A Lit Multi-Layer Unicorn in Acrylic
2019-03-01 16:00:00 UTC
You can find tons of examples of "edge lit acrylic" all over the internet, and I was interested in doing something like that, but I want to put my own twist on things. After a bit of thinking, I figured, "If you only need to light one edge, you could light 4 layers on individual edges, right?" Thus began my 2 month long journey!
First, I experimented with cutting the unicorn into a trace operation on my CNC machine:
![The unicon trace in a single layer on acrylic](/unicorn/2019-01-21 17.44.20.jpg)
Then it was time to split the design into 4 layers and see if "marrying" them back together would work out ok:
![The unicon in four layers, layed apart a bit](/unicorn/2019-01-25 18.28.16.jpg)
And when you line them all up:
For all of these I used a normal 45 degree Vbit at 70ipm 6 on my makita and very little depth. Fair warning, get a dust boot with bristles. Acrylic "chips" (really, shavings) are very light and go everywhere and get statically charged very easily so you find them stuck to everything.
The frame needed a channel around the acrylic sheets to hold the LEDs and some way of holding the sheets in place. I created some L shaped edges and a channel behing them for the lights. The first prototype was pretty rough -- just some 2x4's glue together and milled out, but served to prove out the idea.
![The prototype frame with 4 demo layers in place](/unicorn/2019-02-03 11.46.11.jpg)
In the image above, you can also see that I'd painted the edges of the 4 layers so that they all had a single exposed edge. I originally tried to just use a sharpie marker, but that didn't adhere well enough and I ultimately resorted to using acrylic paint in two applications.
Parts and Pieces
- Acrylic Sheets
- LED light strip -- I went with RGBW, but you can go for RGB without a White compontent, what you must get, though, is addressable rgb's. Non addressable LED strips will only show a single color and would defeat the entire purpose of this build!
- Wifi controller -- You could substitute this with some other controller or even an arduino you custom program, but that's up to you. This controller was convenient and has worked well enough.
- Power Supply
- Wood to carve the frame -- I think I spent about $30 on project boards from Home Depot
All in this rounds out to about < $150 in project materials.
The Final Frame
After the prototype I realized I didn't have anywher to put the wifi controller, so I expanded the left/right sides on the frame so I could carve out a space in the back for the controller. Finally it was time to get to work, starting with turning the project boards into a single stock piece:
![The project boards glue up process](/unicorn/2019-02-23 12.43.31.jpg)
And get it in the machine:
![Mounted inside the CNC machine](/unicorn/2019-02-23 21.02.54.jpg)
You can see I've already milled out the mounting holes here so that I can screw the work piece down in the middle of the machine. This was a really great way to hold down the stock as in meant there was absolutely no work holding pieces in the way of the dust boot, etc. No crashing!
![The frame done](/unicorn/2019-02-26 23.17.32.jpg)
Huzzah! The final frame is done. In this picture the wood has been treated with Danish oil and sanded a billion times. What is not pictured is the backing piece which hides the LED light from spilling out the back of the frame and holds the acrylic pieces in. It's a simple rectangle cut out, though, so you're not missing much :)
As the final frame was resized a bit larger, I redid the engraving and did a much better job on cutting out the sheets. Instead of trying to hold down the acrylic from above, I used the "tape-n-glue" technique where you apply tape to the machine surface and the stock, then put a layer of superglue between the tapes to hold it down. Works extremely well for acrylic engraving and, more importantly, for the cut out step. I also spent a bit more time being careful about painting this time, heh:
![A close up of the painted edges without all the nasty splatter from the prototype](/unicorn/2019-02-27 22.23.19.jpg)
Finally I can lay the LED strip it, connect everything up and power it on!
![The full unicorn frame and acrylic, assembled and lit](/unicorn/2019-02-28 18.04.58.jpg)
And, finally, a night shot showing off the multi-layer lighting effect in full force:
![Every layer well highlighted in a different color](/unicorn/2019-02-28 18.05.32.jpg)
The Fusion 360 files for the frame and engraving are available below: