Introduction: Wirelessly-Charged Epoxy LED Cube Lamp
This portable LED cube light is made from solid epoxy resin and is powered by a battery, so it has a ton of uses -- a mood light, a party light, a night light, etc. Basically, it is just fun and mesmerizing to watch :) As icing on the cake, it has a wireless charging receiver built in to it, making it 100% wireless. One of the primary motivations for this project was to try a wireless charging receiver in conjunction with a battery in an LED light. I've seen a lot of people add wireless charging transmitters to anything and everything, but haven't seen wireless charging receivers used in many projects, so I wanted to try one out.
This is entered in the REMIX CONTEST -- if you enjoy it, I'd greatly appreciate your vote :) https://www.instructables.com/contest/remix2019/
Make sure to check out the YouTube video at the top of this instructable, since often the video demonstration is helpful in understanding the instructions here.
Since it has the wireless charging receiver, you can charge it with any Qi wireless charger (like those used for Androids and iPhones), or make your own custom wireless charging base to really take it up a notch. All the electronics are off the shelf parts from Amazon, including the music reactive sp106e LED controller. This controller is pretty darn cool. It does solid colors, patterns, and even has a built in microphone for music syncing. Music controllers I've tried in the past have always been too blinky/flashy - like an out of control strobe light. As a result, I've often gone through the tedious Arduino programming to create my own music controllers. But, this one has much improved music reactive programming, smoothly blending in and out of patterns, instead of using binary on/off programming.
As for the aesthetic design, the shape of the lamp was inspired by several other cube lamps I've seen, and particularly by Darbin Orvar's fantastic concrete light cube: https://www.instructables.com/id/Concrete-LED-Ligh...
Step 1: PARTS LIST
· Melamine shelving – buy at local big box store
· black caulk
· Heat Gun: https://amzn.to/2seaErS
· Total Boat Epoxy Resin: https://amzn.to/2RFzYRS
· 5V LED Strip: https://amzn.to/2Emga2h
· 5V music sync LED controller: https://amzn.to/2PArObU
· LiPo Battery: https://amzn.to/2DVfFKZ
· Wireless Charging Receiver: https://amzn.to/2NeXBQp
· Wireless Charging Pad / Transmitter: https://amzn.to/2VaRZJH
· Battery Charging Protection Board: https://amzn.to/2BKdJF3
· Aluminum Foil Tape: https://amzn.to/2L36CK5
· Epoxy/Plastic Polish: https://amzn.to/2sljlQm
· Fine grit sandpaper (to 2000 grit): https://amzn.to/2smxPPW
· Cordless Drill & Driver: https://amzn.to/2F9y0b5
· world’s Greatest Sander: https://amzn.to/2PLUJOB
Step 2: Make the Melamine Form for the Cube
The main form is cut from ¾” melamine, and has four sides with mitered joints and a base – pretty simple. You can pick up a large sheet or melamine shelving for this project.
1. Cut a base piece that is at least 6.5” x 6.5” (it can be bigger, since sides of form just rest on top of it).
2. Cut a long (at least 34”) piece of 5” wide melamine (5” is height of the form) using table saw or circular saw. This piece will be referred to as the side board from hereon.
3. Cut a long strip (at least 34”) of melamine about 1” wide with a slight draft angle (I used 5 degrees) on each side. Table saw or circular saw works. This piece will be referred to as the channel strip from hereon.
4. clamp the channel strip on the side board (don’t attach it yet), and mark the spots where you will make 45 degree crosscuts, to cut out the four sides of the form. The marks should be such that inside width of each side is 5”.
5. Now use a nail gun (or nails and a hammer) to attach the channel strip to the side board, taking care to avoid nailing where you’ve marked for you mitered crosscuts.
6. Once the channel strip is nailed to the side board, cut out the four sides as you marked from the side board.
7. Use aluminum foil tape to cover the exposed particle board on the sides of each channel strip.
8. Use super glue and tape on the outside of the joints to attach two mitered sides to the base, then apply caulk to the seams on the inside of these pieces. (See my past instructable for concrete form caulking for more details – I used the same technique here: https://www.instructables.com/id/DIY-White-Concrete-Table-W-Live-Edge-Maple-Inlay/ )
9. Then attach the third side, caulk, and repeat again for the fourth side.
10. After the caulk is cured, peel away the excess as best you can, and spray the inside of the form with a mold release spray.
Step 3: Epoxy Pour #1
I used a 2:1 epoxy resin to make the cube. Since the epoxy can’t be poured too deep, I did this with a series of 1/2" epoxy pours to build up the epoxy in the melamine form.
2:1 Epoxy Resin: https://amzn.to/2ElKHgz
I could do ½” pours because my shop was about 55 degrees F, but you’ll likely want to do a bit thinner layers if your shop is warmer. Slow hardener also helps pour thicker, by slowing the curing reaction (and thus reducing the heat produced by the reaction).
For each layer of epoxy, mix at a 2:1 ratio of epoxy to hardener. I recommend using paint cups so you can just pour straight into the cup. Then add 6 or 7 drops of black epoxy pigment. This is the pigment I used: https://amzn.to/2Ss1KkY
Let the resin cure for 1.5 – 2 hours, mix the next layer, and repeat until the form is full. If you have to stop and the epoxy hardens completely (e.g., more than 18 hours), use 80 grit sandpaper to scuff up the top of the cured epoxy before pouring the next layer. As long as you wipe off the dust from sanding thoroughly, the scuff marks will disappear completely when the next layer is poured.
Step 4: Demold the Cube
Once the last layer of epoxy cures (e.g., 24 hours or more), remove the melamine form. I used a cheap chisel to pry the form off, but you can use whatever tool comes in handy. The whole surface is going to be cut even, so it doesn’t matter too much if you scratch the epoxy during form removal.
Step 5: Rough Shaping the Cube
Next you’ll want to get the sides nice and flat, since you’ll likely have imperfections when you remove the epoxy from the form. If they aren’t two bad, you might be able to get away with using a disc sander and/or orbital sander. However, I found it easier to run all sides through the table saw to square them up. I would make 2-3 passes to cut up to the max height of the blade on a given side, then flip the cube over and make 2-3 passes to finish cutting off the other half of the same side. Then I repeated this for all four sides of the cube to square up the sides. Making multiple passes through the table saw allows you to push the cube through the saw more quickly, so that heat doesn’t build up (which runs the risk of softening the epoxy and cutting unevenly).
After squaring the sides at the table saw, it is time to carve out the cavity for the electronics. I used a forstner bit and router on the router table to carve this cavity in the bottom. However, I’m not going to go into more detail on this step, since I would actually recommend using foam (e.g., pink insulating foam) to create an insert in the form when you pour. Pouring over a foam insert will provide a cavity in the cube right out of the form, so you don’t have to waste epoxy by carving out the cavity later.
After the cavity is created, use a 5/8” forstner bit to create a tunnel for the wiring between the LEDs in the channel and the other electronics in the cavity. You’ll drill from the channel to the middle of the cube, and then up from the middle of the cavity until you meet the first hole you drilled. The result is a sort of upside-down chimney between the cavity and the channel.
Step 6: Wire the Electronics and Test the LEDs
You’ll want to wire up the electronics now and test the LED strips, before you cover them in epoxy, since they’ll be in the cube permanently once cover them in white epoxy.
Here are the electronic parts:
- TP4056 charging protection board: https://amzn.to/2BKdJF3
- pigtail power jacks: https://amzn.to/2tC9wyA
- individually addressable 5V LED Strip: https://amzn.to/2Emga2h
- SP106e 5V music sync LED controller: https://amzn.to/2PArObU
- LiPo Battery: https://amzn.to/2DVfFKZ
- Wireless Charging Receiver: https://amzn.to/2NeXBQp
- Wireless Charging Pad / Transmitter (optional): https://amzn.to/2VaRZJH
- 3-pin JST connectors: https://amzn.to/2Xo3xLq
(1) Cut off the JST on the power/ground wires on the LiPo battery, and solder these wires to the Battery +/- terminals on the TP4056 board.
(2) Connect the micro usb cable from the wireless charging receiver to the micro USB jack on the TP4056 board.
(3) Solder the +/- output terminals on the TP4056 charging protection board to the +/- wires on a male pigtail power jack, then plug the power jack into the SP106e LED controller.
(4) Cut a length of LED strip so that it wraps around all four sides of the channel in the cube. (If a JST isn’t already connected to your strip, then solder a 3-pin JST connector to the end of the strip. Make sure the arrows on the strip are pointing away from the end where the JST connector is soldered to the LED strip.)
(5) Connect the 3-pin JST on the SP106e controller to the JST on the strip, and use the remote to turn it on and make sure the LEDs work. (Optional modification: I wired the sp106e controller to two LED strips in parallel. To do this, you’ll simply splice in a second JST to the JST coming out of the controller, so you can attach it to a second strip. This is optional, but I really like the look of two strips in the channel running in opposite directions around the cube, as compared to one single strip.)
Step 7: Pour the White Epoxy to Diffuse the LEDs
Now you are ready to cover the LEDs in epoxy. In case you are wondering, I’ve done this multiple times, and pouring epoxy over non-waterproof LEDs is totally OK – it doesn’t ruin them.
- White resin pigment: https://amzn.to/2EdZVTA
(1) Before putting the LED strip(s) into the channel, use sandpaper to scuff up the insides of the channels.
(2) Next, you’ll thread the wires for the LED strip (or strips) through the chimney shaped tunnel, so they come out in the cavity in the bottom of the cube.
(3) Use a hot glue gun to fill in the wiring chimney, which will prevent epoxy from running out of the channel and going into the wire chimney. Be generous with the hot glue, and make sure it goes pretty deep into the chimney. The last thing you want is a leak and epoxy going where you don’t want it.
(4) Then secure the LED strips to the channel with super glue. This is necessary since the adhesive on the back of the strips can come loose when you pour epoxy over them, and you don’t want them floating up in the epoxy when you pour.
(5) Cover the channels on three sides of the cube with pieces of melamine. Use clamps to hold the melamine tight against the cube, and then use hot glue at all the seems to close them up. (Note: in the video, I use aluminum foil tape to seal off the channels on three sides, then poured the epoxy in the channels. This works too, but I also tried melamine, and found it a bit easier since you can avoid having to sand and scrape out the sticky side of the aluminum tape, which gets embedded in the epoxy.)
(6) Mix up the 2:1 epoxy, add 4 to 5 drops of white pigment, and pour it into the channels. Pour enough so it is a bit proud on the top channel.
(7) Wait 24 hours, and remove the melamine (or the aluminum tape).
(8) If necessary, mix some more white epoxy to fill in any channel where the white epoxy is not proud of the black epoxy (e.g., where the channel is concave)
Step 8: Cut the Acrylic Bottom Plate for the Cube
For the bottom of the cube, I used a piece of 1/8” thick translucent smoke grey acrylic, cut to slightly smaller dimensions than the cube on the table saw.
Smoke grey acrylic sheet: https://amzn.to/2Nt2jtV
I first used a router to trim out a thin (about half the thickness of the sheet) cavity in the acrylic, in the shape of the wireless receiver. I also used a rotary tool with diamond wheel to cut a little channel to hold the TP4056 board. Don’t attach the parts now, however; we’ll come back after polishing to finish the electronics.
I then clamped the acrylic sheet to the bottom of the cube (so it covered the cavity), and drilled holes through it and into each corner on the bottom of the cube. These holes allow for four machine screws to be used to attach the acrylic sheet to the bottom of the cube. I used ½” #6 machine screws, if I recall correctly. The size of the screws doesn’t matter too much, but generally smaller is better for this task. I then went back and used a countersink bit on the holes for the screws, so they would sit flush with the acrylic once screwed in.
Step 9: Sand & Polish the Cube
Sanding and polishing is tedious, but if you take your time, you can get this cube with an amazingly cool finish – it reminds me of a gleaming black Steinway & Sons piano.
(1) I used a belt sander and/or an orbital sander to sand the white epoxy flush with the black epoxy. (I used the belt sander first, then the orbital.) If using an orbital sander, it is best to use a hard sanding pad, which prevents it from inadvertently rounding off corners, and yields a nice flat surface. I used 80 grit pads until all the white epoxy channels were sanded flush.
(2) After getting the surfaces sanded flat, use a random orbit sander to sand up to 400 or 600 grit (as high as you’ve got).
(3) Then switch over to the really high grit sanding pads for a wet sanding by hand. Before wet sanding, use screws to attach the acrylic base plate to the cube (wet sanding and polishing will also polish the sides of the acrylic). Work your way up from 800 grit wet hand sanding, to 1000 grit, then 1500 grit, and 2000 grit if you have it.
(4) After the wet sanding, you’ll use the Novus 3-step plastic polish. The three parts can all be applied by hand with lint free rags. Or, you can use a power buffer if you have one.
Step 10: The Wireless Charging Pad
I also created a custom wireless charging pad for the cube. However, it works the same on any standard Qi wireless charger (like those that charge Androids and iPhones). Since you can use any standard wireless charging pad, and because there are already a ton of Instructables explaining how to make wireless chargers and add them to just about everything, I’m not going to go into detail here. The YouTube video at the top does explain the process of making mine, and I’ll include some photos of the process here.
Step 11: Installing the Electronics
Before installing the electronics, you’ll want to create sound holes in the cube. Figure out the side of the cube you want to be the back of it (likely the same side where the wires from LED strips enter the tunnel to the cavity). Drill a few small holes (e.g., 1/16”) through this side and into the cavity. These will allow sound to enter the cavity and reach the microphone in the sp106e LED controller.
Now it is time for the final installation of the electronics we tested earlier. Here is an overview of the process:
(1) Use super glue to attach the wireless charging receiver to the inside of the acrylic base.
(2) Use super glue to attach the TP4056 charging protection board to the slot you already cut for it, on the inside of the acrylic base.
(3) Connect the micro USB cable on the wireless charging receiver to the micro USB jack on the TP4056 board.
(4) Connect the power jack on the TP4056 board to the LED controller, and the JST connector(s) on the LED controller to the LED strip(s).
(5) Before securing the electronics, fire it up and make sure it works. Once that is verified, use a hot glue gun to secure the battery and LED controller in the cavity, making sure to leave room for theTP4056 board. Try to orient the little hole for the mic in the side of the controller so it faces the holes in the cube you drilled.
(6) Once the hot glue sets up, screw the acrylic base (with the charging receiver and TP4056 glue to it) to the cube.
(7) You’re done – enjoy!
Step 12: Have Fun!
Step 13: Check Out the Full Video!
If you have questions, check out the full build video up on my YouTube channel. I check occasionally for comments and questions here, but am sometimes a bit quicker to respond in video comments.
Second Prize in the