# wiring help



## gsbnfhawk (Oct 6, 2011)

My sons and I have just started getting into HO trains and with the help of my wife we designed a cool (but complicated layout) that has a figure 8 inside an oval with a side rail off of the oval. I believe for wiring I need to wire as a double reverse loop but it has a criss cross in the middle. Please see the attached basic design. Any suggestions on where to put the insulated track rails and how to wire it, if at all possible. Thanks


----------



## Artieiii (Apr 25, 2011)

I would not even know how to help you wire that nightmare. Consider this layout. I did this in HO scale on a 4x8 sheet of thin plywood. It only required 2 swtiches at the bottom of the figure eight and there are no reversing loops to contend with. You still get your figure 8 and your mainline around the outside but wiring is simple just hook up the 2 wires to your transformer and you are all set.
-Art


----------



## T-Man (May 16, 2008)

Isolate the ends of the X at the switches. The poarty must match the loop as the train enters the X, The outer loop will have to change polarity when the train reaches it.

You could make it simpler.


----------



## Brakeman Jake (Mar 8, 2009)

Not that complicated at all...the only lengths of track that will need to reverse polarities are the X shaped tracks in the middle.Now your options....

If you'll be using DCC (you didn't say),then you'll need one polarity reversing device for each one if you are to run more than one train at a time.But if you're to run one single train,you can have both these tracks linked to a single reverser.

If you are to run DC,then you'll need a polarity reversing switch for each.A DPDT switch will do.Atlas does make a controller designed for this also.


----------



## gsbnfhawk (Oct 6, 2011)

Thanks for all the advice. Brakeman Jake, By the way I am running DC. I have ordered an EZ command automatic reverse loop switch. I am hoping this will work instead of having to switch manually. I was thinking I would only have to isolate one of the reversing loops at ALL the switches that connect to that loop. I hope this is correct. I will try experimenting this weekend and let you all know how it works. By the way Arteiii, I appreciate the design and I kind of like it but already bought all the switches and my boys really like the one Mom designed, so going to make a go of it. If all else fails we have that to fall back on.


----------



## Brakeman Jake (Mar 8, 2009)

Most sorry to have to tell you...EZ command is a DCC system and I don't believe their polarity reversing module would work with DC.I may be wrong here but I think you'll only fry the device.

I don't know if any reversing system does exist for DC but if so,someone on this forum will certainly let you know.To my knowledge,DC and DCC are two different worlds,electrically speaking,and don't inter mix without a strange smell.

Buy the way,you'll need to isolate both ends of both the X legs of your layout.


----------



## NIMT (Jan 6, 2011)

gsbnfhawk,
Brakeman Jake is correct there Isn't an automatic polarity reversing unit on the market that I know of that works with DC. And yes hooking up a EZ command switch will either fry it or do nothing at all, I've been told that you will let the magic smoke out of the unit and for $80 some bucks that's and expensive oops!
Your going to have to isolate the X then install a switch to control that section, The atlas selector switch is the easiest way to hook it up other wise a double pole double throw can be used, the disadvantage of a layout set up like this is the confusion that the center block can create.







Hope this helps


----------



## tjcruiser (Jan 10, 2010)

Jake, Sean -- nice explanations, above.

Re: the DPDT option ... here's a recent discussion on using DPDT's for circuit polarity reversal ... different application, but the principal and general wiring would remain the same.

http://www.modeltrainforum.com/showthread.php?p=88362&postcount=80

TJ


----------



## Brakeman Jake (Mar 8, 2009)

I can't help this gentleman as to designing or buying an automatic DC polarity reverser,however I have a high tech solution that would solve the confusion problem.I have done this on a somewhat similar test layout I had built a few years ago.Beware,it is highly complicated....

Here goes...take four very tiny 12 volt bulbs (like in automotive instrument panels) and install one at each of the insulated joints,with the leads bridging the joint on one of the rails (wich one doesn't matter),so that when the polarity doesn't match the bulb turns on.

Advantage...the bulb is lit by track power so no electronic gizzmo and reasonable cost.The drawback,its intensity varies with the throttle setting.It's not perfect but it tells you if you can enter...light is on....do not enter before flicking the polarity switch.


----------



## Brakeman Jake (Mar 8, 2009)

There's a major point that's been forgotten that just crossed my mind...being able to change the polarity to enter the X legs is resolved but how do you move out back to the peripheral loops?This means that you will have to have the rest of the layout linked to a polarity reversing switch so that the loco can exit.Now that's fine if you run only one train at a time since a second train will immediately reverse direction as soon as you flick the switch.Wanting to run a second train will require a more complex wiring schematic called "block control" and I believe it may be more than what you bargained for.


----------



## gunrunnerjohn (Nov 10, 2010)

Seeing this discussion reminds me why I do O-scale.


----------



## NIMT (Jan 6, 2011)

Simple fix....Go DCC this is one of the reasons it was created!


----------



## gsbnfhawk (Oct 6, 2011)

I wanted to thank everyone, again, for the help/advice. I have not gone DCC yet, as this is our first project (sons and I) and I already had some DC components and did not want to spend all the money to go DCC if they were going to get board. Although, I have been having fun even with this frustrating electrical layout.

An update on the project. I isolated the X in the center of the layout from the rest of the the layout. I wired a DPDT switch that has the center prongs powering a track on each half of the X. This allows me to switch the polarity of the X. The rest of the layout is powered directly from the transformer.

Everything seems to work well except that if I have the train do one reverse loop, when I do the next reverse loop I have to flip the DPDT switch simultaneously with the direction switch on the transformer before I enter the X, otherwise the train goes backwars and or stops. I am not sure if there is a fix to this problem, and if not, it is not that big of a problem.


----------



## Brakeman Jake (Mar 8, 2009)

The cure is simple...have the outer loops wired(all together,no need to separate them as you don't have polarity conflicts between them) through a DPDT switch as you have for the X legs so that you'll change the polarity of the layout so that the locos can exit the X legs.Just read back my previous responses wich explain how to do it and also a simple way to warn of conflicting polarities (with small bulbs).


----------

