FloodSticks

FloodSticks are small RGB LED floods mounted inside PVC pipe so that the floods can be elevated above snow and hidden behind other props, thereby creating almost invisible light sources. The intention was to angle the light downward to illuminate a relatively small area, thus using the snow as part of the display. The notes here describe the experimental set of FloodSticks; there's no magic to the sizes and dimensions of the materials used. The FloodSticks performed exactly as intended as shown in this brief video: https://vimeo.com/196122980

Materials:

• PVC pipe (1" diam, thin-wall, 30" long, cut into two pieces, 21" and 9" long)
• PVC coupling (1" to 1/2" adapter, used for the stand-up strut)
• PVC coupling (45 degree)
• PVC pipe (1/2" diam, 8" long - used for the side, stand-up strut)
• Transparent fluorescent light protector tube (cut to fit/protect the LED)
• PVC or other end cap
• Pill bottle
• Zip ties
• 3-watt RGB LED
• 3, 1-watt resistors (LED current control)
• 2-1/2" to 3" length of 1" wide thin aluminum bar stock (LED heat sink)
• DIGWDF RenStick (an ESP-wireless, DC controller)
• 120vac to 5vdc buck converter, 1.5A or greater output (purchased on eBay)
• Wire, plugs, electrical tape, high-temperature and other glues, paint (optional)

Construction notes:

• The pill bottle was not originally planned, but the power bucks were too large to fit inside the 1" PVC. A future design would use 1-1/2" PVC instead, thus eliminating the pill bottle and zip ties.
• The PVC pieces were tightly press-fit instead of glued; this proved to work very well and allowed later access to the controller
• Mounting in the yard was simple: a stake was driven into the ground on an angle and the FloodStick simply slid down over it. The side, stand-up strut helps keep not only the angle but helps stabilize the FloodStick from movement by wind.
• The photos should be quite self-explanatory for assembly

The Controller is a wireless RenStick, using an ESP module for wireless communication. (RenStick is a 4-channel DC controller that uses high-powered transistors for outputs up to 2A. It's less than an inch across and was designed specifically for the FloodStick project.) After placing the FloodStick in the yard, some experimentation may be necessary to orienting the ESP's antenna for the best reception; simply pull the top section off, rotate the entire RenStick inside the PVC tube and reassemble the tube.

We originally thought at smaller, 700ma 5vdc buck converter would work, but we quickly discovered that the ESP module would disconnect from the network when all 3 colors were on because the ESP didn't get enough current. The larger 1.5A buck converter solved that problem but wouldn't fit inside the PVC tube. Our solution was to wrap a pill bottle in black tape and strap it onto the side of the strut, fitting the buck converter inside.

The buck converters were purchased via eBay -- there are many voltages and options available. It was eventually discovered that the operating temperatures of these devices can vary widely; when temperatures dropped to sub-zero, the FloodSticks became unresponsive, which we determined were likely due to buck converter failure since the ESP8266 modules themselves are spec'd down to -40C/-40F.

The LED was glued to the additional aluminum bar stock for not only additional heat dissipation but for ease of mounting in the PVC tube using more of the high-temp glue. 1-watt current-control resistors were soldered directly to the 3W LED and wires that extended down to the controller prior to glueing in the PVC tube. The high-temp glue was purchased at a local auto parts store. These RGB LEDs were rated at 350ma current with red rated at 2-2.5vdc and both green and blue rated at 3.2-3.8vdc. Had suitable 3.3vdc buck converters been available that could deliver enough current I would have preferred to use them instead of the 5vdc converters; the 3.3 would eliminate the need for the RenStick's voltage regulator and possibly the current control resistors.

Because the LEDs have a 120-degree viewing angle, a 120-180 degree window was cut into the top of the PVC tube using a Dremel tool. The size of the window was somewhat arbitrary -- we had no idea how large to make it but we were confident that if the need arose, we could easily mask the window with black electrical tape. A length of the protection tube for fluorescent lights was cut and slit in the back, allowing to slide it over the window; black tape was used to secure it for waterproofing.

We used 1" thin-wall PVC, purchased at Lowe's. We painted it flat black to help disguise it and protect it from UV rays.