Attaching dropper wires to a bus

[Metr0Land]

A lot of people seem to use those joiners which just clamp a dropper wire from the track to the bus underneath the board, without soldering at the bus end.  Are they called cupboard joiners?

 

I've been trying to find some online but maybe I'm searching the wrong places and/or using the worng name.

 

Can someone point me in the right direction please?

[Tricky Dicky]

They are called Scotchlok connectors being an IDC (Insulation Displacement Connector). Therein lies the problem with them, they are really only designed to link two wires of similar diam. With a little leeway on the actual diameters. If you have widely different diameters in the two wires being linked then the following problems can occur. Get one to suit the thickest wire and the blade that makes the connection inside may not adequately displace the insulation on the thinner wire, whereas get one to suit the thin wire and you may find the blade almost severs the thicker wire. You will get get a lot of varying opinion on them but on a personal level as someone who has worked in electronics for much of my professional life, I would not touch them!

 

Soldering is your most reliable method. Look at the DCC Concepts site, Richard Johnson has an interesting method of soldering droppers based on using automatic wire strippers to displace a section of insulation and three terminal tag strips. The finished result not only holds your bus wire securely below the baseboard but also whilst soldering you do not have wires flopping about.

 

Richard

[Crosland]

"Double run" or "tap" splices are available designed for thinner wires in the tap (i.e. the dropper to the rails).

[Phil Bullock]

I have used the Express models solderless bus kit - blade terminals on the ends of the droppers plug in to displacement connectors

 

Very satisfied all round and makes tracing faults easy - just unplug the droppers until the short disappears

 

Phil

[smokebox]

Also known as suitcase connectors

[BoD]

I take a short piece of the copper clad PCB sleeper used in point construction and drill the required number of holes in it.

It is an easy job to solder the bus wire into the holes at each end providing the continuous bus and then droppers into the other holes.

It may be just one other hole for one dropper or as many as needed - quite useful when you have a lot of droppers in close proximity. The PCB sleeper is then stuck on the underside of the board with a hot glue gun.

But then I've always done things differently.

[Ian Abel]

Well, here's a vote for "suitcase connectors".

 

I'm using them quite successfully, running a 14ga. bus and utilizing 18ga. droppers. Whilst NOT an electrical engineer etc., etc., I had three main criteria;

i) Easy of use, non-time consuming installation

ii) No desire to spend hours under the baseboard soldering and therefore burning various parts of my anatomy!

iii) Inexpensive and readily available option

 

All three criteria are easily met, at least in the US, with an extremely ready availability of the 3M Scotchlok product, which IS (contrary to often posted messages on various forums) available in dual-gauge varieties.

The 14ga-18ga. items are available via a number of sources here not the LEAST of which are countless eBay suppliers.

Example -> http://www.ebay.com/itm/371007345299?_trksid=p2055119.m1438.l2649&var=640189737888&ssPageName=STRK%3AMEBIDX%3AIT

These at $9 with free shipping result in my "per track section (two connectors)" cost at about 18 cents or about 12p and once I've soldered droppers to the underside of the track sections (my choice of location), drilled the appropriate holes and laid the section it takes about 5 seconds apiece to have a connection to the bus with a simple pair of crimpers/pliers!

 

I did check the UK eBay for listing and seems that MOST of these are available from US suppliers, but even then didn't seem too hard to obtain and still very cost effective.

[Metr0Land]

2-sized ones are available in the UK.  Thanks to this thread I've been doing some more digging and found these:

 

http://www.ebay.co.uk/itm/281616098165?_trksid=p2060353.m2749.l2649&var=580619929409&ssPageName=STRK%3AMEBIDX%3AIT

 

A trial pack arrived today so hopefully I can conduct a bench test next week, in advance of jumping into the actual layout building with both size 10's (other shoe standards are available in Europe and North America)

[Metr0Land]

Just a little update.  I tried a bench test just now.

 

First off, I used a couple of the connectors as shown in #8 above and zip, zilch, nada, as Tricky Dicky suggested might be the case.

 

So I did some proper soldering just to make sure that would go ok, and it did.

 

I decided to have a 2nd go at the solder-free connectors and this time it worked ok as a bench test.  It seemed as though the little guillotine blades inside didn't go fully down the first time round.

 

I'm mulling it over now.  I can of course do soldering everywhere, especially whilst the new layout is being built, but as the years advance like so many on here I don't want to be working underneath the baseboard any more than I have to with future expansions of the layout.  (The current design has a full design and a 'lite' version so I hopefully don't run out of mojo whilst building it ie I should get two circuits running in a reasonable length of time and then expand).

 

Am starting to think I'll have a mix of fully-soldered wiring where it matters, and get some practice on sections which are eg long sidings, so I get practice of both ways, and if the connectors don't work I can leave it and come back.

[Ian Abel]

I've found the "trick" if you want to call it that is to use the correct pair of adjustable pliers (unless you actually want to buy the proper tool!) so that the jaws are parallel when closed to exactly the width of the suitcase in its closed position.

That way the metal conductor blade fully contacts both wires, also be sure both wires are sitting in the appropriate channels, you can easily get a missed connection if the wires aren't properly lined up. I've managed a couple of half-arsed connections when tired/lazy, but all the remainder of mine - probably now installed a couple of hundred of these things - work just fine.

The method I use is;

i) place both wires in their correct channels

ii) press the connector closed with finger pressure around the plastic part - this holds the wires in place and will highlight any mis-alignment of the wire in channel

iii) use pliers to squeeze the guillotine conductor blade fully down until flush with the top of the connector body

iv) snap the cover closed

Another "tell-tale" that maybe you've not got the thing properly set up is if the cover won't snap closed...

 

I resisted the temptation to buy the proper tool originally, and whilst in retrospect it would be the best thing I'm sure in the long run, time I had a pair of pliers set and working correctly I just leave them that way and use them just for attaching connectors.

 

Once you get a rhythm going and get the feel for them, I find I can do a pair of droppers for a section in literally about 25-30 seconds.

[14Steve14]

The main thing in using the scotchlok style connectors is to ensure that you use the correct size connector for the wire you are using. The ones we supply come in two colours, red and blue. The red once fit wires with a copper core from 0.5mmsq up to 1.5mmsq. These will fit wires from 16/0.2 up to and above 32/0.2.  The blue ones fit from 0.75mm sq up to 2.0mm sq. Thats upwards of 24/0.2 up to something like electrical flex. The one definate thing is that they should not be used with solid core wires.

 

People do sometimes complain about these style connectors. If you can solder, or know someone who can, then solder. If you cant solder and have no other choice I say use them. We supply them in our DCC wiring kits and have had no complaints so far.

[michaelp]

_{Used them on layouts and automotive applications with no problems at all}

[LJB]

These connectors are ideal when you want to tap into a running wire. Provided the connector is the right size for both wires there should be no problem. They are designed to be used in very challenging environments and function well. But yes, do make sure that the blade is well and truly home - which you can test by whether the overclip holds. I can solder perfectly well, but I would choose these every time for under-board work. Metal-to-metal connections work fine provided they are well made.

[sjrixon]

Anyone recommended this?

 

 

Look at about 12mins..

[14Steve14]

I hope you are referring to the clips and not having all the bus wires the same colour. Those are similar style clips, but you then need the crimp on blade connector for the dropper wires. As with everything its personally up to you what you use, but do make sure that you buy the correct size connectors for the wire you are using.