Hello, read somewhere that I should have feeder wires every 3' of track for DCC, but also read something that implied small layouts don't need that. I have a 10'x8' L-shape layout with a double oval mainline. Can I get some advice for how to space my feeder wires please?
More info/advice needed: this is for a DCC layout, using NCE PowerCab, I'm planning on using a 16ga bus with atlas terminal joiners for feeders - this is my first layout, I'm completely clueless on soldering. Any thoughts on this plan?
If you solder your rail joints you can fudge the spacing a little. They say "every three feet" and that will put a feeder on every piece of rail regardless of joiners.
The LION does not use DCC so him does not need to be so fussy, but him has a feeder at least every 12 feet with soldered rail joiners. But then him has other operational reasons for doing so.
Put a feeder every twelve feet and see what happens. If you like it you are done, if your layout needs more feeders it will let you know, and it is a simple matter to add a feeder at the 6' mark. If you tie that feeder to the rail joiner then both 3' sections on either side of the joiner will have its own drop. I do not see how you can get any better than that.
ROAR
The Route of the Broadway Lion The Largest Subway Layout in North Dakota.
Here there be cats. LIONS with CAMERAS
Part of it depends on if you are using sectional track or flex track, flex track has far fewer joints so there isn't as much potential for a bad connection. Or if you solder rail joints
My method has been to make every joiner, except where insualted ones are required, feeders. With flex track that basically means every 3 feet, although around a turnout that's 3 pairs of feeders, one on each leg. I would be broke if I bought the Atlas ones, instead get a spool of decent wire, I use a #20 solid that Home Depot sells as alarm wire, and a good pair of wire strippers like the Ideal Stripmaster or Klein, and then buy a pack of regular Atlas joiners. Sit down and cut lengths of the alarm wire, use the strippers to strip the ends, bend at right angles to the wire, and solder them to the bottom of a joiner. Voila, instant termianl joiner for a fraction of the price. Since you are solderign at the bench, no need to worry about melting ties, and after the first few your soldering skills will improve rapidly. Make up a batch, then start laying track. The wire I use is actually two conductors, one in red and one in white. Be consistent as to which color you use on which rail, in my case for around the room I just used Red to the Rear. The track closest to teh wall always gets the red feeder wire, the track closest to the front edge of the layout gets the white feeder. If you do something consistent, when you go to wire up all the feeders it will be easy without crossing any of them and causing a short.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
Tracks have a designated direction. The LEFT rail is (-) [or ground] and the RIGHT rail is (+).
LION'S layout is 1000' long of twists, turns and loops, but "uptown" (or North) is always the same. Tracks 1 and 3 are uptown, tracks 2 and 4 are downtown, but even that does not matter, you know which way the train is supposed to go on that track. (yes, trains *do* go either way but the mile posts only go one way.
MattDHello, read somewhere that I should have feeder wires every 3' of track for DCC, but also read something that implied small layouts don't need that. I have a 10'x8' L-shape layout with a double oval mainline. Can I get some advice for how to space my feeder wires please?
I always think about it as if the main line is one big loop. The max distance of a locomotive to power is Feet of Mainline / number of feeders / 2 or in your specific case (10+8) * 2 = 36 feet. You said double so I'll assume the worst 72 feet. With one set of feeders the train will never be more than 1/2 that distance or 36 feet. Way too far for nickle silver to carry the signal let alone dealing with all the rail joints. So add a 2nd feeder on the opposite side of the loop. Now a locomotive will never be more than 18 feet from power. Still too far. Add two more at the 1/4 points and the loco is now no more than 9 feet. I think I would, at a minimum, add feeders at the 1/8 points so that loco would never be more than 4.5 from power. At the 1/12th points would be feeders every 6 feet and 3 feet to power.
Everyone,
Thanks for the advice here. To answer some questions: I am using all flex track code 100 except for switches, where I'm using standard atlas remote snap switches, also it is a double track oval, not a double loop. So, based on everyone's advice, I'll be putting a set of wires after every flextrack, so every 3'. I'll use 16ga for the bus.
Appreciate the advice on how to make my own! Next layout (moving in 6 mos) I will learn to solder and make some of my own. Plus, I can color code it then.
I use a 16AWG bus and put feeders every 8 feet. Several people have told me that is inadequate on both counts, so I will stop short of recommending it. It is, however, working just fine on mine.
I cannot, on the other hand, over emphasize the importance of color coding your wire. Do it always, and do it consistently. It will save you a lot of hair pulling if you ever have to add something, replace something or troubleshoot a problem.
Dave
Lackawanna Route of the Phoebe Snow
The simplest solution is to only feed every second pair of joiners, but they must be soldered. That way, you have a soldered feeder at each of two rails at a joint, and the power has to go in opposite directions, but only as far as the next ends of rails, or three feet. At each of those ends, you only need to use a non-soldered and non-fed joiner for alignment...nothing else. Elegant, faster than soldering every single piece of flex, and bullet-proof. Schematically, it looks like this:
====0==================#====================0=====================#===========
The 0's are non-soldered joiners....just slipped on and the rails left in alignment. The #'s are soldered joiners but with a feeder also soldered there. If you 'look both ways' from those joints, how far does the power have to travel? Ans: a whopping three feet. Nice part is that instead of four soldered and fed joints, you only need the two shown. Saves time and material.
Crandell
Wanted to write a note and say thanks - you've all delivered a lot of sound advice a few times for me, and I appreciate the help. I don't mean to ask such basic questions, but some of this stuff can get pretty confusing when you read so much online material with so many different opinions. And a lot of the articles assume you have a base level of knowledge that, frankly, I don't have. Was wondering if you would mind helping me with just a couple more:
MattD 1. On the track power bus, I know it's one wire for positive, one for negative obviously. Each will start in its respective terminal in the DCC booster. But, does the end of that lead also get plugged into the booster? In other words, does each lead make a loop, or do the just stop at the last feeder? 2. Generally speaking (assuming no reverses, powered frogs, etc), and based on what I read here, positive goes on the "right track", so if my mainline goes counter clockwise, the positive will always go in my outside track, correct?
1. No, the ends of the two bus wires do not reconnect to the booster. They can end at the last feeder, or go beyond and have the ends taped or capped so that they don't touch.
2. I might get criticized for this, but you should probably forget about positive and negative in the world of DCC. The power out of the booster is some sort of AC, so you can't determine what is positive and what is negative like you would with DC. You should think instead of phases. If you swap the power leads between two sections of track, the leads will be out of phase and you'll end up with a short. So what you'd want to do is to make sure that all the outside rails are connected to the same bus lead, and all the inside rails are connected to the other bus lead. If you only have the one booster, it doesn't matter which bus connects to which rail as long as you are consistent. If you add another booster some day, you'll have to do some checking to make sure that the outputs from the second booster are the same as the first, but we can save that discussion for later if it becomes necessary.
Color coding of the feeders is absolutely necessary unless you like to make things difficult for yourself. There are differing opinions as to what these colors should be, but I happen to use red and green. I have a loop style trackplan so I use the "R" in red to make me remember that that is the feeder that should go to the Rear track.
Absolutely DO NOT connect the bus back to the booster at the other end.
DCC uses square wave AC and sends it's signal by varying the width of the pulses, there is no positive or negative. Your command station is probably labeled Rail A and Rail B. Direction of travel is determined by the decoder in the engine, so it does not matter which rail you choose to be rail A, What is important is that you never connect rail A to rail B anywhere on the layout. You must keep the wiring consistent, Color coding the wire will make that a lot easier.
In the interest of safety I STRONGLY recommend the Quarter Test.
With your booster turned on, put a quarter on any piece of track on your layout. The farther from a feeder the more valid the test is. The booster should shut down on over-current. If it just hums or sings you need more feeders.
My modus-operandi is to connect a set of soldered feeders to some track. Then I start going down the track with a quarter moving farther away from the last feeder. When the Quarter Test fails, I move a couple feed back towards the last feeder and install a new set. Repeat as required until you are out of track.
Failure to install enough feeders to allow the short-circuit protection to operate will cause melting of components during an un-detected short. Better to not melt the models we pay so much for - yes?
Be safe.Dwayne A
Aren't feeders only used because of the joints? If the rails are soldered like welded prototypes are, then what's the need for feeders.
alloboard Aren't feeders only used because of the joints? If the rails are soldered like welded prototypes are, then what's the need for feeders.
Feeders are used to ensure the electric current is carried through out the system. The farther from the source, the less (weaker) the current. Having numerous feeders ensures the current strength is high enough to power. Even if you had a 100' foot main line run with one solid piece of rail, the current would be less at the farthest end from the feed.
Soldering joints helps the electrical current pass throughout with a solid joint instead of a loose one which could break the electrical contact.
Inspired by Addiction
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I drop feeders every 6 feet, but I also solder all of the flex track curves, and I add feeders to every leg of every turnout, double crossover, double slip, 3 way, and wye.
Rich
Alton Junction
I've been soldering every other pair of flex track sections, so I have a 6 foor unit, then a non-soldered joint, then another 6 foot unit, at least where applicable. But I put feeds to all the joiners, both the soldered to the track one and the others.
Since DCC is a square wave AC< it's properly called 'phase' and not polarity, but it DOES matter. The same feed has to be on the same rail all the way around. Cross one over and you have a short. See my first post, about using 2 different color wires, and using a scheme you cna remember, such as my Red to the Rear.
Connecting back to the command station - not this again. My track is a complete loop, and not gapped. It really makes no difference. It would be kind of silly on a linear layout to run EXTRA wires back to the command station, but on a looped layout, the whole thing loops back anyway. Connecting the two free ends of a looped bus to the command station is electrically the same as closing the loop and connecting a pair of jumpers fromt he command station to the looped bus. And NOT loopign the bus while the track it is connected to forms a closed loop - well, that's the same thign too.
WHere you CANNOT loop things is the control or throttle bus. At least with most systems, these are a linear tree sort of arrangment and should never loop back on themselves or to the command station
Hi,
I finished the wiring of a two level 11x15 HO layout two years ago, my first go at DCC. Feeders are placed no more than 4 feet apart - and also on every track siding, irregardless of how long.
The thing is, whether DC or DCC, you never hear someone complain that they put in too many feeders. But, I've often heard folks say, I wish I had put in more.
Said another way, putting in "extra" feeders is just no big deal, and it won't hurt anything - but it very well could make your RR a better performer.
ENJOY !
Mobilman44
Living in southeast Texas, formerly modeling the "postwar" Santa Fe and Illinois Central
No. Rails have a much higher resistance to electricity than wires. Your voltage drop will be remarkable over only a decent length run.
Take a look at the 1:1 railroads. LIRR, MNCR and NYCT all use third rails and have sub stations about every mile. Lines with overhead wires can space the substations out to about 5 miles each.
Rather than think in terms of distance between feeders think of the over-riding objective, which is to increase the reliability of the electrical continuity at the rails. The best thing you can do is to eliminate reliance on any press fit electrical connection, rail joiners being the obvious one. If you solder together the rail joiners of 2 or even 3, 3' sections of flex-track, then one pair of feeders would be fine for that 6' or 9' length. I don't like to solder the joiners for my turnouts/switches, so to avoid reliance on the press fit joiners will run a set of feeders from every switch. The result of this strategy is that I can trace every single section of track, via solder connections to my bus. Sometimes the feeders are feet apart, other times just a few inches.
Is this necessary? Is this overkill? Quite possibly yes, but one thing I can say for sure, I will never have to trouble shoot an intermittent connection that relies on friction, which may degrade over time due to corrosion, or ingress of fluid such as liquid white glue or matte medium, used for ballast.
Simon Modelling CB&Q and Wabash See my slowly evolving layout on my picturetrail site http://www.picturetrail.com/simontrains and our videos at http://www.youtube.com/user/MrCrispybake?feature=mhum
alloboardAren't feeders only used because of the joints? If the rails are soldered like welded prototypes are, then what's the need for feeders.
Normal lead/tin solder is also a horrible conductor of electricity. When I plan to solder I make certain there is a good electrical connection with the rail joiner between the rails before I apply the solder. That way the solder is only holding that good connection in place and not replacing it with a "lead wire" so to speak. I am not certain how well the new alloy solder conducts. One can spend the money and get silver solder too. Silver is a better conductor than copper.