Handrails

[hoppercar]

Installing the handrails on my locomotive...it's pretty thin wall, about .015 to .018 wall I believe......tubing is 3/16ths diameter....am I'm planning on running my lights wiring thru it. Using those superscale electrical junction boxes......the tubing is to thin to thread......how do you attach the tubing to the boxes ?...I'm thinking high strength loctite

[NP317]

LocTite works, as does epoxy. I've used both.
If you choose to use 3/16th tubing with thicker walls, just use the tubing as the negative conductor, soldering the wires on each end.
Then the narrow interior only has one wire inside.
RussN

[Soot n' Cinders]

LocTite works, as does epoxy. I've used both.
If you choose to use 3/16th tubing with thicker walls, just use the tubing as the negative conductor, soldering the wires on each end.
Then the narrow interior only has one wire inside.
RussN

This is what I have. Single positive conductor with the frame for ground.

[amadlinger]

I have soldered the junction boxes onto the handrails for robustness and for electrical connectivity, as I too have also always used the locomotive for ground and PTFE-insulated wire for the conductors.

This brings up an interesting question: do folks have a preference for the ground being negative, or positive? Negative ground is obviously the current automotive standard (although positive ground used to be common as well).

I have always used negative ground because that's the convention, but I have a 12VDC PWM dimmer switch that I would love to use on my loco, but it works best for positive ground scenarios.

[makinsmoke]

Some railroads like the Santa Fe had the conduit u-bolted to the handrail. SP too I think.

You can build it all on the workbench then install the larger assemblies onto the handrails and wire them up.

[jscarmozza]

Way back many vehicles had positive ground systems, sometime in the late 50's the US auto industry standardized on negative ground. Positive ground is supposed to cause galvanic corrosion of the vehicle body while negative ground corrodes the electrical components, I don't know if that is really a practical concern. I think the natural earth ground is negative, so I don't know if running a positive ground locomotive on metal tracks is contact with the earth is a problem? But more importantly, I'm encouraged to hear that frame grounding is effective, a two wire circuit on a 1" locomotive looks bulky and disproportionate, I'm going to re-wire the engine that I just finished wiring to a frame grounded system, there are always timely subjects on Chaski!

[kcameron]

At least using today's choice of LED's need a lot less current than the old bulbs. Yes color and other features need to be carefully looked at to make the right choices. But that lower current means smaller wires can do the job that required larger wires in the past. That in turn means smaller tubes that look right might be all the space needed for wires today.