# DCC and track feeds



## Againtrains (Mar 6, 2016)

I just don't get it. I see so many posts about you need drops every 6 feet. Why? I have a 12 feet of bench work in a L shape with 2 loops of track, another half loop of track. So if I do the rough math right 60 feet of mainline not including sidings. Divide by 6 means 10 feeds....hmm I have 4 drops and 1 is not hooked up. Talking to people at the train show you don't need all the drops if your track work is good. My 2 cents on this subject.


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## Shdwdrgn (Dec 23, 2014)

Even the best track work builds up corrosion over time. Everyone's track works great the week they set it up, but not everyone has good soldering skills. Rail joiners corrode, non-soldered wire drops corrode, motors wear out and become more sensitive to voltage changes... There's just too many things that can go wrong, and a large number of wire drops helps safeguard against those failures.


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## gregc (Apr 25, 2015)

i agree that the need for feeds every so many may be overblown

but even if you soldered all your track joints, nickle-silver rail is not as good a conductor as copper. And soldering all your track joints may not be the best thing considering expansion if the rail lengths are long.

(like you, I have a small layout and with isolated turnout frogs, i need the feeders and I solder rails because the lengths I have are so short.)


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## DonR (Oct 18, 2012)

Your skepticism is understandable. We talk in
generalities here on the Forum much of the time.

The suggestion of track drops every 6 feet is one
of them. I haven't actually measured the distance
between my layout drops, some are less than 6 feet to
feed tracks connected to power routing turnouts,
yet some other track stretches could be 10 feet or so,
from drop to drop. The use of 3 ft long flex
track is a big help by reducing the number
of joiners where problems can show up.

All has been well for several
years, but as Shdwdrgn has said, after time
corrosion can set in and that is a problem I am
battling with my turnout electrical contacts. 
Contact cleaner to the rescue.

So, in short, your 4 or so drops in 60 feet is not
that far from the 'norm' especially if the layout is
in a climate controlled area.

Don


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## tankist (Jun 11, 2009)

I agree with OP's sentiment. Feeder drop every 6' seems excessive. testing my helix I don't have permanent wiring yet. 5+ sections of flex (soldered) are connected to the powerpack at one end via aligator clips. There are no power delivery issues to the very end of the powered section. 
I'd say for smaller home layouts with max of 2-3 engines running at time the above recommendation is an overkill.

That said for permanent wiring of my helix section I already have two feeder drops soldered on each level one above another. so I'm overkilling it too 🙂


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## MatroxD (Jan 19, 2018)

I think that it probably is overkill also,but I'm overkilling myself.. My thought is based on the old layout stuff when I was growing up. On my "small" 8x4,i have kinda 2 ovals.. On each, I have a drop on each side of the oval (both sides and both ends), so on my tiny layout, I have 8 drops. I never really thought about it until now honestly.. And I also use flex track.

I guess I figured it's better to be safe than sorry,considering things that can happen and my luck... 

Sent from my Note 8


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## CTValleyRR (Jul 26, 2014)

Againtrains said:


> I just don't get it. I see so many posts about you need drops every 6 feet. Why? I have a 12 feet of bench work in a L shape with 2 loops of track, another half loop of track. So if I do the rough math right 60 feet of mainline not including sidings. Divide by 6 means 10 feeds....hmm I have 4 drops and 1 is not hooked up. Talking to people at the train show you don't need all the drops if your track work is good. My 2 cents on this subject.


You're absolutely right on this. I'm the resident contrarian here when it comes to both benchwork and wiring. I think too many people go overkill on these. My son's 8x8 layout runs just fine (DCC) with rail joiners and a single pair of AWG 22 feeders.

What it really comes down to is risk management. How tolerant can you afford to be of power continuity issues? If a spot starts giving you trouble, adding another feeder pair isn't that big of a deal, but it's not something you're going to want to do in the middle of an operating session with 24 people trying to run your layout. My advice is always to start with the minimum, and beef it up if you need to. My layout has one pair every 10 feet or so.


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## flyboy2610 (Jan 20, 2010)

It's more than just a power continuity issue. It's also a safety issue. 
I posted this previously, but I'll repeat it here:

You can run a fairly decent sized layout on a single set of feeders, but I wouldn't advise it. The reason has to do with short circuit detection. I'm no electrical guru, but in essence the farther away the short circuit occurs from the DCC power drop, the less likely the DCC unit is going to be to detect it. I think it has to do with voltage drop, but don't quote me on that. An easy way to test your layout is to place a quarter across the rails at the farthest point from the DCC power drop. If the layout doesn't shut down instantly, you need to add more feeders. The DCC unit is still putting amperage through that short circuit, and it can heat up the metal object until it is hot enough to catch fire.
Just think of feeders as fire prevention. 
What's your home worth?


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## Lemonhawk (Sep 24, 2013)

I think the 6' comes from soldering 2 3' sections together that will be connected with non soldered joiners to account for expansion and contraction. That's about the only justification for the 6' I can think of. It's a nice idea, but only if you want to do the track laying that way and put up with all the feeds.


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## gregc (Apr 25, 2015)

Lemonhawk said:


> I think the 6' comes from soldering 2 3' sections


if you add a feeder to the soldered joint of every other rail then every rail has a feeder.


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## Againtrains (Mar 6, 2016)

*Drops*

I just was trying to find out why the 6 foot rule. In the day I ran HO and dc the last layout I had had 2 main feeds. The layout was U shaped and was 15' by 35' by 10' and had loops on top of itself... It ran find that way for years. Now I fast forward to today and I switched scales to N. Started in DC had trouble with old power packs and then switched to DCC. Has the layout expanded I did not add more drops.... Even when I did some rewiring(clean up a temp mess) for a while on the 2 loops it was only 1 feed.... this incudes running with sound. I feel most of the problems is if you have dirty track. Yes I have had some shorts but the system catches it. Just my 2 cents...… :laugh:


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## Lemonhawk (Sep 24, 2013)

Since I lay rail on CV ties, I decide where I want a feed and put in a PC tie that has the connections all hidden, then after I lay and glue the rail down, I solder the rails to the PC tie, that way its all hidden. Since the layout relatively small I typically solder two 3' rails together as that's a convenient size to glue down. All the feeder PC ties are pre wired so it goes really fast. No spikes!


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## CTValleyRR (Jul 26, 2014)

flyboy2610 said:


> It's more than just a power continuity issue. It's also a safety issue.
> I posted this previously, but I'll repeat it here:
> 
> You can run a fairly decent sized layout on a single set of feeders, but I wouldn't advise it. The reason has to do with short circuit detection. I'm no electrical guru, but in essence the farther away the short circuit occurs from the DCC power drop, the less likely the DCC unit is going to be to detect it. I think it has to do with voltage drop, but don't quote me on that. An easy way to test your layout is to place a quarter across the rails at the farthest point from the DCC power drop. If the layout doesn't shut down instantly, you need to add more feeders. The DCC unit is still putting amperage through that short circuit, and it can heat up the metal object until it is hot enough to catch fire.
> ...


While there is something to be said for equipment protection, shorts are more about performance than any real safety hazard. 

I'm skeptical of the "hot enough to start a fire" thing, unless you are talking about very fine wires like steel wool, which CAN flash into flame -- but I have taught enough boy scouts to start a fire with steel wool and a 12v battery that I can tell you it's no easy task, even when you're TRYING to cause a fire. Add to that the fact that I don't leave my layout on when I'm not in the train room, and the fire extinguisher 10' away, and I'm going to file this one under "possible, but not something that's going to make me lose sleep at night".

My solar panels have a 0.004% chance of causing a home fire, and all the electrical appliances in my kitchen much higher than that, with the clothes dryer higher still. We use that stuff all the time. If I were to avoid everything that could possibly cause a home fire under ANY conditions, I'd have a pretty miserable existence.

Now all that said, I'm not advocating trying to push the biggest layout you can from a single pair of feeders, or not having additional short protection (but for reliability and equipment protection purposes), just that you don't need a pair of feeders every 6'. Most of us can make do with a couple of independently fed and protected power districts.


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## D&J Railroad (Oct 4, 2013)

They are suggestions to provide drop feeds to a buss to each piece of track. If ya don't want to do that, there aren't going to be any model railroad police to come around and confiscate your layout. It's a suggestion based on "good" electrical physics. 
When ya get to the point that ya have bump or bang on the layout surface to get a stalled train to run, don't bother with adding drops. Just keep bangin on the layout. 
As for my layout, I'll keep my drops installed, regardless of the luck that others have.


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## CTValleyRR (Jul 26, 2014)

D&J Railroad said:


> They are suggestions to provide drop feeds to a buss to each piece of track. If ya don't want to do that, there aren't going to be any model railroad police to come around and confiscate your layout. It's a suggestion based on "good" electrical physics.
> When ya get to the point that ya have bump or bang on the layout surface to get a stalled train to run, don't bother with adding drops. Just keep bangin on the layout.
> As for my layout, I'll keep my drops installed, regardless of the luck that others have.



There's good physics, and there's overkill. Good physics does not mandate a power feed every 6 feet, or to every piece of track. Adding power feeds like that is extreme risk averse behavior. It's never a matter of luck, and to imply, as you seem to be, that anyone who DOESN'T follow that practice is at high risk of some kind of electrical disaster is one of two things: just being ridiculous, or a deep seated feeling that maybe what you are doing IS overkill, so you have to justify it in your own mind.

The prudent hobbyist will add power drops at some interval that he feels will work with his level of risk aversion. Certainly, if you are unwilling to accept the risk that any piece of track, anywhere on your layout, is at any time, ever unable to get power, then by all means, throw a power drop in there every 6", if you must. That same prudent hobbyist, upon testing (which is a much more intelligent approach to risk management than just blindly adding feeders at some given interval) and identifying an area that requires an additional drop would simply add one.

The suggestion that any hobbyist who is having trouble with track power would attempt to solve the same by banging, shoving, or otherwise abusing his equipment doesn't speak well of you or do anyone any favors. Implyjng that the only choice is between large numbers of feeders and a layout that causes rage and abuse doesn't help anyone.


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## D&J Railroad (Oct 4, 2013)

Well good for you CTV. If your one set of alligator clips to the tracks works for you, great.


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## CTValleyRR (Jul 26, 2014)

D&J Railroad said:


> Well good for you CTV. If your one set of alligator clips to the tracks works for you, great.


Just trying to keep common sense in the discussion. Thanks for doubling down on stupid.


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## D&J Railroad (Oct 4, 2013)

CTValleyRR said:


> Just trying to keep common sense in the discussion. Thanks for doubling down on stupid.


I see your last resort.


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## mesenteria (Oct 29, 2015)

I have the following philosophy when it comes to minimizing work and materials usage, but also maximizing the reliability of electrical feed to all rails on the layout:

[First, though, I don't solder all joiners; I leave some to slide to allow the tracks to 'breathe'.]

I solder most joiners, especially those on a curve. Where it makes sense to do so, and where it is convenient, I solder a feeder wire to every second joiner on my layout. Where I do this, the joiner is connected, by solder, to a feeder. Schematically, it looks like this:

===x=========o=========x=======o===

The x represents a soldered joiner and a co-soldered feeder. The o represents an open, non-soldered joiner, no feeder. Open because non-soldered joiners are notoriously unreliable in terms of providing electrical continuity, so I treat them as an open circuit at that point. If you follow the logic, the soldered x feeder/joiner carries power bi-directionally until it meets the non-soldered joiner. That means two lengths of track get full power, for a total of 6 feet. On to the next soldered joiner/feeder, and you get the same thing. All the non-soldered joiner between them does is to provide alignment, which joiners do rather well....most often. But, your track system will be fully reliable for track power along its entirety.


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## flyboy2610 (Jan 20, 2010)

And there's absolutely nothing wrong with doing it that way.


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## CTValleyRR (Jul 26, 2014)

flyboy2610 said:


> And there's absolutely nothing wrong with doing it that way.


Of course not. It's a good method and logically thought out.

It's when you imply or outright claim that it's the only way, or the only acceptable feeder interval, to ensure good power connectivity that you run off the rails.


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