How many feeders?

[Blind Bruce]

From what I have read, there should be a quantity of feeders per "section" of railroad. How many is actually required, say, for a single oval of track and six sidings? Layout is HO and is 4X8 feet (so far) One of the sidings will probably be a program track.
BB

[Javern]

not sure there is a SET requirement, depends on your power supply I suppose. I have one about every 20 feet of track.

[Anonymous]

Also depends on if you're doing DC or DCC. You'll usually want more feeders with DCC to keep the signals to the loco decoders strong.

[cacole]

There is no "right" answer to this question. When I wired our club layout, I put a feeder at every flex track joint just to be on the safe side. Wire is cheap, so don't be too conservative. A little extra time and effort now can save you a lot of aggravation later.

[Blind Bruce]

Thanks guys,
Cacole, you are right! I was just being lazy.LOL
BB

[Anonymous]

I'm going to run feeders to the bus every three feet. I'd rather do it now than later.

[Anonymous]

It depends on a lot of things.

Do you solder your joiners? If so, I'd say that the feeders should be no more than every 10 or 12 feet. On a 4X8 layout (loop) that's one on each long side of the layout.

If you don't solder your joiners, I'd use a feeder for at least every other track section.

If your yard is isolated, of course it'll need a feeder.

If your joiners are not soldered on your turnouts, you'll need a feeder on the first track section on each side of the turnout.

Mark in Utah

[grayfox1119]

The best practices for DCC state that you should have a feeder at each 3' section of track at the rail joiner, which will be soldered as well. It is best also to leave one rail joiner unsoldered every 12 to 20 feet to allow for expansion due to temperature differentials, to reduce the chance of kinking. If you have a well regulated room, temperature-wise, you can get away without doing this. A DCC signal is a pulsed signal at a given frequency, so you really want to make sure that the signal is as strong as possible at the decoder. As stated by others, wire is cheap, and you do this job ( hopefully) once, so do it right, don't skimp, or you will be a sorry lad for sure. Good luck with your layout, keep us updated.

[Don Gibson]

The original idea of 'feeder's' was to achieve 100% uniform power distribution and eliminate voltage drop from rail resistance (copper vs. n.s.). In practice, DCC signalling was improved; however to achieve 100% reliability, one need's to connect to EVERY piece of track - no matter how small.

Flextrack is 36"-39" long. Sectional track and turnout's are 9"- 12". I

If you want to trust your rail joiners to carry the current, fine, but oxidation and contaminant's will eventually thwart their electrical ability . tt's YOUR railroad.

[selector]

Do you ever wake up in the middle of the night and hear......................

That's oxidation!!!!

[:o)]

[mcouvillion]

I once re-wired a guy's switching yard where every individual rail had a feeder to it - even the ones that were only a couple of inches long! It had been originally wired by an "expert" who only put a couple of feeders in for a massive yard. I was tired of always having to use the "0-5-0" to help out, so, since I had to get under the layout anyway, I wired everything! Ran real well.

Essentially, you can never have too many feeders, unless you get the polarity wrong, then even one of those is too many! I used to solder my rail joiners, but no more. I'll solder a feeder to the side of the rail, somewhere in the middle, and never look back. I always want to run it for a while to make sure I didn't miss something. Fixing problems is tougher once the ballast has been applied.

Mark C.

[Pruitt]

I have feeders every 15 feet or so. Rail joints are soldered only on curves.

In many years of model railroading (around 35 now - geez, I'm old!) in many different parts of the country (Seattle, California, Wyoming, Florida, New Jersey), I have
N E V E R
had a problem with rail joiners loosening up and not conducting electricity properly.

Heresy!! But I have better things to do than solder feeder wires until I'm blue in the face. So I guess the Gods of righteous Model Railroading will be coming after me in my sleep now!

Then again, I DO prep my rail joints by cleaning the underside and sides of the rails at each joint with a cutoff disk at low speed in my Dremel. Provides fresh bare metal for the joiner to grip.

[jimrice4449]

My "bullet proof" method is to solder a feeder to every other rail joiner and then solder the rail joiner to the rails on both sides. This, effectively gives you 6 ft. rail sections w/ a feeder to every section.

[claycts]

Mark C, soldering in the middle of flex track makes sense. I was thinking (at my age that is good) that I would put a pair of 18" pigtails on every piece of flex track at the bench before it gets to the table. That way i could use a resistance system and only have the little pieces to do at construction.
Yea or nay?

[Blind Bruce]

I can't speak for Mark C but I sure will give the bench soldering a try. The feeders in the center make sense to me also. It should be much easier to solder one, solid, lead on a rail than try to flow solder into a crimped joiner. I give it a "yea"
BB

[grayfox1119]

Again, the soldering the connectors, and having feeds to the rails more frequently, is FAR more important when running DCC. You can get away with much more with DC. I have a Christmas display that covers 16 feet of 4 feet X 4 feet 3/4" tables. So every year, we set up the tables and use E-Z track for the layout. NONE of the connectors are soldered ( obviously) , but we are only running DC at this time. In 10 years of harsh New England temperature and humidity extremes, we have never experienced any power problems with any of the locos run on the layout, which has one large loop of approx. 70 feet, many curves around mountains , with only one power feed. If this was running DCC, we would be in deep doo doo .

[claycts]

Thanks people, I am using 600 ft of Code 83 with 80+ turnouts and full DCC. I was getting ready to start benchwork next week, as soon as I fini***he room that is, and these type of threads have saved me a lot of time and money.
Thank you.

[Anonymous]

Maybe this sounds heretical, but just HOW do you get corrosion in the middle of a soldered joiner? If done properly, the electrical connection will not fail, no matter how long you wait. Corrosion requires air and moisture to get in. A proper soldered connection is a solid metal mass. Corrosion might happen at the edges, but the rail would have to corrode in half, not likely.

If it's a cold solder joint, you're screwed. They're generally easy to spot as you do them.

If you have feeders every 10 feet, and solder all of your joiners, then you're only at most 5 feet between feeders, and in reality you're a lot closer than that when you calculate in the contribution of the rail coming from the other direction.

If your joiners are not soldered, such as at a turnout, then you should run a feeder to the track on both sides of the turnout, and not risk having the joiner work all the time.

I'm putting in 18 ga. feeders, 12 ga. buss wire, and connecting to my code 83 track. Based on my "rules", I'm putting in 35 feeders on approximately 200 feet of track and 27 turnouts.

Mark in Utah

[grayfox1119]

Mark, he was referring to UNSOLDERED connections, which CAN oxidize under conditions of moisture present in the atmosphere of the train room. Some connectors may not be as tight as one would think, this allows moisture and air to join together to form an oxidation on the contact surfaces, which of course is a great insulator...no contact, or poor contact...no voltage or a high resistance causing a voltage drop that little resistor called "oxidation".

[Blind Bruce]

Mark, Isn't 18 a little much for a feeder? Or do you have a 10A motor to support?
BB

[Anonymous]

QUOTE: Originally posted by grayfox1119

Mark, he was referring to UNSOLDERED connections, which CAN oxidize under conditions of moisture present in the atmosphere of the train room. Some connectors may not be as tight as one would think, this allows moisture and air to join together to form an oxidation on the contact surfaces, which of course is a great insulator...no contact, or poor contact...no voltage or a high resistance causing a voltage drop that little resistor called "oxidation".

That falls back under the unsoldered joiner, where I'd suggest that you connect a feeder to each section. I agree, a loose joiner will eventually cause most people problems. There are a ew people that advocate soldering the joiners AND installing a feeder for each track section, which I feel is severe overkill. That said, it's better to be "over-killed" than still walking.....

As for using the heavier wire for the feeders, it's stranded and I happened to have it on hand. Should I be penalized for being a cheapskate?? :-P I solder it to the bottom of the track between the ties, so it's fairly hidden, and I haven't even ballasted yet.

Mark in Utah

[Don Gibson]

Soldering to Rail joiner's may improve (electrical) continuity between 2 pieces of rail ... BUT ... it creates other problem's.

the solder joint must extend beyond the joiner to the rail to be effective
the firictional coomponent allowing safe expansion is negated
distortion of the rails (bowing) can result - requiring track replacement
the resistance in each segment of rail still adds up
and soldering to the bottom's of rail joiner's raises the height off the ties - creating a bumpy joint

Since the main objective's of a feeder system is distribute voltage equally and avoid losses from 'Daisy chain-ing' pieces of rail, I suggest that today soldering rail joiner's might be considered passe'.

[Pruitt]

I guess I should mention - i'm using DCC.

As everyone knows, oxidized nickle-silver is a conductor. So only heavy corrosion OTHER than oxidation will cause a conduction problem at the rail joiner. If you've got THAT kind of corrosion going on, your motors and electronics will be in a lot worse shape than your track joints, much earlier!

I'm sure few will agree with me, but I think the "requirement" to solder feeders to every track section is one of the great urban myths of model railroading. In HO and smaller scales, the weight of the rolling stock is insufficient to cause properly installed rail joiners (i.e., tight, with rail ends aligned) to work loose. They can oxidize, but only very rarely will one experience a serious electrical conductivity problem.

[Blind Bruce]

Mark,
Even stranded wire will "wick" solder and cause the feeder to be stiff enough to flex the rail. This alone would stop me from using material on hand as it were. How do you, or propose to do, the installation of the track through the roadbed and sub-roadbed, without bending the rail?
BB

[grayfox1119]

In order to understand why having feeders every section, and using a heavier gauge wire than #18, you need to have a good background in AC and DC electronics. Those with considerable experience in MRR'g, and have large layouts, or are members of MRR clubs, know only too well what happens when you try to get by with less than what is recommended. Small layouts on a 4x8 table or smaller, can get by without too much trouble, but as they expand, bad things can start to occur, and they wonder why. Wire is cheap, solder is cheap, yes it takes more time, but done correctly, it is done ONCE.
Don't get complacent over having no problems "now". Learn from the experts, they've been there...done it.

[nobullchitbids]

Oxidized nickel-silver is a conductor but not nearly as good a conductor as unoxidized copper. This is why it makes sense to have a bus line mirroring the rail network -- voltage drop along the bus will be less than through the rail.

Handlayers have the best situation: Simply solder a feeder to the very bottom of a rail ahead of time and drill a hole through the ballast board and whatever else is in the way to the bus. If the rail be properly positioned, the hole will lie between two ties and, once ballasted, become invisible. The feeder then is soldered to the bus with a T-leg joint.

You can continue to use rail joiners if you want, but they no longer really are necessary except perhaps on curves, where the joints should be soldered to avoid ticks or kinks. If retained, they do provide an alternative path for the juice, and cutting the load on any section of wire or rail further reduces the amount of resistance, which can't hurt.

For those retaining joiners, I recommend soldering only one side of them -- the free side will allow for thermal expansion and contraction and help prevent bowing or kinking.

[Pruitt]

QUOTE: Originally posted by grayfox1119

In order to understand why having feeders every section, and using a heavier gauge wire than #18, you need to have a good background in AC and DC electronics. Those with considerable experience in MRR'g, and have large layouts, or are members of MRR clubs, know only too well what happens when you try to get by with less than what is recommended. Small layouts on a 4x8 table or smaller, can get by without too much trouble, but as they expand, bad things can start to occur, and they wonder why. Wire is cheap, solder is cheap, yes it takes more time, but done correctly, it is done ONCE.
Don't get complacent over having no problems "now". Learn from the experts, they've been there...done it.

grayfox,

Since this appears to be a reply to my post, I'll answer.

I've been active in this hobby for over 30 years, total. Though not an electrical engineer, I have dabbled in electronics and electrical systems of varying complexity for even longer than that. I AM a mechanical engineer, and my job involves me in the grounding of airframe structural elements on military aircraft. In other words - I deal with mechanical fastening for electrical conductivity at least in part for my very livlihood. Hmmm...... Almost like rail joints..... Granted, that is not transmission of an electronic signal, but it is transmission of a extremely powerful burst of electromagnetic energy that in part is to PROTECT equipment responsible for transmitting and processing electronic signals. I probably qualify as an "expert" as much as most here do.

My layout is 31 X 29 feet, with about 29 feet X 20 feet operational at this point, running under DCC. I have had no problems, and the layout has been operational for some time now. Prior layouts in other locations have been mainly DC, with one several-year foray into Command Control via Onboard from Keller Engineering. None have ever had a problem with conductivity through rail joints.

If the initial connection is good mechanically, it will stay good.

QUOTE: from nobullchitbids:
Oxidized nickel-silver is a conductor but not nearly as good a conductor as unoxidized copper. This is why it makes sense to have a bus line mirroring the rail network -- voltage drop along the bus will be less than through the rail

Unoxidized NS isn't nearly as good a conductor as unoxodized copper, for that matter. And that's why I do have a power buss under the track. I use feeders every fifteen feet or so solely to minimize voltage drop through the less-conductive rails.

So I say again - I think requiring feeders every track section is an urban myth. I think one's time is better spent ensuring the loco is in good condition, electrically and mechanically, than in connecting hundreds or thousands of feeders between buss wires and track.

But that's just me - everyone should do what they think is necessary for their own layout.

Not an argument - a friendly discussion of varying points of view. [:o)]

[grayfox1119]

Good morning Mark, you certainly had an interesting career!! Yes , many layouts can get by with feeders at greater intervals, and this is a credit to excellent workmanship. Connections are tight, soldering is great, and track/equipment maintenance is done regularly.
Good exchange of ideas Mark, I enjoy it thank you,

[Anonymous]

QUOTE: Originally posted by Blind Bruce

Mark,
Even stranded wire will "wick" solder and cause the feeder to be stiff enough to flex the rail. This alone would stop me from using material on hand as it were. How do you, or propose to do, the installation of the track through the roadbed and sub-roadbed, without bending the rail?
BB

Its easy. Simply drill a hole through the whole mess directly under where the feeder is installed. Stuff the feeder down through roadbed. subroadbed, etc. Out of sight, out of mind. The feeder is trained so that it helps hold the rail in place. No strain is placed on the feeder to cause the rail to twist or flex.

As for the need to keep plenty of slack in the joiners for track expansion and contraction, I firmly believe this is an urban myth. Of more concern is the expansion and contraction of the layout under the track due to the changes in relative humidity. The coefficient of expansion of the track is so low that it should never be an issue. If you're having problems with yout layout shifting around with the weather, then you need to make allowances or fix it. I don't anticipate any due to my construction design and location.

Those that are worried about solder causing corrosion should be very worried about their plumbing, if they have copper plumbing in their home. It's a non issue. Leaving flux all over the thin wires on the layout could be an issue though. Wash it off. Even rosin flux is a problem. Clean it off too.

Soldered connections are not a friction fit connection. Solder reacts with the metal surface that it's bonded to creating an amalgam. This is a very strong connection. I've seen soldered connections that coul literally be used to pull trucks (Fords, Chevys don't need to be pulled). When was the last time you heard of a soldered water pipe pulling apart?

I agree that most nickel-silver joiners, when used on a nickel-silver track should provide good service. Because you're using very similar metals the risk of galvanic corrosion is low. The joiner also flexes a little when applied, helping to maintain a positive pressure connection to the rail. It's not fool proof, but it's decent.

I solder the joiner for two resons:

1. To improve the electrical connection.

2. To improve the mechanical connection and render the rail into an effective continuous rail.

I believe that the biggest problem for successful DCC operation is not voltage support, but transients and intermittent voltage on the tracks. I strongly suspect that the decoders lack any decent error correcting ability, and hence can go nutso in a heart beat. My philosophy on feeders and joiners is to address that problem.

Mark in Utah E.E., P.E.

[Pruitt]

Interesting, mark_in_utah.

I wonder just how many of the "Dos and Don'ts" in model railroading that are taken for granted are urban myths?

I wonder - is there any real difference between the rails expanding and contracting, and the foundation on which the rails are laid expanding and contracting? Since the net effect is the same - kinked rail or joint gaps, it kind of amounts to the same thing, I think.

If a solder wire joint corrodes in an environment where someone is breathing, they'd better check what kind of solder they're using (rosin or acid core), and if it's rosin core, they should get out fast! They're probably corroding their lungs, too!

Over time you might see some corrosion if you store caustic materials in the train room (like lead-acid batteries, for example), but I can't imagine that you would otherwise. And other things on the layout will show the corrosion MUCH earlier than the solder on the rail! I suppose over LONG exposure someone living in Florida or someplace else where salt air is common might see some galvanic reaction at the soldered joint, but it would still be apparent in loco meachnisms long before it was obvious at the rail joints.

I agree that soldering a rail joint will improve the electrical connection over just a friction-fit mechanical connection, but so far I haven't experienced enough degradation in a connection to do all that soldering.

Mark_in_New_Jersey (go ahead and laugh - it makes ME want to cry!), also a PE [:o)]