Feb 222020

The tube to LED tube effect mastery tubes through many strange tubes. Some tubes are interesting concepts that become poorly thought out attempts, some tubes suffer from a lack of resources or patience in fabrication, some just don’t make any sense at all in retrospect but I have to assume they did at some point.

Here we have a few failed, but still educational, tubular journeys I’ve made recently.


At 100% brightness with half red and half blue so you can see the blending issue.

While I was at the hardware store looking at tubes I couldn’t help but notice the largest diameter tube in stock was about right to try edge lighting with an LED ring instead of through the center. They’re 1-7/8″OD and a 12-LED ring lines up right the LEDs packages. It took a little thought to get a secureish connections with a 3d printed holder. Unfortunately the results were very underwhelming. The light mixes completely in the first two inches so you lose any color differentiation between the LEDs pretty fast. And it dims out after about eight inches. Worse the look of the light coming from the tube wall instead of inside the tube doesn’t look very cool to me. Just looks like a giant, crappy fluorescent tube with a color temperature that’s just wrong. The tube was about $10 and I wasted a lot of time getting the holder right, but my time is worthless and I can reuse the LED ring for other projects. So not a huge loss and I might try using the tube for something else later.


These modules are ridiculous, but I’m semi-committed to figuring out something to do with a lens with such an insanely tight beam that the RGB channels don’t even overlap. After giving up on bouncing the light off anything since literally any other LED is a better option- I decided to see if I could capitalize on the insanity of the module’s design by projecting the beam into a tube. That makes it sound like I really thought outside the box to find a use, but I think it’s pretty clear why my first thought was tubes.

The lens turned out to fit a 1″OD|3/4″ID tube perfectly so I just printed a little collar and pumped in a bead of silicone to make a watertight so it could hold water. I didn’t go with silicone fill in the tube because it’s just a lot of silicone for a test. The results are interesting, it lights up the tube and blends pretty well. I think two of these on opposite ends could light up a tube at least 2-3′. I’m not sure that’s worth buying any more of these but I might have found a way to at least put them in a one-off giant-tube build. Not sure why I’m calling this a failure because it kind of worked out, but these freaky little projector LEDs are pretty much a mistake to begin with. I’d like to ask whoever designed them what purpose they had in mind.


This is supposed to be an effect light with tubes that ‘fill’ a little bottle or shotglass at the top with light. After I had the basic build worked out I was somewhat shocked to discover I do not presently own a shotglass. I had the acrylic case from an hexbug toy so I chopped it down and filled it with silicone just to top off the prototype build. Once you put the silicone on its kind of a done deal, you can kind of unmess it after it cures on PLA, but it’s not worth it.

It took me a bit to see it, but I am no longer comfortable with the overall aesthetic of this build. I should have waited until I got a shotglass. But I’m going to add another section of tubing to complete the loop back to the base. so this prototype build just is what it is, which is a light that doesn’t not remind people of a dong enough to not be a considered failure.


These tests actually gave me some other ideas that I’ve had some success with, but I’m going to save those for a post that isn’t about fun mistakes. So stay tuned, there might be a post about mistakes involving fresnel lenses and\or highlighter fluid to look forward to, and definitely more tubes.

  One Response to “Tube Detours”

  1. […] is the shotlight prototype I ‘fixed’ by replacing the dome top with a vinyl tub. I still haven’t made the version with the […]

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