Crossover wiring help


H

Hypnotoad

New Member
Hi All,

New to the hobby and am looking at wiring up the following layout but am having trouble getting my head around wiring up the circled section as the polarity is always going to be reversed here. I am using Peco Setrack 100 insulated turnouts. If i make a split in the circled section the whole thing works fine but obviously the locomotive can't cross the split track without shorting. I am sure this is a simple problem but I can't seem to work it out...
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Also, please ignore the fact that the track doesn't actually join in the diagram, the real life one is all nice and neat thanks to a section of flextrack. I am only running a single DC controller.

I appreciate any help I can get on this, cheers
 
You would isolate (insulate) both rails as close to the turnouts (both) as possible. Then you would use a DPDT (break before make) switch to send track power to that section. After a train enters that section you would have to stop it, flip the DPDT switch to match polarity for the way you are going and then run the train (probably have to change the direction switch too). You would wire the DPDT switch so one way the power is straight through and the other it is reversed.
 
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Thanks very much for the quick reply Tim. I see what you mean. As the half figure eight effectively flips the track there is no way to power that crossover without flipping the polarity. Might rethink that crossover part. Anyway, thanks again.
 
You will have more luck searching for thing about "reversing tracks" tracks or "reverse loops" than the term crossovers. Generally a crossover is used to mean a connection between two adjacent tracks. Not trying to be pedantic, but you will get more results if you use the reversing terms in a search.
 
My opinion only, but that plan above needs a small yard and one or two more industries much more than it needs "a reversing crossover"...
 
Hypnotoad said:
New to the hobby and am looking at wiring up the following layout but am having trouble getting my head around wiring up the circled section as the polarity is always going to be reversed here. I am using Peco Setrack 100 insulated turnouts. If i make a split in the circled section the whole thing works fine but obviously the locomotive can't cross the split track without shorting. I am sure this is a simple problem but I can't seem to work it out...
Click to expand...
As David1905 said, this is the classic "reversing loop" problem on two rail layouts. The key is to use dual insulated rail joiners on both sides of the circled portion, and then run a separate power feed to it.

If you are using straight DC power you will need to add a separate double pole double toggle (DPDT), to each the new reversing section and another to the main line. The trick is then to use the switch to the reversing section to match polarity to the main where the train is entering. Once the train is in the reversing section, the switch to the mainline has to be thrown to reverse it's polarity so it matches the train when it comes out of the reversing section.

If using DCC, one simply has to attach an automatic reversing unit to the newly isolated reversing track segment. It will sense a short circuit and automatically flip the polarity.
 
You can also throw in a bridge rectifier in line there and the train won’t have to be stopped when you throw the switch.
(You'll have to look that one up but it’s very easy.)
If you get ambitious look into adding a bi-color LED (again fairly easy) to indicate polarity, green = enter and red = hit the brakes.
Sorry for the add ins, something to do once things are going.
 
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