Atlas O SCALE TERMINAL JOINERS

Yes

You HAVE to use the ones with the dimples on the bottom. The early ones without are garbage and people still sell them as NOS on eBay. I recently dismantled my layout of 15 years and found I had a good number of the old ones mixed in and I'm certain that is where I had issues with non cruise locomotives slowing down.

I have them on my 6x12 layout with an inner loop and outer loop and have had no issues. Always use new rail joiners. They may not be as reliable when reusing them over time.

I made my own.

I took a piece of atlas track and screwed it down to the benchwork upside down with one end hanging off.  I put three rail joiners on to the ends of the rails, tinned the bottoms and the wire ends, and just touched the soldering gun and the wire to the joiners:  nearly instant.  Putting the joiners on the track holds them in place.  They cool quickly, and then I pulled them off and put three more on.  The work goes quickly.

The Atlas O Terminal Joiners are excellent.  I use them every 3 feet on my layout and at either side of switches.  I made my own by using the regular Nickel silver and Blackened Joiners and sanding the bottom with a Dremel Tool sanding drum before soldering a 36" length of wire.  (sanding makes the solder adhere better.)  All wires under my table go to MTH Terminal Boards that are daisy chained under the double mainline of the layout and back to the transformer. (Rail loop on top, and wire loop underneath with Terminal Joiner feeders to track.)

One shipment of Atlas O Rail Joiners switched the black and red wires. Make sure all outside Nickel Silver rail joiners have a black wire and center Blackened rail joiners have a red wire.  (Switching these colors could cause a short when joining wires under the table.)

See photo of Atlas O Terminal Joiners from two different manufacturing runs and the confusion it could cause when wiring under the layout table.  I re-soldered many of mine that I purchased or (painted the ends of some of the switched wires to indicate outside from center rail.)

Here is an alternate method to power Atlas track if you don't want to use the rail joiner terminals. Works great!

If you are interested the screws described are available from Micro-Fasteners.

OGR #16 wire works very well with this method too, that is what I used.