With the electronics done on my RGB project, I moved on to the physical construction.
As a veteran of a number of these projects, I’ve learned that the electronics part is always the easy part; it’s all of the physical construction (wiring/cabling/support) that takes the time. I’ve also learned the new projects need to be quick to put up; it already takes too long for me to put up the current displays.
The LED strips that I’m using are quite flexible, so they need some support. I chose 1/2” EMT electrical conduit as my mounting method. I have 67’ to cover, so I bought 7 lengths of the tubing for about $3.50 each. The strip has an adhesive backing on it (it claims to be a 3M adhesive, but counterfeiting is rampant in China, so I’d be surprised if it is…), so it’s a simple matter of attaching the strip.
The first step is to mark a straight line along the conduit.
To do this, you need a way to hold the tubing so it won’t spin. I used a 8’ cutting guide that I have, and a sharpie to mark the edge. If you don’t have that, a baseboard in a room that has hard flooring would work just as well.
Next, slowly peel of the adhesive of the strip as you move along the tubing, and stick it down. The strip is made to be attached to a flat surface, so it won’t adhere perfectly. I used zip ties to give some extra security.
I needed a nice way to joining the pieces of conduit together. I originally just wanted to use conduit connectors, but they don’t really hold the joint very straight and they make the tubing wider, so I did some searching in my hardware store, and found some connectors for flexible pipe that worked just fine. One end is a tight fit, and I ground down the connector so the others just slide on. I’ll note in passing that inside diameter of 1/2” EMT is 0.6 inches, and the outer diameter is around 0.7 inches. Here’s a picture of them.
This shows a tactical error I made; the strips can only be cut on the segments between them, so I let them run long, and made sure they overlapped correctly. It was a bit of a pain. On the second set, I got smart and trimmed the conduit to the length that I needed. Here’s what the completed sections look like:
There are connectors at both ends because I need to feed power from both ends to keep the voltage constant; they are Molex connectors that took a long time to put on; each one gets crimped and soldered.
I bought a 250’ spool of 12-gauge landscape wire, and then soldered on some more connectors. I used hot glue to insulate the connections and hold everything together.
After a lot of work, I got it done, and then surveyed the carnage:
and here are a couple of shots of the final result:
That intense red line is the RGB strip. Note that it’s really hard to take crisp pictures of lights, as they tend to bloom.
Here’s a closer picture; you can sort-of see the individual leds. At this distance – 20 feet or so – you can see the individual light sources pretty easily.