Model Railway Forum

That is the one I will be using. Good idea to have them above the baseboard and covered by a building. I’ll pinch that. R-

I like Brians Idea using a wire loop. Simple easy and free. And easy to remove one of the wires if you need to.
And if done neatly looks OK as well. You can also bring it above the BB and hide under a building. Not that I am bothered about nice pretty wiring after all your not knitting a jumper.

I was trained to de extremely neat wiring. On my last layout I decided to take my time so the wiring was a work of art. Started well, now looks like an explosion in a telephone exchange.

Me to WTD. You made me laugh on this cold horrible morning thanks.

My pleasure

On a DCC layout screw terminal connectors are not your friend. They're fine on DC but as I will explain, can lead to future issues on DCC layouts. They will work and for a while may not cause you any problems so I'm not suggesting that you get back under your board and rip them all out. However, if you experience DCC signal reliability issues in the future this might be something that needs a bit of attention.

Ok, so the premise for good reliable dcc wiring is to minimise the impendance of the dcc bus wiring. This is the main reason why you will see it reccomended that you use 2.5mm sq copper cable. It has little to do with the current carrying capacity of the cable but everything to do with a low inpedance circuit that can cope well with the complex square wave pattern of the dcc signal and the transient voltages that inevitably occur. The ideal scenario is not having any joins at all in your bus wires. Keep them continuous and solder on droppers where required. In practice of course that may not always be possible. The obvious example being on a modular layout where the bus needs to be joined each time the modules are put together. The simple answer to why it's better not to use screw terminals is that they cause an increase impedance. Therefore, using a lot of screw terminal joints can have a significant detrimental effect upon the quality of your dcc signal. The reason for this is that a screw down connection will become looser after a while. The copper strands squash down and there is less tension in the joint and the electrical continuity resistance increases. As the copper strands have more room to breathe the copper will oxidise which will further increase the resistance. Over time that resistance increases; multiply that by the number of joints and eventually you have a bus with significantly higher impedance than you started with. This will affect how the dcc signal copes with transient voltages (spikes) and you may start to see this causing problems.

So, what can you do instead to minimise this problem. Firstly, only ever consider using 2.5mm sq copper cable, nothing smaller. Second, if you need to have joins in your bus, i.e. for modular boards, use something like Wago connectors which will keep a constant tension/pressure on your cable join even as the twisted copper compresses. Don't ever cut your bus wires to insert terminals for connecting droppers. If you really aren't confident soldering joins then consider using something like T-Tap connectors. If you aren't familiar with Wago and T-Tap connectors just search for them on Amazon and you'll get lots of hits. I particularly like the Wago 221 type connectors.

I appreciate that none of this is probably much help if you've spent hours under your board cutting the bus and inserting screw terminals and it would be unrealistic to suggest you start again, especially if you've used 2.5mm cable and uour layout isn't huge. What you can do is go back periodically and check that all the screw down connections are tight. If you start to have any dcc signal problems at some point in the future then it may be that you need to take a look at whether you start replacing the connectors and renewing the bus.

I think that is a bit over the top for a general smallish layout. I am happy to be proved wrong.

I’ve used Wago 221 connectors and whilst they are, in my humble non technical experience, very good you do need a lot of them. The screw type connector has many advantages in connection capacity and if the screws loosen just tighten them again. R-

Personally, I avoid mechanical joints, preferring to solder droppers to the bus wires in every situation. You can’t argue that anything is better than a solidly soldered connection between every piece of track and the bus wires - effectively making the track, droppers and bus a single continuous piece of metal
I have a modular layout and employ D-sub connectors (soldered) to jump from board to board.
Having said that, I do appreciate that some modellers find soldering under the boards troublesome, consequently mechanical connectors are used. Providing the user accepts that they may fail at some point then fine.

However all my points, lights and servo circuits use mechanical (screw) joints because they are more likely to require the ability to disassemble components for maintenance. And some of that is quite frequent.

I think it is possible to put people off all together if mechanical joints are said to be a bad idea. Not everybody wants to solder. I quite enjoy it, but then again I also enjoy ballasting.