return loop

[Texas Zepher]

QUOTE: Originally posted by backpackingnn
I've gapped both ends after the turnout, both rails are gapped. My turnout has an isolated frog. My test train will continue to run through the turnout into the new block forwards, comes back around the loop and it shorts out as it crosses from the return loop block back into the original block. . Am I missing something?

Yes, You need a DPDT switch to reverse the polarity of the original block while the train is in the loop.

[Anonymous]

sorry, i'm using DC. thanks for the help

[rrinker]

Are you running DC or DCC? You need to flip polarity when exiting the loop. Either system needs that gas you installed.

For DC, you need to reverse the polarity of the main line while the train is in the loop. The easiest way to do this is with Atlas electrical components - you want the device called the Controller. It will have a diagram showing how to wire it. Or, you need a DPDT switch wired as a reversing switch (a wire frm each diagonal corner. power feed to middle terminals, power to track from either set of end terminals). The wire from your power pack will go tot he loop, AND to the new reverse switch. The output from the reverse switch will go to the main line. Whent he train is in the loop, flip the new toggle before the train come sout, and it will proceed normally.

For DCC - you can feed the reverse loop through an additional toggle wired for reversing, and do it manually - you can flip the polarity any time under a running DCC train and it won't change direction. Or you can look at one of the various autoreverse units on the market and use one of those for hands off operation.

--Randy

[Anonymous]

I'm having trouble wiring a return loop on my new layout. I've gapped both ends after the turnout, both rails are gapped. My turnout has an isolated frog. My test train will continue to run through the turnout into the new block forwards, comes back around the loop and it shorts out as it crosses from the return loop block back into the original block. My wiring looks good but I'm going back t double check it. Am I missing something? thanks