2x4 LED Chandelier With Music Reactive Lights

This was a fun project I made for the #two2x4challenge. I'm not in time for the lighting contest, but I am entering the power supply contest. Votes are appreciated :) You can vote for me in the power supply contest here: https://www.instructables.com/contest/powersupply/

There aren't too many pictures, but the full build video should explain more than pictures could. Just watch the YouTube video and follow along with the steps, and everything should be fairly self-explanatory.

Supply List

1. Two 2x4s

2. Acrylic or Plexiglass sheet (1/2" if possible, but 1/4" will work too)

3. LED strip lights, 60 or 144 LEDs per meter (I used SK6812 WWA 60 LEDs/M)

4. 5V power supply (I recommend a 5A - 8A power supply)

5. Arduino Nano (any arduino will do)

6. Electret microphone breakout board

7. Momentary push button

8. 10k potentiometer

9. bread board(s)

10. hanging kit

11. cloth covered wire

12. Arduino code (I'll post to Github soon)

Step 1: Deconstruct the 2x4s

First, you'll want to remove the rounded edges of the 2x4s. To do so, just run the 2x4s through the table saw and trim off the sides. Trim one side of both 2x4s, adjust your table saw cut width, then trim the other side, so both your 2x4s are the exact same width.

Then cut your 2x4s down the middle. 2x4s are 1 5/8" thick. To split it on the table saw, set your stop on your table saw to 1", and adjust your blade height to just slightly more than half the width of the 2x4 (about 2"). Run your 2x4 through once to cut halfway through along the width, then flip it over and cut through the other half to split it. When you do this at 1" stop on your table, subtract 1/8" for the cut, and you'll split your 2x4s into 1" and 1/2" sections. We'll call the 1" half the bottom, and the 1/2" one the top for ease of reference.

Step 2: Route an LED Channel

Next, you'll cut a channel down the middle of the bottom (1") half of each 2x4. I made mine 1.5" wide and about 1/2" deep. (You could make it narrower, but the wider it is, the more dispersed the light will be coming out of the openings) I used a 1 1/2" bottom cleaning router bit on a router table, making a couple passes and gradually increasing the depth. You could use any bit you like to cut the channel, however. If it is narrower, you might need multiple passes. You could also use a table saw or even a circular saw, to gradually cut the channels.

Step 3: Reconstruct the 2x4s

Now you want to glue the top and bottom parts of the 2x4s back together. Just glue and clamp. Now you've got a hollow channel through the LEDs.

Step 4: Construct the Frame

Now you will cut 4 sides using a miter saw. Essentially, you are making a picture frame. There are tons of tutorials on making a basic picture frame so I won't go into much detail. Just Google search for one if you need more details.

Step 5: Cut the Light Slits

Tape the inner and outer edges of your 2x4 frame with a few layers of painters tape to avoid tear out. Then use a 1/2" channel bit on your router to cut slits at random angles all around your frame. I used a scrap 2x4 clamped to the 2x4 frame as a straight edge guide for the router.

Then give everything a quick sanding (a random orbit sander works best, but you can sand however you like).

Note that I applied stain at this point, but that was a mistake. You'll get nicks and cuts when you are trimming your acrylic strip inserts, so best to stain after the acrylic strips are done.

Step 6: Install LED Strip

Cut a large (e.g., 1.5") hole in each corner on the top of your 2x4 frame that allows you to turn the corner when threading the LED strip through. Now thread your LED strip through the channel. The strip will be in the channel loosely. I used super glue and clear silicon caulk to hold the LED strip in place, but this is optional. Plug in the LED strip and make sure it lights up before moving to the next step, since it will be difficult to remove after you install the acrylic strips.

Step 7: Acrylic Strip Inserts

I cut a few 1/2" wide long acrylic strips on the table saw, then cut them down to approximate length needed on the miter saw (not shown in video). I suggest cutting a shorter strip starting slightly wider than 1/2", test it to see if it will fit in the slits in your 2x4s, then trim the width down gradually on the table saw until you get the width so it fits the slits in your 2x4s snugly (e.g., so you have to use a rubber mallet to push them into place and they fit tightly). Once your width is dialed in cut longer strips.

Then take the long strips to the miter saw and cut them into smaller pieces. I found that 4.5 - 5" strips worked well. The length doesn't need to be exact. Just cut the strips to a length so a half inch or so sticks out on either side of the 2x4 when you insert them. Now use a dab of super glue to hold each acrylic strip in place in the 2x4 and insert all of them (using a mallet if needed). NOTE: It is really important you have a snug fit and use super glue. The acrylic strips need to be in the slits tightly so you can cut them flush with the 2x4s, and they don't fly out when you cut them.

I then used a circular saw to trim the acrylic strips flush. NOTE: THIS IS DANGEROUS, DON'T HOLD ME LIABLE IF YOU DO IT THIS WAY. A safer way would be using a table saw crosscut sled if you have one big enough. The safest way would be to use a flush cut hand saw to trim the acrylic flush. This is tedious, but I recommend this technique if you can't do it on the table saw. Be sure to wear eye protection too while doing this.

Step 8: Stain and Seal

I sanded everything down up to 180 grit, then applied one coat of a walnut stain + poly combo. You can finish however you like, of course. Then just plug in and fire it up.

A note on Arduino coding and wiring. I'll put the code up soon, or just send me a message and I can send it to you as is. If you don't want to get into all this, just get a pre-manufactured LED music controller for aobut 30 bucks, like this: https://www.amazon.com/Mokungit-DC5-12V-WS2812B-Di...