Cab Control?

[kylewoody]

Hey guys,

I am building (now changed) an N scale layout of both Alabama Gulf Railroad shortline, and a CSX mainline.

Anywho, DCC is expensive, and I want to do cab control - I have the basic jist of how it works, and am decent at understanding wiring, as well as soldering up connections etc. myself.

My question is this - I have seen a diagram show that one side of the track (an entire rail) is the "feeder" rail, while only the other side is insulated.

Does this work, because when a switch is set, it will travel out of the controller, through the feeder rail, through the trucks of the locomotive, going to the other instulated rail, and back to the controller, thus making a full connection?

It seems pretty simple to wire up then, with just a basic powerpack controller, a couple tougle switches and some speaker wire, no? Any good websites on it?

Thanks!
Kyle

 

[Rico]

You pretty much have it figured out!
Think of household wiring where only the hot (black wire) is seperate from the common (white wire).
On the layout a DPST switch just toggles one power to the other. A center off switch gives you a dead track for sitting a loco on.
There are lots of sites on wiring, try the NMRA site for links, I'm sure you'll also get lots of help here.
DCC may seem expensive to start out, but in the long run is much simpler to wire and saves alot of switches and such.
Something to note, alot of people say they want to go DCC so they can run like the "real trains", however the big boys actually run on cab control in blocks, the way we've been doing it for years!

 

[kylewoody]

Cool, thanks Rico!

I plan to have the shortline seperate from the mainline (they both start in the same city, though different yards - one runs north, one runs east). So, the shortline will be independent of all other track, and have it's own powerpack.

On the mainline however, it will also have a small yard with a switcher locomotive as well - so I plan to use basic cab control on that. Nothing crazy either, it should be simple (it's my first dedicated layout anyways), so hopefully I'm not aiming to high!

Kyle

 

[CBCNSfan]

Hi Kyle, the term used is common rail, that is one rail is common throughout the system. I use it on my layout. Just pick the rail closest or furthest from you as common and stick with it around the layout and you'll do ok.
However don't depend on the rail to carry the power, use lots of drop wires (feeders) just like for DCC, it's worth the effort. A set of feeders every 3 feet or so should do it. If you then decide on DCC you'll have it made.

Cheers Willis

 

[kylewoody]

Hey Willis - when you say feeder wires, do you mean just soldering on some short (say, 3") wires, from one section of flextrack to the next? I would guess, you could run this under the track, and either in between the roadbed, or even under it too?

Thanks,
Kyle

 

[Rico]

A feeder wire is a small gauge line that drops down from the rail to a thicker gauge wire that runs along under the layout.
It's best to use one color for the common rail and another for the "power" rail.
The idea is to not rely on rail joiners for conductivity.
As Willis mentioned, pick one rail for the common, make sure it's the same rail when the track curves around and faces the other way too!
Try googling train layout wiring, should shed some light.
Rico

 

[kylewoody]

Oh, okay. So basically, those wires would supplement the metal rail joiners, right? They don't go to anywhere else (like a powerpack or anything), they just jump over from piece of track to the next - helping the rail joiner's out?

Kyle

 

[UP2CSX]

Kyle,
No, you don't have the idea quite right. You run two wires from the power pack underneath the layout, following the general layout of the tracks. Remembering which rail is common, you attach two wires to the wires under the layout (called a bus). This can be done by striping back the insulation and soldering or using so-called "suitcase connectors". I've been using a product called Posi-Tap, which makes it very easy to attach the wires with no stripping or soldering and the connection is mechanically strong and electrically sound.

Now you drill two small holes through the layout surface large enough push the wires through. Once you have the wires up to the tracks, clean and flux the rail inner web surface. You can use either the outside or inside web surface. The inside web is generally easier to disguise with ballast but the outside web is easier for beginners since flange clearance isn't an issue.

Bend the stripped end of the wire so it's parallel to the rail web. Solder both wires to the correct rail, again remembering which rail is common. It shouldn't take more than few seconds but sometimes having a small piece of wet sponge on both sides of the wire joint helps as a heat sink to prevent ties from warping. Repeat this every three feet or so until you have feeders wired to all the track on the layout.

The issue of rail joiners is completely separate. The rail joiners will not provide solid electrical contact between the joints over the long run. As long as you are soldering anyway, you should run a bead of solder down one side of each rail joiner so the solder touches the two joined rails or use jumper wires as you suggested in your post. I've found just soldering the rail joiners works just as well and is less work than jumper wires.

 

[Rico]

Thanx for clearing that up Jim, I didn't quite add enough info!
Where do you find the Posi-Taps? Sounds interesting, I've never liked the suitcase style.
Kyle, if your layout isn't a monster you may get by with one feeder per block, or insulated section. (between insulated joiners)
Check this out for more info: http://www.nmra.org/beginner/wiring.html

 

[UP2CSX]

No problem, Rico. You can see the Posi-Tap at http://www.posi-lock.com/posiplug.html. They are now available in many auto parts stores or you can buy them on-line. They are the greatest thing since sliced bread for doing this kind of work. If you are attaching feeders three feet apart and the feeder wire is 20 gauge or less, you can attach two pairs of feeders per Posi-Tap. They work best on stranded wire so that's what I used for my lighting bus but they will also work for solid core wire. I've attached 67 street lights and building lights using Posi-Taps in about 1/4 the time it would have taken me with any other method. I hate those suitcase connectors as well because it's too easy to miss penetrating the wire and get no connection. Once you you've done this, the connector is now useless. With Posi-Taps, it's almost impossibe not hit the wire correctly and, if you do, you just take it apart and start over since they are completely reusable. Just give one pack a try and I guarantee you'll never use anything else again. I have no connection with the company, just a happy user.