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Offline MtrackJai  
#1 Posted : 07 December 2020 18:10:25(UTC)
MtrackJai

Canada   
Joined: 09/11/2020(UTC)
Posts: 45
Location: Saskatchewan, Regina
Greetings all,

I have seen here a breakdown of how often a person should use a feeder track. I thought it was every 2 meter on the straights and every 1 meter on inclines. Is this correct?

It seems like a bit of an overkill but I want to make sure that I don't have any slow areas.

I tried searching the forum but with almost 500 pages to go through I thought I would ask.

Thanks
Jai.
Offline H0  
#2 Posted : 07 December 2020 18:28:21(UTC)
H0


Joined: 16/02/2004(UTC)
Posts: 15,254
Location: DE-NW
Hi!

Some say every 1 m, some say ever 2 m, some say every 1.5 m. Some feed every track or every other track.

Before ballasting tracks, it's better to have too many than too few feeder wires.

For a temporary C track table layout, you can get away with one feeder every 20 m or even less. But this also depends on the trains you are using.
Regards
Tom
---
"In all of the gauges, we particularly emphasize a high level of quality, the best possible fidelity to the prototype, and absolute precision. You will see that in all of our products." (from Märklin New Items Brochure 2015, page 1) ROFLBTCUTS
UserPostedImage
Offline MtrackJai  
#3 Posted : 07 December 2020 18:30:09(UTC)
MtrackJai

Canada   
Joined: 09/11/2020(UTC)
Posts: 45
Location: Saskatchewan, Regina
I should clarify that I will be running M-track.
Offline H0  
#4 Posted : 07 December 2020 18:51:58(UTC)
H0


Joined: 16/02/2004(UTC)
Posts: 15,254
Location: DE-NW
In my experience conductivity is much better with C track than with M track.

For a permanent layout with M track I would use a feeder at least every 2 m, maybe more.
Regards
Tom
---
"In all of the gauges, we particularly emphasize a high level of quality, the best possible fidelity to the prototype, and absolute precision. You will see that in all of our products." (from Märklin New Items Brochure 2015, page 1) ROFLBTCUTS
UserPostedImage
Offline cookee_nz  
#5 Posted : 07 December 2020 18:56:04(UTC)
cookee_nz

New Zealand   
Joined: 31/12/2010(UTC)
Posts: 3,948
Location: Paremata, Wellington
Originally Posted by: MtrackJai Go to Quoted Post
I should clarify that I will be running M-track.


When you consider the length of each track section, every meter is going to have at least 5 track-joins.

Each join, no matter how firm is a resistance drop. Normal environmental influence of temperature variations means expansion and contraction which over time lead to a very slight loosening of joins and voltage drop.

If you are lucky enough to be starting with brand new track it will generally have nice tight joins, but if the joins were loose to begin with, this only aggravates the problem.

Personally I'd look at every 5 full sections, and more around turnouts etc. As others have pointed out, you can always simply leave them unconnected at first and if everything works, all good. If you have a soldering iron much cheaper and easier to make your own feeders than to use original feeder sections.

Hope this helps.

Cookee
Wellington
NZ image
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Offline MtrackJai  
#6 Posted : 07 December 2020 18:58:16(UTC)
MtrackJai

Canada   
Joined: 09/11/2020(UTC)
Posts: 45
Location: Saskatchewan, Regina
I purchased a soldering iron recently. I will try making my own. Do I need to worry about a resistor for noise?
Offline hxmiesa  
#7 Posted : 07 December 2020 19:02:56(UTC)
hxmiesa

Spain   
Joined: 15/12/2005(UTC)
Posts: 3,519
Location: Spain
I use K-track.
I use a feeder-wire for every 2 meters, BUT..: I "interleave" the connections with 1 meter;
red - 1m - brown - 1m - red - 1m - brown - etc.
I do this because SOME locos can show a slight lowering of speed in certain cases.

For inclines (both up AND down) I use different trafos with different speed-settings. In some cases I feed a downward incline from the same horizontal incline, but passing it through a set of anti-parallel diodes. (a voltage drop of around 0,7V) -I do this mostly on the hidden ramps, in order to save on the number of different trafos, which is already big.
There is no single good solution for this in analog running, as SOME locos will do an electronic regulation of its speed/load...
Best regards
Henrik Hoexbroe ("The Dane In Spain")
http://hoexbroe.tripod.com
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Offline JohnjeanB  
#8 Posted : 07 December 2020 19:19:58(UTC)
JohnjeanB

France   
Joined: 04/02/2011(UTC)
Posts: 3,084
Location: Paris, France
Hi
I agree with all the above but on a fixed layout, I suggest to insulate (on the B part-"Center rail") track sections (1 or 2 m) with only one feeder.
It may seem strange but later, when all the landscape is finished, looking for a short circuit becomes very difficult unless you have these insulated sections
This is especially important with M Track makes easy for any piece of metal to cause a short.
cheers
Jean
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Offline MtrackJai  
#9 Posted : 07 December 2020 19:24:12(UTC)
MtrackJai

Canada   
Joined: 09/11/2020(UTC)
Posts: 45
Location: Saskatchewan, Regina
Originally Posted by: JohnjeanB Go to Quoted Post
Hi
I agree with all the above but on a fixed layout, I suggest to insulate (on the B part-"Center rail") track sections (1 or 2 m) with only one feeder.
It may seem strange but later, when all the landscape is finished, looking for a short circuit becomes very difficult unless you have these insulated sections
This is especially important with M Track makes easy for any piece of metal to cause a short.
cheers
Jean


I had not thought of that. That is brilliant. I will look at doing that.

Offline Demch  
#10 Posted : 28 December 2020 22:18:30(UTC)
Demch

United States   
Joined: 10/03/2019(UTC)
Posts: 9
Location: Ohio, Strongsville
Hello, and Thank you to everyone that contributes to this forum I appreciate you all!!

I understand that some will add feeder wires to each and every piece of track and attach them to the Bus Wires so they can be assured to never have a power or ground issue. Is it possible that that much additional wire could cause problems?

If my layout is a permanent setup with 200 feet of K Track that is made up of several hundred pieces of individual track and every feeder wire is at least on average 8 inches long then I would be adding 200 *8 inches of wire that would be attached to the Bus Wires that are already quite long. That would be about 133 feet of awg22 feeder wires if it was done this way for both the Power and Earth wires. A total of 266 feet of wire in all just for feeders.

That seems like it could be a problem. Could that much wire actually become a negative and require Boosters just to help maintain a consistent and reliable current?

Am I overthinking this? I just want a layout that is electrically as perfect as I can get for the long run, and the hidden areas of my 4 tier setup do not cause nightmares for me 2 years from now.

Just a thought before I do a whole lot of soldering...
Thank you!!
Offline costing  
#11 Posted : 28 December 2020 23:53:55(UTC)
costing

Switzerland   
Joined: 20/08/2018(UTC)
Posts: 157
Location: Geneve, Geneva
The more feeder wires you have, the lower the resistance is. So electrically there is nothing wrong with having many of them. But this many... well, you'll be spending some time at the soldering station :)
JMRI on RPi & DCC++ / C-track / Marklin, Roco, ESU, Bemo locos / Christmas car collector
Offline DaleSchultz  
#12 Posted : 28 December 2020 23:54:37(UTC)
DaleSchultz

United States   
Joined: 10/02/2006(UTC)
Posts: 3,997
200*8 is overkill with K-track.

I also use K-track and I have made a lot of use of their 900mm long flex tracks so I typically feed every 1800mm, since two pieces can be fed with one feeder in the middle..

I also solder any track pieces together so no track current is reliant on friction fits of tracks together. See https://cabin-layout.mixmox.com/2005/07/laying-k-track.html for details on how I do that.

The path of the electrons from the power source to the locomotive and back to the power source is what matters, not all the additional feeder wires.
Most of the distance the power runs through the heavier bus wires and a larger number of feeders only helps.

Once you have got the hang of soldering the tracks together using the rail joiners and onto the underside of the track, you will find it is easy to make manageable 'chunks' of track up to 2m in size. Once laid and connected you should have no issues feeding sufficient current to the trains. No need to solder between this larger 'chunks' as each chunk have their own power feed.

Dale
Intellibox + own software, K-Track
My current layout: https://cabin-layout.mixmox.com
Arrival and Departure signs: https://remotesign.mixmox.com
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Offline perz  
#13 Posted : 25 January 2021 23:39:45(UTC)
perz

Sweden   
Joined: 12/01/2002(UTC)
Posts: 2,578
Location: Sweden
Originally Posted by: hxmiesa Go to Quoted Post
I use K-track.
I use a feeder-wire for every 2 meters, BUT..: I "interleave" the connections with 1 meter;
red - 1m - brown - 1m - red - 1m - brown - etc.


I would not recommend this kind of interleaving. One good practice to avoid electrical disturbances is to keep the feeder and return wire together. So therefore it is best to feed both red and brown at the same point, and to use a cable that contains a wire pair rather than having separate "red" and "brown" wires.

Regards
Per
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Offline phils2um  
#14 Posted : 26 January 2021 08:46:42(UTC)
phils2um

United States   
Joined: 12/01/2016(UTC)
Posts: 165
Location: Michigan, Ann Arbor
Originally Posted by: Demch Go to Quoted Post
Am I overthinking this?


No, you are not overthinking things! Your bus wires need to be a much heavier gauge to avoid significant voltage drop in 130 feet out and back! I'd use 16 awg at least for that length of bus run. Using 22 awg for the individual feeder drops off the bus is not a problem. The voltage drop in a couple of feet of 22 gauge wire is not an issue. (Figuring one foot out and one foot back from the bus wire to the track.)

copper wire resistance per foot: 16 awg - 0.00409 ohms/ft
22 awg - 0.0165 ohms/ft

Using Ohm's law, V=iR lets look at the voltage drop assuming you loco draws half an amp near the end of you line at 100ft bus + 1ft feeder. remember it's out and back so the lengths are doubled!

22 awg all the way: R = 202 x 0.0165 = 3.33 ohms and V = iR = 0.5 x 3.333 = 1.67 Volts

16 awg + 1ft 22 awg drop: R = (200 x 0.00409) + (2 x 0.0165) = 0.851 ohms and V = iR = 0.5 x 0.851 = 0.426 Volts

To keep it simple assume you are running analog at half throttle - about 8 Volts. The loco speed is proportional to the voltage at the motor. Right next to the transformer the loco sees 8 V and 100 feet down the 22 awg line it sees 6.33 V - a 21% speed drop!

100 feet down the 16 awg line the motor sees 7.574 V - only a 5.3% speed drop.

Also note that the more current you are drawing the greater the voltage drop!

Let us assume you loco is pulling a rake of lighted coaches and the current draw is now 1 amp. At half throttle the speed drop at 100 ft with a 22 awg bus is now 42%! With the 16 awg bus it is 11%
Phil S.
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Offline JohnjeanB  
#15 Posted : 26 January 2021 13:01:05(UTC)
JohnjeanB

France   
Joined: 04/02/2011(UTC)
Posts: 3,084
Location: Paris, France
Hi
What I have learnt messing around with my train is:
* install a power line (Ringleitung) with 2,5mm² to avoid voltage drops (my digital power is 100 W)
* distribute the power to track segments of max 2 m to avoid track voltage drops
* have theses segment insulated from each other to make it easy to locate a short circuit
* mark the insulation points either on the track (color-coded point) or on the drawing
* have a separate power distribution to decoders (switch decoders, etc) in case you want to run analogue trains and also to limit results of faulty switch decoder
Cheers
Jean
Offline hxmiesa  
#16 Posted : 26 January 2021 13:07:44(UTC)
hxmiesa

Spain   
Joined: 15/12/2005(UTC)
Posts: 3,519
Location: Spain
Originally Posted by: perz Go to Quoted Post
I would not recommend this kind of interleaving. One good practice to avoid electrical disturbances is to keep the feeder and return wire together. So therefore it is best to feed both red and brown at the same point, and to use a cable that contains a wire pair rather than having separate "red" and "brown" wires.r

Well, I dont know what to say to that.
It has worked (and works) very well after almost 15 years.
I run thick bus-wires ("loom") under the layout, with distribution points at intervals. I connect the feeder-wires to their nearest distribution point.

In my eperience the interleaving allows for less sensitivity to power-drops; On my analogue layout I see some difference in speed and performance depending on the distance to a feeder-point.

Out if curiosity, what kind of electrical diisturbance are you talking about?

Best regards
Henrik Hoexbroe ("The Dane In Spain")
http://hoexbroe.tripod.com
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Offline perz  
#17 Posted : 26 January 2021 19:15:00(UTC)
perz

Sweden   
Joined: 12/01/2002(UTC)
Posts: 2,578
Location: Sweden
Originally Posted by: hxmiesa Go to Quoted Post
Originally Posted by: perz Go to Quoted Post
I would not recommend this kind of interleaving. One good practice to avoid electrical disturbances is to keep the feeder and return wire together. So therefore it is best to feed both red and brown at the same point, and to use a cable that contains a wire pair rather than having separate "red" and "brown" wires.r

Well, I dont know what to say to that.
It has worked (and works) very well after almost 15 years.
I run thick bus-wires ("loom") under the layout, with distribution points at intervals. I connect the feeder-wires to their nearest distribution point.

In my eperience the interleaving allows for less sensitivity to power-drops; On my analogue layout I see some difference in speed and performance depending on the distance to a feeder-point.

Out if curiosity, what kind of electrical diisturbance are you talking about?



I wouldn't say it does not work, just that the risk for problems is higher. I think your bus wire approach somewhat mitigates that. Disturbances may occur on decoders in locos or turnouts, but more likely in other electronic equipment in the surrounding of the layout. The reason is that current in a wire causes an electromagnetic field. But if the feeder and the return wire are close the two fields cancel eachother.

Regards
Per Z.


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H0
Offline H0  
#18 Posted : 26 January 2021 19:47:05(UTC)
H0


Joined: 16/02/2004(UTC)
Posts: 15,254
Location: DE-NW
I think especially s88 feedback can be sensitive to electric disturbance. Interleaved feeders may turn out to be a problem when adding s88 at a later stage.
I don't know if mfx feedback is at risk.
Regards
Tom
---
"In all of the gauges, we particularly emphasize a high level of quality, the best possible fidelity to the prototype, and absolute precision. You will see that in all of our products." (from Märklin New Items Brochure 2015, page 1) ROFLBTCUTS
UserPostedImage
Offline perz  
#19 Posted : 26 January 2021 20:33:12(UTC)
perz

Sweden   
Joined: 12/01/2002(UTC)
Posts: 2,578
Location: Sweden
Originally Posted by: H0 Go to Quoted Post
I think especially s88 feedback can be sensitive to electric disturbance. Interleaved feeders may turn out to be a problem when adding s88 at a later stage.
I don't know if mfx feedback is at risk.


I haven't tested, but I think mfx feedback would not be so sensitive, because it measures the current at the controller. And in the controller, the feeder current and the return current are the same regardless of which paths the current takes on its way round.

However, if you use distributed current sensing, as we did on our company layout and I intend to do on my new layout, I imagine that there could be problems.

A side note: mfx feedback together with distributed current sensing could theoretically be used as a way to detect which train is where on the layout since mfx feedback is actually variation of the current. But there are drawbacks, mainly that it would have slow reaction time, so it is not a good idea in practice.

Regards
Per Z.
Offline scraigen  
#20 Posted : 27 January 2021 21:41:25(UTC)
scraigen


Joined: 29/01/2009(UTC)
Posts: 299
Location: Sheffield,
Originally Posted by: phils2um Go to Quoted Post
Originally Posted by: Demch Go to Quoted Post
Am I overthinking this?


No, you are not overthinking things! Your bus wires need to be a much heavier gauge to avoid significant voltage drop in 130 feet out and back! I'd use 16 awg at least for that length of bus run. Using 22 awg for the individual feeder drops off the bus is not a problem. The voltage drop in a couple of feet of 22 gauge wire is not an issue. (Figuring one foot out and one foot back from the bus wire to the track.)

copper wire resistance per foot: 16 awg - 0.00409 ohms/ft
22 awg - 0.0165 ohms/ft

Using Ohm's law, V=iR lets look at the voltage drop assuming you loco draws half an amp near the end of you line at 100ft bus + 1ft feeder. remember it's out and back so the lengths are doubled!

22 awg all the way: R = 202 x 0.0165 = 3.33 ohms and V = iR = 0.5 x 3.333 = 1.67 Volts

16 awg + 1ft 22 awg drop: R = (200 x 0.00409) + (2 x 0.0165) = 0.851 ohms and V = iR = 0.5 x 0.851 = 0.426 Volts

To keep it simple assume you are running analog at half throttle - about 8 Volts. The loco speed is proportional to the voltage at the motor. Right next to the transformer the loco sees 8 V and 100 feet down the 22 awg line it sees 6.33 V - a 21% speed drop!

100 feet down the 16 awg line the motor sees 7.574 V - only a 5.3% speed drop.

Also note that the more current you are drawing the greater the voltage drop!

Let us assume you loco is pulling a rake of lighted coaches and the current draw is now 1 amp. At half throttle the speed drop at 100 ft with a 22 awg bus is now 42%! With the 16 awg bus it is 11%


It’s not 130ft all the way in one long wire and then back again it’s 130ft of wiring in total across the whole layout. There’s a lot of over thinking going on here. The common recommendation is more feeders and grounds is good and a larger cable for bus wires. But be sensible if you start ending up with cables bigger than mains appliances you’re just making it hard work for yourself. Bear in mind how small the track box wires and wires from decoders to motors are. You need wire strong enough not to break when you accidentally yank it and small enough that you can work with and solder it with ease.
Must build something
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Offline hxmiesa  
#21 Posted : 27 January 2021 21:55:56(UTC)
hxmiesa

Spain   
Joined: 15/12/2005(UTC)
Posts: 3,519
Location: Spain
Originally Posted by: perz Go to Quoted Post
I wouldn't say it does not work, just that the risk for problems is higher. I think your bus wire approach somewhat mitigates that. Disturbances may occur on decoders in locos or turnouts, but more likely in other electronic equipment in the surrounding of the layout. The reason is that current in a wire causes an electromagnetic field. But if the feeder and the return wire are close the two fields cancel eachother.

Maybe if we were running on 1,5kV, there could be a disturbing field around a single wire... ;-)

In any case I doubt that it is an issue on my analogue AC layout. -Even if I do use 24Vdc on my track-feedbacks.
Instead of the flimsy MRR decoders I use industrial strength PLCs, -but I doubt my electrical system would disturb the fine electronics anyway; All 24Vdc track detection feedbacks runs through 2K Ohm resistors, so the current is very limited.

Best regards
Henrik Hoexbroe ("The Dane In Spain")
http://hoexbroe.tripod.com
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Offline Bigdaddynz  
#22 Posted : 27 January 2021 22:56:24(UTC)
Bigdaddynz

New Zealand   
Joined: 17/09/2006(UTC)
Posts: 18,661
Location: New Zealand
Originally Posted by: MtrackJai Go to Quoted Post
Do I need to worry about a resistor for noise?


Are you referring to the noise suppression capacitor that can be fitted to M track feeder tracks? The capacitors shouldn't be used if you have a digitally controlled layout as the capacitor will interfere with the digital signal.

Also, most modern day TV's, Radios, etc are built in such a way that they won't be affected by noisy model trains so you could probably get away with not needing to use a noise suppression capacitor with analog trains.
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Offline MtrackJai  
#23 Posted : 30 January 2021 23:36:36(UTC)
MtrackJai

Canada   
Joined: 09/11/2020(UTC)
Posts: 45
Location: Saskatchewan, Regina
So I am trying to solder to the M track. Any tips? I can't seem to get the brown wire to adhere to the bottom tin of the track.
Offline JohnjeanB  
#24 Posted : 31 January 2021 01:42:26(UTC)
JohnjeanB

France   
Joined: 04/02/2011(UTC)
Posts: 3,084
Location: Paris, France
Hi
"So I am trying to solder to the M track. Any tips?"
Soldering M tracks is not so difficult but:
* you need a good iron with thin tip and preferably regulated temperature
* you need to scratch the paint, under the rail at the clamping of the contact blade, near the plastic insulator. Then with a pre- tinned wire, apply solder (electronic grade) and process rapidly so to avoid melting the insulator
* soldering a (red) wire on the contact blade is easier: approach pre-tinned wire to the start of the contact blade and process rapidly.

Notes:
* if you don't succeed the first time, no problem: stop immediately and let the part cool down, clean the solder contact and repeat.
* The temperature is important: too low, the solder will not completely melt (you see crystals). Too high, then the tin goes away in little drops. I think the good one is around 220°C
* the solder contains a product (the flux) to facilitate the soldering but it burns rapidly (you see the smoke for a few seconds) and then the soldering becomes much more difficult. In this case, no problem, clean the tip of your iron and restart with a new piece of solder.
* never, ever file the tip of your iron as it would ruin the metal coating leaving the copper unprotected and subject to acid action
Cheers
Jean
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Offline phils2um  
#25 Posted : 31 January 2021 01:50:59(UTC)
phils2um

United States   
Joined: 12/01/2016(UTC)
Posts: 165
Location: Michigan, Ann Arbor
Originally Posted by: scraigen Go to Quoted Post
But be sensible if you start ending up with cables bigger than mains appliances you’re just making it hard work for yourself.


Yes, there can be overkill. That's why I suggested 16 awg for the bus in my example and not the 12 awg I use as a feeder to my garden railway! However, you need to think about the power being delivered at the (low) voltages we are working with. There is a reason the battery cables in your car (12V system) are as big as they are and not the size of the "mains" cable to your refrigerator compressor (110/220 V system). The example I gave illustrates exactly why short lengths of small cross-section wire is acceptable - the voltage drop is not of significance and the bulk of the power is going to the loco and not being consumed in heating the wire. (As long as the wire gauge isn't so small it acts as a fuseBlink)
Phil S.
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Offline MtrackJai  
#26 Posted : 01 February 2021 17:04:01(UTC)
MtrackJai

Canada   
Joined: 09/11/2020(UTC)
Posts: 45
Location: Saskatchewan, Regina
Originally Posted by: JohnjeanB Go to Quoted Post
Hi
"So I am trying to solder to the M track. Any tips?"
Soldering M tracks is not so difficult but:
* you need a good iron with thin tip and preferably regulated temperature
* you need to scratch the paint, under the rail at the clamping of the contact blade, near the plastic insulator. Then with a pre- tinned wire, apply solder (electronic grade) and process rapidly so to avoid melting the insulator
* soldering a (red) wire on the contact blade is easier: approach pre-tinned wire to the start of the contact blade and process rapidly.

Notes:
* if you don't succeed the first time, no problem: stop immediately and let the part cool down, clean the solder contact and repeat.
* The temperature is important: too low, the solder will not completely melt (you see crystals). Too high, then the tin goes away in little drops. I think the good one is around 220°C
* the solder contains a product (the flux) to facilitate the soldering but it burns rapidly (you see the smoke for a few seconds) and then the soldering becomes much more difficult. In this case, no problem, clean the tip of your iron and restart with a new piece of solder.
* never, ever file the tip of your iron as it would ruin the metal coating leaving the copper unprotected and subject to acid action
Cheers
Jean


Thank you for the tips. I will give this a try.
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