A frequent question I read is how to attach tin accessories, such as Marx light posts and light towers, to a layout in a semi-permanent but reversible manner. I have found a way to do this, and as a bonus, it also makes it easy to hide the wires that are feeding the lights and makes the wiring simpler.
The binding posts on Marx lights, it turns out, are nothing more than 8-32 machine screws that are around a half inch long. Remove the two nuts on the screw, then remove the screw, and take a longer 8-32 machine screw (perhaps an inch and a half long–long enough to reach through your table), then drive that machine screw through from the top, so the threads are now facing down rather than up. Replace the regular nut to hold the screw to the base of the accessory. Mark the position of the screws where you want the light to go, then drill two holes in your table 3/16 of an inch in size at those two marks. Now place the light through those holes.
On the underside of the table, you now have two binding posts protruding through. Attach your hot and ground wires from your transformer to those posts and secure them with the brass thumbscrew.
You can easily daisy chain your lights together this way–just run a pair of wires from one light to the next until you’ve wired all of your lights. Unlike trains, you don’t need very thick wire–20 or 22 gauge wire salvaged from old phone cords or network cables will work fine.
Make sure you run two wires to each light, rather than wiring them in series with just one wire. That way if one bulb burns out, you don’t lose all of them and have to go hunting for the single burned-out bulb. This is supposed to be fun.
If you have a fair number of these, or plan to have a fair number of them, consider buying a variety pack of 8-32 screws. The leftovers will make for a nice spare parts stash, and you’ll be raiding it more than you may think.
For power, I recommend using a separate transformer from your trains, keeping in mind miniature light bulbs use about .2 watts apiece, so even a 40-watt transformer from a starter set can power more than 60 lamp posts (assuming 60% efficiency). Here’s a look at the power requirements of Marx accessories.
I don’t worry about the scale, but if you’re curious, here’s some information on the scale of Marx accessories.