is the correct, if illogical sounding, method. In principle all you need is to power the 'main line' through a relay that is energised when the engine/train is inside one loop and deenergised when it goes through the other loop. The classic way to operate the main relay is to use a latching circuit controlled by reed relays buried in the track inside each loop, with a magnet under each train to operate them. That last part is the irritating bit! To avoid modding the engines or a car in each train you would need another kind of detector, such as current sensing, optical, etc, and that will usually bump the complexity and cost up a notch. This site has some circuits listed: http://members.home.net/rpaisley4/CircuitIndex.html but I haven't looked at them myself, so can't say if they are any good.
Mike, If I'm not missing something (a good possibility) then the suggestion you made would work for operating one train unattended. I think what he is looking for is to operate two trains, on what at least would appear to be double track. I say "appear" because we are talking dogbone, which is really two one track mains next to each other. Wired as a circle, crossovers present a problem. Making the turnback loops reversing loops enables wiring the two mains as a true double track main, crosovers no problem. My suggestion is: Let two DC trains chase each other with no block wiring for now. Don't spend time and money rigging up something which is temporary. Save for your DCC system and get it asap. As I stated in previous post, one reverser module will be sufficient at first, as long as you enter/exit one at a time. If you are using diesels which draw power from all wheels, the MRC reverser will work for you. I am replacing all my MRC units with ones from Tony's, as the MRC ones don't work for steam locos, at least in my experience. I have a few I will sell for $20 if you are interested. Gary
My finance problem is one of working a "pay when job is finished" contract with new extensions being added on that are dragging it out several extra months-they make it well worth the extra time, but it does limit me in my RR plans-when it's finished i'll be able to buy anything i want-a first in my financial life. Meantime, i have plenty of free time to work on my RR and relax, but just have this two train running independently locked in my mind. I have enough track to make two complete dog bones, but this would mean a four track mainline, and there is an area too narrow for that as the layout passes thru the laundry room hallway. Meanwhile i can see if a circiut exists like i envision while i still lay track that will not be affected by my final decision. Still having a ball! Thanks for continued input, Curt
I have to agree with Gary. If you are going to get a DCC reverse module anyway, you should just save your money and wait until you get one. The temporary solutions with magnets and reed switches will eat into your money for a DCC module, plus cause you time and frustration. If you can get by without the reversing sections, then do it. Or, if you really insist on it, buy some extra track and make it a non reversing loop, if possible. You can change this later of course. If your money is tight, don't blow it on temporary electronic solutions. Be patient and spend it on the permanent solution.
Gary, looks like I was the one that missed something . Curt, if you are describing what I think you are then I'd go with the other suggestions - simple dogbone or straight to DCC! (Buy a DCC on a credit card at the right time of the month and you'll get nearly 2 months grace before having to pay up .)
Thanks for a lot of thought provoking input from everyone. What i like about the feedback i get from here is that you guys come up with alternate solutions. I have decided to skip the idea of return loops completely, for now at least, and go to two tracked dogbone all the way. I have plenty of track for the four track mainline it creates, and this will be an impressive sight in itself. This decision is made in conjuction with another-to scrap the idea of a two level layout. I had built a steady 3% grade along the wall for 46', and by scrapping that i will gain an additional 5" in depth which will easily allow the 4 track mainline width thru even the narrowest streach in the hallway. I have a 70'x16' mobile home that i can build a layout all around, plus a couple places for peninsulas, so two levels is really a bit of overkill for me. Sometimes little decisions help change big ones, and i feel very good about these changes. Thanks again for all the help and for listening! Curt
