Using multiple colour wires for block detection - how have you done it?

[ITG]

Whilst I can/will work this out when I need to do this job, I’m just thinking ahead, not least so I buy the right quantities of the right colours. And thus wondered how others may have done this.

Here’s what I need to achieve.

The layout is some 5m x 2.4m, and a fairly complex track plan. I will be running iTrain and a Z21, with current sensing block detection. At a quick calculation, there could be some 80-100 feedback sensors, linked to either 5 or 6 DIgikejis or Yamorc 16 channel feedback modules (FM). Now obviously, there aren’t 80-100 different colours, but the size of the layout and spread of sensors means I probably only need 16 colours, ie a batch of the 16 feeding each FM. So with, say, 6 FMs equally distanced around the internal perimeter of the 600-700mm deep round-room board, there could be gaps of 1-2 metres between FMs, with the resultant length of wire between rail and FM.

So I’m thinking that each feedback (or multi if more than one in a block) uses dropper wires of a specific colour, which runs back to the FM, and then the DCC bus feed from Z21 to the FM is standardised as red. But that means (most of) these dropper wires will be longer than the customary straightforward DCC dropper. But if I use the heavier typical bus wire (32/0.2) as these droppers, will that be unsightly or ungainly where it’s soldered to the rail? If I mixed the wires, by using the normal dropper wire and then connecting it below baseboard to the coloured bus wire (and thus on to the FM), then isn’t that an (almost) unnecessary extra connection failure risk?

 

Any guidance or suggestions from past experience most welcome.

Ian

 

[InTheTrainShed]

I am NOT an expert but someone just starting out. This is how I handled it on my tiny test board - and I might do something like this on my real layout when I get to it.
 

I used white wire insulation and then marked bands using a sharpie pen - in this example I used a wide band to denote 5 , but if I did it again I might use a black band for a 5 then red and singles up to five …
 

Not suggesting anyone should follow this idea but it did work well for me.

[ITG]

1 minute ago, InTheTrainShed said:

I am NOT an expert but someone just starting out. This is how I handled it on my tiny test board - and I might do something like this on my real layout when I get to it.
 

I used white wire insulation and then marked bands using a sharpie pen - in this example I used a wide band to denote 5 , but if I did it again I might use a black band for a 5 then red and singles up to five …
 

Not suggesting anyone should follow this idea but it did work well for me.

Good idea, but the question of what gauge of wire is used where still exists. Dropper gauge or bus wire gauge all the way back to the feedback module, or did you have a join somewhere between dropper gauge and bus gauge?

By the looks of your photo, that wire seems fairly thick, so may be bus wire gauge all the way between track and module?

ian

[InTheTrainShed]

That picture might be misleading as it is TT:120 track at 12mm gauge. 

The wire I used there was 7 x .20 BUT please don’t take that as a recommendation as I am not qualified in any way to do so - I am still learning.
 

My test oval ran just a single TT loco so very little current being used and my longest run back to the Yamorc feedback unit was around 4 feet long

 

EDIT - my thinking was that I only had to worry about enough ‘power’ down those wires to handle the section / block I was linked to which by definition would only have one loco on it at any one time ?

Edited April 6, 2023 by InTheTrainShed

[WIMorrison]

Use something like 16/02 wire to connect to the feedback decoder from the track. If you use thinner wire then you run the risk of voltage drop, and also you can get crossover feedback that will show false occupancy

[Nigelcliffe]

The sharpie bands are a good idea.   There are lots of variations on it which are possible, and a simple code is enough to identify what is going on. 

I note ITTS is using ferrules on the wires into the screw terminals - good!  They make life a lot easier all round.  No chance of stray connection strands, go in/out cleanly, and electrically solid connection.  

 

On the droppers, I'd use a thin wire onto the rails for short pieces.  And an in-line joint to fatter wire for the longer runs to devices.  That could be a soldered connection (heatshrink over it when done), or more ferrules and screw-blocks.     The issue with wire is voltage drop over the length of wire.  For a short piece, a thin dropper has negligible voltage drop, but over longer runs it becomes significant, hence swapping to fatter wire.  

 

 

[Steven B]

If you want something more permanent than a band of Sharpie ink, then have a look at cable markers

e.g. https://www.ebay.co.uk/itm/394091280398?chn=ps&mkevt=1&mkcid=28

(not a recommendation, I've never used that seller!)

 

Using these you can number your feeds as required (at both ends if needed) . 

 

Don't forget that you can still use fine wire droppers, and solder on a larger diameter wire which can then feed the block detection. As some blocks may have multiple track feeds you may find yourself doing this regardless.

 

Steven B 

[ITG]

Thanks all, some good and varied approaches. Another planning box ticked.