So it’s nothing new when I interrupt one project for another, but this time was a bit different. My friend Brooks over at Sunshine Labs asked me to make her a sign for her new business. She didn’t give me specifications or her ideas, just make me a sign. I couldn’t just do an ordinary sign, not for Brooks who had not one but two dresses with NeoPixels. So I took a look at her logo,
and thought… it needs to stand out more and have lights (but not NeoPixels, not this time). So a bit of quick work with a laser cutter with 4 different acrylics. Some translucent white, some very thin black and some neon-orange & blue. The neon blue went behind the black as a drop shadow. The orange was heated and bent, mainly to see how well it does edge lit.
So the initial test looked good, the orange shined and the blue accent was subtle. Now on to the hardest part, bending acrylic in multiple stages to create a 3d representation of her logo. Here is a shot where I have made the first bend and I’m now heating the second area to bend. The odd notch in the wood I have laying on top is so I can see the acrylic. It changes optically when it gets hot enough.
After 5 tries and lots of scrap, I finally got one perfect. A helpful hint if you are ever working on a project bending acrylic. Don’t have a fan on nearby, it takes much longer to heat and it heats unevenly.
What may not be obvious in this picture is that the logo is not just a bend in a straight piece of acrylic. It was cut so that it would have a forced perspective. The reason for the perspective cut and all the little divots in the ends is for LEDs to be inserted for edge lighting the acrylic. So even when standing directly in front of the sign you will see the edge lighting.
Here is the patter I used to cut the piece. At each point that it angles is where I bent the acrylic.
Here is a shot of how the LEDs are to be mounted. I didn’t use blue tape in the final piece. I used heat shrink tubing and some electrical tape as I wanted this light isolated from the rest of the sign.
Doing the letters was a bit of a pain, but blue tape to the rescue. After aligning each letter with it’s blue drop shadow I taped them together then use acrylic cement. I despise the bottles they give you as they leak (the cheap one I had anyway). So I used insulin syringes to apply the cement.
I couldn’t find a frame, so I decided to make one instead. I ended up cutting two pieces from MDF and gluing them together. I needed the depth for the light to disperse from the LED back lights to the white acrylic, otherwise you see each individual led shining through.
Next was mounting the led back lighting. But first some math, to evenly space all the led strips so that there was uniform brightness (that sheet of paper on the left are all my calculations). I shouldn’t have bothered. The strip lighting I picked up online and it was insanely bright. Ended up cutting the voltage down and then adding a filter screen to get it to where it didn’t overpower the logo effect.
The LED light strip had glue on backing that was incredible stuff. When I removed one piece it destroyed part of the dry erase board I used for the background. So quickly line it up and solder it in….
and test the lights
Back to the logo for a second. The idea behind having LEDs in the logo with the edge lighting was for a specific effect. A slow churning of light, like the sun. Never fully off, but constantly moving. To this end I used a Texas Instrument TLC5940 connected to a Arduino Pro Mini. The program was simple.
1. Randomly pick one of the 8 LEDS, if it’s off turn it on, if it’s on turn it off.
2. When turning and LED on or off, change the brightness from 100 to 4095 (or reversed) over 2 seconds.
I kept a base value of 100 so the LEDs never fully turned off.
and a final light test
Every project I work on usually includes something new, either learning a new tool or using a new material. So every project there is always a learning curve. On this project, I had originally planned to have the blue shadows of the letters light up as part of the animation. I did some testing and it looked good, but I tested late at night with the lights dim, so when I turned it all on for a pre-assembly test the lights were non existent, washed out. When I lowered the intensity of the white back light, the white acrylic glowed blue (not what I wanted). So in the end I removed the blue LEDS and left the blue as an accent piece. The sign looks good and quite a few people have told me the pictures do not do it justice, but I still wish I could have done the animation of the letters. In hindsight I should have used blue mirrored acrylic, this would have focused the light in the blue area and not let it ‘escape’ into the white acrylic.
Here is the sign with it’s molten movements
I don’t track time working on projects very well. Usually I just find my first file and check the date stamp, nevermind that all my projects start on paper. This was not a one weekend project and took me far longer to do than I intended. My first file has a date of April and I didn’t deliver this until August, but that’s cause I’m a busy guy.