N Gauge newbie lost in a sea of DC wiring ideas trying to model locations from my youth (1950-60s Crawley, Sx)

[mjfjo]

17 hours ago, Pete the Elaner said:

 

No, that is not what I meant.

When I lay the track, I would still use insulated rail joiners & create sections like I was wiring it DC, but connect them together below the board.

This may sound a bit backward but there are advantages:

It is easy to join 2 sections together if they are isolated at track level. If you need to split a section, this is a pain because you will need to lift track.

Faults are easier to troubleshoot because smaller sections are less complicated, but you get less issues anyway.

 

& possible extra benefits which are unlikely to apply to your layout at this time:

 

If you sell the layout or decide that you don't like DCC, you do not have to lift any track to do the conversion.

If you want extra features like block detection or asymmetric braking in the future, you can just make changes under the board to enable them.

The method is scaleable so if you find yourself at a club working on a layout, the method does not get any more complicated & if you need to break the sections up to provide more power, this can be done.

 

This will leave you with lots of droppers, but if you use 1 colour for all the inside rails & another for all the outside, you simply need to connect the same coloured wires together.

Thanks for that. So just to double check, you basically wire all track droppers together underneath but isolate the actual track into separate sections? Theoretically could I wire all three circuits as one large single circuit with no isolation (in DCC that is, not that i would plan to do this but it helps with my understanding) or is there an actual operational reason to still isolate each circuit?

Regards

Mike

[mjfjo]

On 01/04/2021 at 22:25, Dungrange said:

You have an outer circuit that doesn't seem to be connected to the rest of the layout.  In theory, all you need is two wires to that track circuit (DC or DCC).....

 

One comment on your track plan is that you don't seem to have anywhere to store the trains that you are not running - ie you don't have a fiddle yard.  That may be intentional, but without a fiddle yard, you're probably limited to having about three or four locomotives on the layout at the same time. 

I think in hindsight and with some of the comments mentioned I will be connecting the outer circuit in a couple of places to the rest of the layout.

As for fiddle yard I will probably add another siding or two and "hide" locos there as I do not envisage having more that three or four locos on the layout for the foreseeable future, largely due to finances!

Many Thanks

Mike

[mjfjo]

With regards to the DCC option I had originally done some limited research into equipment but for some reason I was put off DCC by the complexity, when to me it seems no more daunting than DC from a wiring point of view and from operational viewpoint not something I am to worried about mastering.

Then and now I am quite interested in the NCE Powercab as a reasonably priced (relatively) unit to run my fairly "simple" layout with three or for locos, any opinions anybody?

[ITG]

1 hour ago, mjfjo said:

Thanks for that. So just to double check, you basically wire all track droppers together underneath but isolate the actual track into separate sections? Theoretically could I wire all three circuits as one large single circuit with no isolation (in DCC that is, not that i would plan to do this but it helps with my understanding) or is there an actual operational reason to still isolate each circuit?

Regards

Mike

Yes, it all could be one big circuit., ie bus wire. 
Or you can separate the track into separate sections, maybe your three layout track circuits. But the real advantage of doing so is in fault finding, because if you can switch a section on/off, it may help to find shorts etc. But with DCC, I cannot see there is any real operational advantage to having separate sections. Think of DCC as driving each loco independently, as opposed to DC controlling the track.

You will wish to consider how to operate accessories, which may be limited to points, ie

1. manual - self explanatory, either direct or via rods etc

2. DC - via a separate power source with switches driving point motors, either in a bank or on a layout mimic panel

3. DCC using the numbered buttons on your chosen handset, with each point being allocated an address number. This means in effect same point motors as in 2 above, but with either individual or banks of decoders to identify them. (But powered by your DCC source).

4. DCC using additional equipment, such as separate switches, which again could be a bank or panel, or via a laptop/tablet etc.

 

in my opinion, 3 is simplest, but I found continually moving from loco function to accessory function annoying, but this of course is very dependant on how many locos/points, ie layout complexity. So I then moved to a control panel (ie option 4) in which LED switches have same address code as points, and thus drive the point operation. But this is additional expense. Nothing to stop you doing that later if you opt to begin with option 3. Wiring is identical, apart from just 2 extra wires (in total) to said control panel.

Edited April 3, 2021 by ITG
Added

[mjfjo]

There seems to be a consensus on having lots of dropper wires from the track onto the power bus, does this also include having separate droppers from each point (I have insulfrog points) as well as from each section of "normal" track?

Also I am using thin Hattons multistrand wire (18 strand 1mm outside diameter) for the droppers, but I assume something thicker would be required for the power bus?

Thanks

[ITG]

1 hour ago, mjfjo said:

There seems to be a consensus on having lots of dropper wires from the track onto the power bus, does this also include having separate droppers from each point (I have insulfrog points) as well as from each section of "normal" track?

Also I am using thin Hattons multistrand wire (18 strand 1mm outside diameter) for the droppers, but I assume something thicker would be required for the power bus?

Thanks

More droppers equals more reliability, although there’s always folk who are more than satisfied with fewer droppers. As for points, well, I guess it depends on whether you wish to take a risk with a rail joiner becoming sloppy, and thus losing good contact. Not really any definite right or wrong.

Yes to thicker wire for bus, some folk prefer twisted wire (eg DCC Concepts sell it). Others use mains wire. Within reason, thicker means less resistance. See this link https://dccwiki.com/Wire_Sizes_and_Spacing

 

PS. Some  folk opt for a separate bus for accessories/points, again, good for trouble shooting. But not essential.

Edited April 3, 2021 by ITG

[Chimer]

Regarding linking in the third circuit, I offer three possible junction formations.  As you've said, you'll want two junctions rather than one, the second one needing to be a mirror image of one of the options.  Consider them as schematic and ignore the dimensions, my track planning software is set up for 00 .....

 

The top one is the simplest and probably least prototypical.  I would only use this one in a fiddle yard situation

 

The next one uses a simple diamond crossing.  The space marked with an A might be tighter, or more stretched out - in a station situation, for example, you could have an island platform in that gap.

 

The last one uses a slip and is the most space-efficient.  Probably a single slip, but in this orientation it could be a double slip which then also gives you a trailing crossover.  In a mirror image, the crossover would be facing, so not a good idea as previously mentioned.

 

Hope this might be of some use to you ...

[KingEdwardII]

55 minutes ago, mjfjo said:

I assume something thicker would be required for the power bus

I use 2.5mm2 mains FLEX for the power bus - perhaps a bit over the top, but relatively cheap and easy to use and of course, low resistance and thus minimal voltage drop. For a smaller layout, perhaps 1.5mm2 mains flex would be sufficient. I have an accessory bus and I use 1.0mm2 flex for that, since the current draw is much less. I am now also planning a 1.0mm2 pair for the 5V DC supply that my servo motor controllers are going to require for powering semaphores.

 

The reason for using mains flex - it's flexible (!! - stranded wires), widely available and you can get it at low cost. You can choose to keep the 2 or 3 wires together in one cable (I do this for point motors that have 3 terminals) or strip off the outer sheath and use the inner wires separately (I do this for the power bus, to assist with the frequent connections required for all the droppers). The inner wires are also natually colour coded which helps.

 

Yours, Mike.

[Dungrange]

I appreciate the potential change in direction from DC to DCC, but it's perhaps worth highlighting that if you intend buying locomotives that are not DCC Fitted and plan on fitting decoders yourself, the best advice would be to test the locomotive on DC before fitting a decoder, so if it doesn't work you know whether the issue is with the locomotive or the decoder.  As such, you may wish to keep one of your DC controllers, probably the Combi, so that you can test on a DC set up.  You certainly don't want to sell everything you've bought and then end up wishing you had a DC controller for testing purposes (although there is always a 9 volt battery!).

 

As for the choice of DCC Command Station, I've read lots of positive comments about the NCE Powercab and if you only plan on having two or three locomotives running at a time, I'd think the starter set should be adequate for your needs.  However, I think the principal deciding factor is the user interface and how easy you would find it to do everything that you want to do.  What attracted me to DCC is DCC Sound and lights: I model the post-privatisation era.  Therefore my choice of Command Station (the Sig-na-Track ACE2) was influenced by ease of access to the higher functions.  I didn't like those that involved multiple button presses to access F28: the Sig-na-Track ACE2 gives me all functions on a single touch screen and I can rename them.  However, a predominantly steam era layout may have little need for the higher numbered functions, in which case it's important to decide whether you want something that has a knob, a slider or a touch screen and whether you want something that is fixed or handheld.  It would be good if you could physically hold the NCE unit in your hand to decide whether you would find it comfortable to operate.

 

The other consideration is operation of the points.  As has been highlighted earlier, these can be operated manually; as a separate DC system; or be part of the DCC set up.  If part of the DCC set up, then you can either operate these from the Command Station, or by creating a panel (either switches or a touch screen).  Obviously operating the points from the DCC Command Station would be the cheaper option, but if that is the one you want to take, then it's important that you choose a DCC Command Station where the operation of accessories is straightforward.  However, if you're choosing either manual or panel operation, then how you would access the accessories on the Command Station is largely irrelevant.

 

I won't say that I think a switch from DC to DCC is the wrong move, but since you've said that funds are limited, I think it's important to consider the higher cost of DCC, particularly if you want to operate the points using DCC, as you'll need an accessory decoder for each point or crossover in addition to the need to fit decoders into all locomotives.  Make sure that you cost everything that you need before making a final decision to switch over to DCC.  There will be a learning curve whichever way you jump.

[mjfjo]

Many thanks for these latest replies, more food for thought and I will certainly look at the Sig-na-Track ACE2, I had visited the CoastalDCC site and lots of interesting stuff! Also I take the point about keeping the Combi controller, I was thinking that myself, also because I am quite taken with some of the small diorama style layouts I see in the mags and online and could envisage using the Combi if I make one of those with maybe a small DC shunter.

I have made a restart on the track laying, which entailed taking up a few sections of track and fitting droppers but I am still a bit confused as to whether it is necessary/advisable to use insulated rail joiners in any of the points areas. I am using insulfrog points and leaning towards it being a DCC operation.

Also does anybody have any views on using "suitcase" joiner clips on the bus connections, seem some positive and negative comments on these?

Regards

Mike

[Dungrange]

47 minutes ago, mjfjo said:

Also does anybody have any views on using "suitcase" joiner clips on the bus connections, seem some positive and negative comments on these?

 

Personally, I've never used them, and I've seen both positive and negative comments, but some people on here whose advice I trust (despite having never met them) highlight the importance of using the correct joiner for the size of wire that you are using - I think they are all colour coded.  If the diameter of your wire is less than the connector is designed for, then it won't cut through the insulation properly.  Conversely, if the diameter of your wire is more than the connector is designed for, then it will cut through both the insulation and some of the strands of wire.  Therefore, I think some of the negative comments relate to people who have just bought one size of connector and use it with various wire sizes. The positive comments come from those who check the compatibility of their particular wire and connector combination.

 

For my own layout, I've chosen to go with Wago 221 connectors, which were highlighted by several people on here.  They come in 2-way, 3-way and 5-way variants. (https://www.screwfix.com/p/wago-221-413-32a-3-way-lever-connector-50-pack/2803R?tc=CT8&ds_kid=92700055281954475&ds_rl=1249401&gclid=CjwKCAjwx6WDBhBQEiwA_dP8rc-3vxyPtO9vnZWzxBS75MVoSQPpg_2rwt4ht4KMcTmSMbkZ_PYUtBoCOegQAvD_BwE&gclsrc=aw.ds)

 

Of course all of our club layouts just use soldered joints, but that depends on how good your soldering skills are.

[Chimer]

Insulfrog points don't need IRJs to prevent shorts the way electrofrogs do.  But if you don't go DCC, you must as a minimum isolate the 3 circuits from one another, so put IRJs on any crossovers between the two inner circuits, and on the diverging tracks of all points leading from either inner circuit to the outer one.

 

Another DC thought, now you're thinking of using lots of droppers (apologies if it's obvious) .....  if you have droppers from a siding track to the bus wires, without a switch in the way, you can no longer isolate a loco by sticking it into the siding and setting the point against it, which is probably what you were used to doing back in the day.  This is good for DCC, as all the bells, whistles and lights keep working, but a bit of a two-edged sword for DC.

[Dungrange]

1 hour ago, mjfjo said:

I have made a restart on the track laying, which entailed taking up a few sections of track and fitting droppers but I am still a bit confused as to whether it is necessary/advisable to use insulated rail joiners in any of the points areas. I am using insulfrog points and leaning towards it being a DCC operation.

 

I don't know if you've looked at Brian Lambert's website - https://www.brian-lambert.co.uk/Electrical_Page_1.html.

 

This appears to be written for those without much knowledge of electrical matters.  It starts with the basic oval of track and then works to two ovals, each with a separate DC controller, and then to two ovals with a crossover between them, and shows that insulated rail joiners are required to separate the two circuits.  Although I don't think this is required with DCC (because all of the track is powered from the same Command Station Booster), I'd advise that you add these in now unless you are certain you're now going DCC.

 

I'd say, if in doubt, put in an insulated rail joiner and if it's not required, then you can bypass it by connecting the dropper wires together.  For my own layout, for which I'm using DCC, I'm using quite a lot of insulated joiners because I'd like to have working track circuits for signalling and potentially partial automation at a later date, so my wiring won't be significantly less than if I'd just gone with DC.  It's much easier to add insulated joiners and droppers when laying the track, than it is to install them at a later date.

[KingEdwardII]

3 hours ago, mjfjo said:

"suitcase" joiner clips

If you mean Tap Splice connectors like these:

 

https://uk.rs-online.com/web/p/splice-connectors/0531352/

 

...then I have used them successfully with my bus wires.

 

You need to buy the correct size for your cables. I have multiple different sizes since I have a variety of wire sizes for different bus wires and for droppers.

 

They are great for bus wires in that you can attach them anywhere along the bus wires, you can add as many as you like and it is a simple job with a pair of pliers to connect them. You can't really remove them once attached, but the connection wire can simply be cut off - there is no need to remove the connector itself.

 

There are lots of alternatives. Some folk like the Wago connectors - but these have the characteristic that you have to terminate all the wires in the connector - you can't just attach to an existing length of wire as with the splice connectors. It's fine to do the terminations, but I think it is a bit of a faff if you need to insert extra connections into an existing bus wire.

 

Soldering droppers direct to the bus wires, I really would not recommend, although I know that many folks do this. It is OK if you can get the baseboards out and on their sides, but I would not recommend soldering underneath a baseboard that is fixed in place - messing with hot solder in that location is not a good recipe. It also has the downside that you have to expose a section of the bus wire to make the solder connection - the exposed sections should not be left exposed in my opinion due the possibility of shorts.

 

Yours,  Mike.

[mjfjo]

21 hours ago, KingEdwardII said:

If you mean Tap Splice connectors like these:

 

https://uk.rs-online.com/web/p/splice-connectors/0531352/

 

...then I have used them successfully with my bus wires.

 

You need to buy the correct size for your cables. I have multiple different sizes since I have a variety of wire sizes for different bus wires and for droppers.

 

They are great for bus wires in that you can attach them anywhere along the bus wires, you can add as many as you like and it is a simple job with a pair of pliers to connect them. You can't really remove them once attached, but the connection wire can simply be cut off - there is no need to remove the connector itself.

 

There are lots of alternatives. Some folk like the Wago connectors - but these have the characteristic that you have to terminate all the wires in the connector - you can't just attach to an existing length of wire as with the splice connectors. It's fine to do the terminations, but I think it is a bit of a faff if you need to insert extra connections into an existing bus wire.

 

Soldering droppers direct to the bus wires, I really would not recommend, although I know that many folks do this. It is OK if you can get the baseboards out and on their sides, but I would not recommend soldering underneath a baseboard that is fixed in place - messing with hot solder in that location is not a good recipe. It also has the downside that you have to expose a section of the bus wire to make the solder connection - the exposed sections should not be left exposed in my opinion due the possibility of shorts.

 

Yours,  Mike.

Thanks for this again very useful information. I have found a roll of twin and earth cable left over from house wiring which I assume I can use for the bus wires once stripped away from the insulation. This has a rating label 1.5mm solid core 18 amp which sounds plenty for the bus. However I am still unsure regarding the dropper wires. I have read loads of threads on here and elsewhere and lots of different terminology seems to have been used. I have bought a couple of 100m rolls (Expo brand red and black) from Hattons without much info other than a label saying 0.14mm2. I have used this for the first few droppers I have soldered on but now unsure if this is thick enough as it seems very thin although I believe it is 18 strand multicore.  Could anybody clarify on this. With the disparity in size between the 1.5mm bus and the very thin dropper wires I assume there wouldnt be a scotchlok/suitcase type connector which could marry the two different sizes so it may be I have to solder join?

Thanks

Mike

[Dungrange]

I assume that the Expo cable that you have is 18/0.1 (https://www.expotools.com/acatalog/A22020-10-METRE-ROLL-OF-RED-18-0.1mm-CABLE-A22020.html) - they also do 100 m rolls.  That means that is has 18 strands of wire, 0.1 mm in diameter and it appears to be rated at 1.5 Amps.  It's probably a bit thin if you're planning on going DCC, as most Command Stations are rated at more than 1.5 Amps, but then droppers are unlikely to be carrying the full current output of a DCC system under normal operation (although could briefly carry the full current output of the Command Station under a short circuit scenario).  Provided your droppers are all short (ie less than one foot) you may be okay, but a thicker wire would be preferable, even for dropper wires (mine will generally be 16/0.2).  I believe that 18/0.1 wire is equivalent to about 26 AWG (American Wire Gauge), so I don't think you'll find a Tap splice connector that will work with such fine wire in conjunction with a bus wire that is around 16 AWG.

 

I also note that you're planning on using a solid core wire for the bus.  Most people seem to prefer multicore cables for model railway wiring, because multicore wire is more flexible and less likely to be damaged.  If you break one strand in a wire with 32 or 50 strands, it won't make a lot of difference: if you break the only strand in a single core cable, it will no longer conduct.

[mjfjo]

11 hours ago, Dungrange said:

I assume that the Expo cable that you have is 18/0.1 (https://www.expotools.com/acatalog/A22020-10-METRE-ROLL-OF-RED-18-0.1mm-CABLE-A22020.html) - they also do 100 m rolls.  That means that is has 18 strands of wire, 0.1 mm in diameter and it appears to be rated at 1.5 Amps.  It's probably a bit thin if you're planning on going DCC, as most Command Stations are rated at more than 1.5 Amps, but then droppers are unlikely to be carrying the full current output of a DCC system under normal operation (although could briefly carry the full current output of the Command Station under a short circuit scenario).  Provided your droppers are all short (ie less than one foot) you may be okay, but a thicker wire would be preferable, even for dropper wires (mine will generally be 16/0.2).  I believe that 18/0.1 wire is equivalent to about 26 AWG (American Wire Gauge), so I don't think you'll find a Tap splice connector that will work with such fine wire in conjunction with a bus wire that is around 16 AWG.

 

I also note that you're planning on using a solid core wire for the bus.  Most people seem to prefer multicore cables for model railway wiring, because multicore wire is more flexible and less likely to be damaged.  If you break one strand in a wire with 32 or 50 strands, it won't make a lot of difference: if you break the only strand in a single core cable, it will no longer conduct.

Hello and thanks again David for more informative comment. I do actually have the 100m rolls of red and black 18/0.1mm wire, but now it looks from what you say as though this may not be the most suited for use as droppers.  Purchase in haste repent at leisure seems to be my motto at the moment!

As for the bus wire, I think I will go with this solid core as I already have a roll and it is so sturdy I cannot see it ever breaking, especially as the layout is permanently fixed. Also I did see in a YouTube video that to get over the thin dropper wire into suitcase connectors that they folded the end round a few times before inserting in the connector to achieve fixture and connectivity?

I have also been looking further into suitable controllers, although fairly academic at the moment as most seem to be out of stock! My preference is for one with an actual throttle knob rather than say touch screen and one that seems well reviewed and fulfils this brief is the Digitrax Zephyr, but like most others seems to be in big demand and oout of stock everywhere, but I will contact CoastalDCC and ask re lead times etc.

Regards

Mike

[KingEdwardII]

20 hours ago, mjfjo said:

disparity in size between the 1.5mm bus and the very thin dropper wires I assume there wouldnt be a scotchlok/suitcase type connector which could marry the two

OK, so my approach is a two-step one.

 

I have it mind to be able to remove any section of track, if necessary, with the least fuss. Not so easy once everything is ballasted, etc, but by no means impossible. So, for me, this means that the droppers must be detachable. Since they are soldered at the track end, that means some form of detachable connection under the baseboard.

 

What I do is to attach to the power bus with 1.0mm2 wires (using the tap splice connectors) and run those to terminal blocks. The droppers are then wired in to the other side of the terminal blocks - and of course, the dropper wires are a lot smaller than 1.0mm2. I usually connect 2 or 3 pairs of droppers to each set of terminal blocks, although this is by no means required and I have plenty of cases of 1:1 connections. Wago connectors could be used instead of terminal blocks. I found terminal blocks very cheap and I like that they have a simple means to screw in place under the baseboard.

 

Here is an example from my layout:

 

 

The 1.0mm2 feed wires from the power bus are the blue and brown wires leading to the terminal block. In this case there are 3 droppers to the track and a pair linked to the point motor for frog polarity handling. The other wires relate to the point motor & the frogs.

 

The dropper wires are less than 1.0mm2, and need to be conveniently small for soldering to the track. 18/0.1 wire does sound a bit on the small side (~0.12mm2 or 26AWG): something more like 0.2mm2 (e.g.7/0.2 or 24AWG) would be my minimum - it has half the resistance of the 18/0.1 wire. Or even 0.3mm2 wire (e.g. 19/0.15). I happen to use dropper wire that is 12/0.2 = 0.4mm2 approx mainly because I had a reel of it lying around from some other project of mine. Its the Black-Black/White stuff in the picture.

 

BTW, wire sizing can be very confusing. I prefer to stick with the cross sectional area formulation (0.2mm2, etc) since it relates directly to the resistance. Stranding is a bit messy since wires of the same cross sectional area can have different numbers of strands of varying sizes. To see the wide variations take a look at the RS components website under "Hookup & Equipment wire" - they are not necessarily the best place to buy stuff, but they will show you the range of variations on offer. You can filter by cross section and by stranding.

 

This website is handy for converting between the wire formulas:

https://www.canford.co.uk/TechZone/Article/MetricAWGWireSizeEquivalents

 

Best wishes,

 

Yours, Mike.

[Dungrange]

1 hour ago, mjfjo said:

As for the bus wire, I think I will go with this solid core as I already have a roll and it is so sturdy I cannot see it ever breaking, especially as the layout is permanently fixed.

 

If it is a permanent layout, then you should be okay.  I think the cable you are intending using is the sort that an electrician uses to form a ring main and it then gets plastered into the wall, so never moves and therefore doesn't break.  Mains flex, the type used to connect a device to the wall (ie between the device and the plug), is normally multi-strand cable to cope with movement.  If you were building a layout that may be transported to an exhibition, or even just dismantled to allow a spare room to be used, I think the use of multi-strand cable would be better.  However, assuming your bus wire is fixed in place, I think that should be fine.

 

1 hour ago, mjfjo said:

Also I did see in a YouTube video that to get over the thin dropper wire into suitcase connectors that they folded the end round a few times before inserting in the connector to achieve fixture and connectivity?

 

I think that would be the only way that you could use Tap Slice connectors with your differing wire sizes.  I've also read people saying that they put multiple droppers into a single Tap Splice connector, which is effectively the same thing.  What I'm not sure of is whether those who adopt that approach are also the ones who end up making negative comments about the reliability of these connectors.  

 

Effectively, you'd need to get the right number of strands. https://www.canford.co.uk/TechZone/Article/MetricAWGWireSizeEquivalents indicates that AWG 26 is equivalent to about 19 strands of 0.1 mm diameter (19/0.1) - which is about the size of wire you have.  AWG 18 is equivalent to about 96 strands of 0.1 mm diameter (96/0.1), so you're probably looking at trying to get six of your 18/0.1 wires twisted / folded together to try and match up with the correct connector for your bus wire, which will be equivalent to around AWG 18 or AWG 16.

 

1 hour ago, mjfjo said:

I do actually have the 100m rolls of red and black 18/0.1mm wire, but now it looks from what you say as though this may not be the most suited for use as droppers.  Purchase in haste repent at leisure seems to be my motto at the moment!

 

I've got some of the same wire (albeit just the 10m loops) which I bought thinking 18 strands would be adequate and then realised that everyone else uses more robust wire.  I think the advantage of 18/0.1 wire is that it is very flexible, so would be useful for say wiring lights in buildings or similar situations where flexibility is more important than current draw.  I'm sure that I'll find a use for the wire at some point, but I'm not sure what.

 

From everything I've read on-line, I think 16/0.2 wire (equivalent to AWG 20) is probably the most suitable for droppers on a DCC layout.  However, there are plenty of people who use either 7/0.2 (equivalent to AWG 24) or 1/0.6 (ie a solid single strand wire of 0.6 mm diameter - equivalent to AWG 23) for droppers, but the key point is to keep them short to minimise the resistance and therefore voltage drop.  I've bought some 1/0.6 wire, as those who use this say they can make a neater solder join with single strand wire, so I will probably try this in the scenic part of my layout.  However, because I'm contemplating fitting train detection in my fiddle yard, I'll have plenty of droppers that will be six foot long, for which anything less than 16/0.2 isn't really appropriate.

 

I can't really say that you will have problems with 18/0.1 wire for your droppers, but I've never seen anyone advocate anything less than 7/0.2 (which is perfectly adequate for a DC layout - I've got several rolls of the stuff that I bought in the past).

 

1 hour ago, mjfjo said:

I have also been looking further into suitable controllers, although fairly academic at the moment as most seem to be out of stock! My preference is for one with an actual throttle knob rather than say touch screen and one that seems well reviewed and fulfils this brief is the Digitrax Zephyr, but like most others seems to be in big demand and out of stock everywhere, but I will contact Coastal DCC and ask re lead times etc.

 

I can't make any comment on the Digitax Zephyr, but I'm glad to hear that you at least know the type of control interface that you feel is best suited to your own preferences.  I'm sure that most DCC Command Stations are capable of doing what most users require, but some will be easier to use than others in certain situations.  It would therefore be worthwhile reading through the user manual to see how easy it is to do the things you want to do - change a locomotive address, switch between locomotives when you are driving three locomotives at once and change points etc.  Don't rush into the purchase.  Even if wiring the layout for DCC, if you place just one locomotive on your layout, you can still drive it with the DC controller you already have until such time as you are ready to part with the money.

Edited April 6, 2021 by Dungrange
typo

[mjfjo]

10 minutes ago, KingEdwardII said:

OK, so my approach is a two-step one.

 

I have it mind to be able to remove any section of track, if necessary, with the least fuss. Not so easy once everything is ballasted, etc, but by no means impossible. So, for me, this means that the droppers must be detachable. Since they are soldered at the track end, that means some form of detachable connection under the baseboard.

 

What I do is to attach to the power bus with 1.0mm2 wires (using the tap splice connectors) and run those to terminal blocks. The droppers are then wired in to the other side of the terminal blocks - and of course, the dropper wires are a lot smaller than 1.0mm2. I usually connect 2 or 3 pairs of droppers to each set of terminal blocks, although this is by no means required and I have plenty of cases of 1:1 connections. Wago connectors could be used instead of terminal blocks. I found terminal blocks very cheap and I like that they have a simple means to screw in place under the baseboard.

 

Here is an example from my layout:

 

 

The 1.0mm2 feed wires from the power bus are the blue and brown wires leading to the terminal block. In this case there are 3 droppers to the track and a pair linked to the point motor for frog polarity handling. The other wires relate to the point motor & the frogs.

 

Great stuff thanks for this, always helpful with a picture as well. My only question on this would be how do you run the blue/brown bus wires around to other locations, from terminal block to terminal block (presumably with more available terminals for in and out?)

Thanks

Mike

 

[mjfjo]

11 minutes ago, Dungrange said:

 

If it is a permanent layout, then you should be okay.  I think the cable you are intending using is the sort that an electrician uses to form a ring main and it then gets plastered into the wall, so never moves and therefore doesn't break.  Mains flex, the type used to connect a device to the wall (ie between the device and the plug), is normally multi-strand cable to cope with movement.  If you were building a layout that may be transported to an exhibition, or even just dismantled to allow a spare room to be used, I think the use of multi-strand cable would be better.  However, assuming your bus wire is fixed in place, I think that should be fine.

 

 

I think that would be the only way that you could use Tap Slice connectors with your differing wire sizes.  I've also read people saying that they put multiple droppers into a single Tap Splice connector, which is effectively the same thing.  What I'm not sure of is whether those who adopt that approach are also the ones who end up making negative comments about the reliability of these connectors.  

 

Effectively, you'd need to get the right number of strands. https://www.canford.co.uk/TechZone/Article/MetricAWGWireSizeEquivalents indicates that AWG 26 is equivalent to about 19 strands of 0.1 mm diameter (19/0.1) - which is about the size of wire you have.  AWG 18 is equivalent to about 96 strands of 0.1 mm diameter (96/0.1), so you're probably looking at trying to get six of your 18/0.1 wires twisted / folded together to try and match up with the correct connector for your bus wire, which will be equivalent to around AWG 18 or AWG 16.

 

 

I've got some of the same wire (albeit just the 10m loops) which I bought thinking 18 strands would be adequate and then realised that everyone else uses more robust wire.  I think the advantage of 18/0.1 wire is that it is very flexible, so would be useful for say wiring lights in buildings or similar situations where flexibility is more important than current draw.  I'm sure that I'll find a use for the wire at some point, but I'm not sure what.

 

From everything I've read on-line, I think 16/0.2 wire (equivalent to AWG 20) is probably the most suitable for droppers on a DCC layout.  However, there are plenty of people who use either 7/0.2 (equivalent to AWG 24) or 1/0.6 (ie a solid single strand wire of 0.6 mm diameter - equivalent to AWG 23) for droppers, but the key point is to keep them short to minimise the resistance and therefore voltage drop.  I've bought some 1/0.6 wire, as those who use this say they can make a neater solder join with single strand wire, so I will probably try this in the scenic part of my layout.  However, because I'm contemplating fitting train detection in my fiddle yard, I'll have plenty of droppers that will be six foot long, for which anything less than 16/0.2 isn't really appropriate.

 

I can't really say that you will have problems with 18/0.1 wire for your droppers, but I've never seen anyone advocate anything less than 7/0.2 (which is perfectly adequate for a DC layout - I've got several rolls of the stuff that I bought in the past).

 

 

I can't make any comment on the Digitax Zephyr, but I'm glad to hear that you at least know the type of control interface that you feel is best suited to your own preferences.  I'm sure that most DCC Command Stations are capable of doing what most user requires, but some will be easier to use than others in certain situations.  It would therefore be worthwhile reading through the user manual to see how easy it is to do the things you want to do - change a locomotive address, switch between locomotives when you are driving three locomotives at once and change points etc.  Don't rush into the purchase.  Even if wiring the layout for DCC, if you place just one locomotive on your layout, you can still drive it with the DC controller you already have until such time as you are ready to part with the money.

Thanks for your time again and very informative. I take your point re the dropper wire and also will retain for building wiring etc as you suggest. I do have a small amount of 16/0.2 20 AWG wire and hopefully keeping the droppers short should mean I can get by without needing too much more.

Will have a read through Digitrax user manual although I just viewed and very informative US youtube where he went through the basics very clearly and it looks a good system for me.

 

Thanks again.

Mike

[mjfjo]

22 minutes ago, KingEdwardII said:

OK, so my approach is a two-step one.

 

I have it mind to be able to remove any section of track, if necessary, with the least fuss. Not so easy once everything is ballasted, etc, but by no means impossible. So, for me, this means that the droppers must be detachable. Since they are soldered at the track end, that means some form of detachable connection under the baseboard.

 

What I do is to attach to the power bus with 1.0mm2 wires (using the tap splice connectors) and run those to terminal blocks. The droppers are then wired in to the other side of the terminal blocks - and of course, the dropper wires are a lot smaller than 1.0mm2. I usually connect 2 or 3 pairs of droppers to each set of terminal blocks, although this is by no means required and I have plenty of cases of 1:1 connections. Wago connectors could be used instead of terminal blocks. I found terminal blocks very cheap and I like that they have a simple means to screw in place under the baseboard.

 

Here is an example from my layout:

 

 

The 1.0mm2 feed wires from the power bus are the blue and brown wires leading to the terminal block. In this case there are 3 droppers to the track and a pair linked to the point motor for frog polarity handling. The other wires relate to the point motor & the frogs.

 

The dropper wires are less than 1.0mm2, and need to be conveniently small for soldering to the track. 18/0.1 wire does sound a bit on the small side (~0.12mm2 or 26AWG): something more like 0.2mm2 (e.g.7/0.2 or 24AWG) would be my minimum - it has half the resistance of the 18/0.1 wire. Or even 0.3mm2 wire (e.g. 19/0.15). I happen to use dropper wire that is 12/0.2 = 0.4mm2 approx mainly because I had a reel of it lying around from some other project of mine. Its the Black-Black/White stuff in the picture.

 

BTW, wire sizing can be very confusing. I prefer to stick with the cross sectional area formulation (0.2mm2, etc) since it relates directly to the resistance. Stranding is a bit messy since wires of the same cross sectional area can have different numbers of strands of varying sizes. To see the wide variations take a look at the RS components website under "Hookup & Equipment wire" - they are not necessarily the best place to buy stuff, but they will show you the range of variations on offer. You can filter by cross section and by stranding.

 

This website is handy for converting between the wire formulas:

https://www.canford.co.uk/TechZone/Article/MetricAWGWireSizeEquivalents

 

Best wishes,

 

Yours, Mike.

Ended up adding my original reply to this message on the bottom of your original! Meant to say I do have a bunch of terminal blocks so similar to yours I may go down this route, but to confirm it means daisy chaining the bus wire in/out of a number of terminal blocks to get all around the layout rather than just a single long run with droppers attached?

Thanks

Mike

[Dungrange]

1 minute ago, mjfjo said:

Meant to say I do have a bunch of terminal blocks so similar to yours I may go down this route, but to confirm it means daisy chaining the bus wire in/out of a number of terminal blocks to get all around the layout rather than just a single long run with droppers attached?

No, I don't think that's what @KingEdwardII is doing.  If I understand his post, he has a continuous bus wire of 1 mm2 cross section and then uses the appropriate tap splice connectors to create short spurs from the bus to a terminal block.  He uses the same wire for these spurs as he has used for the bus. The Tap splice connectors therefore contain two wires (the bus and the spur) which are of the same diameter, which is how these are intended to be used.

 

@KingEdwardII then connects the 1 mm2 spur from the bus into one side of a terminal block (as shown in his photograph) and connects all of the droppers in that area into the other side of the terminal block. 

 

Personally, I think this sounds a much better way of using tap splice connectors than trying to fold or combine droppers to try and get an equivalent wire size.

[KingEdwardII]

1 hour ago, mjfjo said:

but to confirm it means daisy chaining the bus wire in/out of a number of terminal blocks to get all around the layout rather than just a single long run with droppers attached?

No, I never daisy chain the wires coming off the power bus. I have lots of pairs of 1.0mm2 wires coming off the power bus, which each then connect to a single pair of terminal blocks.

 

The main power bus is indeed a "single long run around the layout" - or rather two long runs, since it is fed from the middle of the layout and there is a left section and a right section. The point of a large cross section power bus is to reduce voltage drop to a minimum and it gets more important to minimise voltage drop. a) as the length increases   and b) as the number of simultaneously active locos increases.

 

My power bus is about 5 meters for each half. I plan for 4 or 5 simultaneous locos, 1 or 2 manually driven the rest driven via computer automation.

 

Yours,  Mike.

 

PS You may find the solid core mains cable tough to work with. I always use mains flex, which is stranded and so much more flexible. Fairly easy to strip as well, when you need the wires separated out. Plus, when you need 3 wires (e.g. point motors) the earth is also a sheathed colour coded wire.

[mjfjo]

7 minutes ago, KingEdwardII said:

No, I never daisy chain the wires coming off the power bus. I have lots of pairs of 1.0mm2 wires coming off the power bus, which each then connect to a single pair of terminal blocks.

 

The main power bus is indeed a "single long run around the layout" - or rather two long runs, since it is fed from the middle of the layout and there is a left section and a right section. The point of a large cross section power bus is to reduce voltage drop to a minimum and it gets more important to minimise voltage drop. a) as the length increases   and b) as the number of simultaneously active locos increases.

 

My power bus is about 5 meters for each half. I plan for 4 or 5 simultaneous locos, 1 or 2 manually driven the rest driven via computer automation.

 

Yours,  Mike.

 

PS You may find the solid core mains cable tough to work with. I always use mains flex, which is stranded and so much more flexible. Fairly easy to strip as well, when you need the wires separated out. Plus, when you need 3 wires (e.g. point motors) the earth is also a sheathed colour coded wire.

Thanks for confirmation Mike, I think I get it now. My bus runs would be just over 2 metres each side.

I have stripped out the red/black from my 1.5mm solid core and think it would be ok generally but have just thought that maybe you cannot use those suitcase style connectors with moderately thick solid core, would it not be impossible to clamp down the metal joiner into this? If that is indeed the case I will need to go with the multistrand!

Regards

Mike