Introduction: Acrylic Write Board With Red LEDs
So my wife was almost celebrating her birthday and I was unsure what to give her. Since we have our little son sleeping in our bedroom, we needed a night light not as strong as the bedside lamps we have. I thought about it and then decided to make one myself with a twist.
Please, bear with me, this is my first Instructable. Any spelling error or question please fire away :D.
The Idea was to make a base that would house 3mm LEDs and illuminate an acrylic piece. I decided to have a sanded/mate finish acrylic piece to give a more uniform light. I designed some parts on freecad and printed them on my 3d printer, other than that was manual labour :D. So, lets go to the point. The 3d designs are available at Youmagine and Thingiverse and also here.
Bill of materials:
19 - 3mm red leds (or the color you want, take care that different colors may need different resistors);
1 - 30v (or other - change the current limiting resistors accordingly) Power supply - got it from a busted printed.
- heat-shrink tube
- Electric insulation tape
- 2 printed parts
- I used an old acrylic board that I used as printer bed for my prusa. The acrylic thickness is 5 mm.
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Step 1: Cut the Acrylic and Sand
I sanded it (a lot) with some sand paper and then I measured a rectangle of 150x100 mm.
To cut it, I started really slow with the hacksaw, if you go fast, you melt the plastic and can easily fail the mark. After all cutting done, I scraped the sides with am utility knife to clean the burrs and then sanded it on top of a glass I scrapped from an induction heating plate.
After sanding the plate, I decided to sand a little bit more on the edges, to make it a little bit rounder and softer on the touch, but at this moment I already decided wich was the bottom part edge. I decided to leave that edge as square as possible, in order to collect maximum light from the leds.
Step 2: Wiring the Leds and Assembly
Having the acrylic board ready, it was time to assemble the leds and solder them. the design has 19 holes evenly spaced.I decided to make two blocks of leds. 1 with 10 led in series and other with 9. Each of this had a current limiting resistor of 1.5k ohms since the power supply I used is a 30v one from a busted HP printer.
After soldering all the leds, I added the resistors and protected the leads with some heat-shrink tube, inserted the cable to the power supply through the base hole and measured a place to make a knot that would serve as a strain relief. Soldering and some electric insulation tape after and all the wire was done.
The only thing needed to do now was assemble it, test it and finally give it to my wife :D.