PRR Chartiers Branch: Hazel Mine - Lighting

February 23, 2018

The diagram below shows a side profile/cross-section of my overall layout. The brown part represents the cabinets upon which the layout is placed. The green part is the layout (the modules). The blue parts make up the overhead lighting system, the topic of this page. The dimensions are in inches. The framework for the lighting just fits under the 8-foot ceiling of the room. I wanted it to be tall enough so that when I stand on a small step stool, I don't hit my head on the lighting system. I also made it stick out over the front of the layout somewhat (by 6 inches), so that it could light up the front edge of the layout, as well as the drawers in the cabinets below the layout. These lights are also used as the general lighting of the entire room. The top diagonal brace measures about 33 inches.
External Reference:
I am completely sold on using LEDs to light up everything, such as locomotives, cabooses, structures, and even the layout itself. The LED strips that are now available can be had in various brightnesses and color spectrums. I want a light-weight, easy-to-remove lighting system over my layout. After doing some research, I settled on the 7-foot aluminum frames you can buy at the local hardware store, used for repairing or making your own custom window screens for your home. These are very light, yet plenty sturdy, and cost around $4 each (in 2018).
The LEDs I have experimented with are documented in my LED Strip Lighting article. I simply trim the strip to the desired length (paying attention to the proper cut lines marked on the strip), and use an epoxy glue to attach them to the underside of the aluminum frame (don't rely on the glue that the removable backing strip has; it will wear off in about two or three weeks). The aluminum frame is actually handy as a heat dispenser, as these LEDs do get quite warm.
The aluminum frame is easily cut with a metal-cutting blade in a handsaw, or a powered saw, or a Dremel tool with a cut-off disc. I then drill holes into the frame pieces and install bolts and nuts to tie them together. I use a drill bit that is about the thickness of the main shaft of the bolt. That way I have to screw the bolt into the metal frame, but it keeps it from being loose and eventually coming undone. The triangular design of the frame pieces makes the overall system sturdy with no sagging, and yet the whole assembly is very light-weight. I used two bolts at the 90-degree intersection shown in this photo, so that the two main parts stay at that angle. The diagonal crossbrace is installed with only one bolt at each end. The wire to power the LEDs is routed into the vertical frame member.
In the back of the layout, at the bottom of the vertical frame member, I used two wood screws to attach the assembly to the layout. In my previous modular set-up I had used bolts and nuts to attach these to the layout, but it was a real pain to move the entire layout out and away from the cabinets underneath in order to get to the nut behind the module's frame. A wood screw works just as well (just make sure to pre-drill all the holes), and it is easy to remove without having to move the layout. There is a lip on the back of these modules, so I cut a slot into it, which helps to hold the frame in position. Simply removing those two screws allows me to remove the light frame.
The wiring is routed through the aluminum frame (takes a bit of patience), but it must exit before the screws, as the wire is hard, if not impossible, to get past the screw.

March 02, 2018

A terminal, or barrier strip is used to make it easier to connect LED wires to power supplies or between modules, without having to bring out the soldering iron when it is time to take the lighting frames down. There can be up to 4 vertical lighting frames per module (if I need and build them all), so I installed an 8-slot barrier strip at the end of the module. At the next module over, I installed a 4-slot barrier strip, merging two of the ones from the other module per pair. When I need to move the modules, all I have to do is remove these connecting pieces of wire (made from heavy-gauge house electrical wire).

March 03, 2018

For now, I have four overhead "arms" for providing LED lighting. It appears to be sufficient for my current needs, but I can add more over time. Mostly for my own notes, below is the spacing from the left edge of the layout (as viewed from the front of the layout), with the relative order of installation next to it as well as the watts needed to power that overhead arm:
  2" - #2, uses 21W.
12" - #7.
24" - #6.
34" - #3, uses 21W.
48" - #9.
60" - #4, uses 21W.
72" - #8.
84" - #5.
94" - #1, uses 6W.