Acrylic Light Panel Rave Totem

Hi all this is my first Instructables post. I will be showing you guys how I designed and made my rave totem using an acrylic panel underlit with some LED strips. Its pretty easy in concept. Let's do this!

Supplies

1. Telescoping pole (I used a 1" diameter lightweight metal paint roller extender)
2. 3-D Printer (We used some one-off Kickstarter project from 2014, so if we used that, you could probably use any printer!)
3. Carbon Fiber PLA (Normal PLA should work, PETG maybe a step up from that)
4. 8mm steel rod
5. Portable battery
6. 10 foot long micro-USB power cable.
7. Fiberglass resin
8. Acrylic panels (We used some acrylic from the cut-off bin at Tap Plastics, super cheap)
9. EVA Foam
10. Neopixel strips(WS2812B RGB LED strips)
11. Digispark (Any microcontroller should work if you know what you're doing).
12. Spare machine screws.

Step 1: Design the 3D Print

TODO: Add more images.

So the first thing you'll want to do is find your best friend who knows Fusion360 and is willing to work for free. Ramble about this idea you've had in your brain since quarantine started and get him all hyped up to design everything for you. I've found this is the best option to avoid buying a Fusion360 License.

In essence, the goal of this print is to mount an acrylic panel to a telescoping rod (We used a paint roller holder from Home Depot or something). Various iterations of the mount were printed and tested using the scientific method, shaking it vigorously in the air until it snapped. Using this method we improved upon the model until we were left with something very, very rigid; using 8mm steel rods to provide reinforcement.

The 3D prints took about 11 hours to print per. This could have been improved with a better printer but we did not have such printer available. I believe the infill was about 20%, which turns out is all we needed. Maybe we could have gotten away with less but... I'm satisfied. I don't believe the carbon fiber filament is necessary, I think with the extra rigidity all you get is a slightly brittle print. PETG will likely provide you more flexibility with less creep. For something like this, you want flexibility. Bendy means no snap. Rigidity is only best in some areas.

Step 2: Cut Steel, Paint Resin.

TODO: Add pictures

Trying to cut steel rod (I assumed it was aluminum) is actually a rather strenuous exercise, especially with a lack of proper tools. We succeeded at this task with a large bolt cutter (Two people needed to push down on the handles!). 4 cuts later and we tried to push them through the mount's holes, which did not fit, so I went ahead and sanded the interior diameter of these holes with a round file. Eventually everything fit snug.

After the steel rods were inserted, I realized we have about a week left before Hard Summer 2021. So we have plenty of time to experiment. I decided this iteration of the mount was going to be the one. My confidence in this decision was backed by my tin of Polyester Resin.
[Polyester/Fiberglass Resin is some pretty gnarly stuff, you do NOT want to breathe this or even get it on your skin, its very irritating and sticky. Always work outside with a mask or a fan blowing. However, what you're rewarded with is a wonderfully resilient material ]

I had looked up fiberglass reinforced 3D prints and in most cases the polyester resin is stronger than the print material itself. No fiberglass mat was used in this project, just resin. I quickly decided to start mixing it up and applying it to the mount. We did not have any chip brushes at our disposal so we used some kitchen sponges. I'd say it actually worked out better than the chip brushes. But my friend says the resin started dissolving the sponges. We applied the resin to all the outside surface making sure not to fill any holes with resin (masking tape does wonders). Eventually it was all finished and we left it outside under a heat lamp. The print had not cured for a very long time because I did not apply enough hardener to the mixture. Please make sure you add enough.

Step 3: Electronics

This whole project basically functions by the transmission of light through acrylic, any scratches on the surface will catch the light and re-emit it in different directions. The effect is a clear panel with glowing marks on it. So, what we need to do is shine light through a side of the acrylic sheet.

In the mount, we designed a channel for the LED strips to fit underneath the acrylic. These LED strips will sit flush below the acrylic and have contact with the acrylic sheet itself. We cut the strip and had just enough for 5 LEDs.

For the micro controller we used a Digispark. I love this micro controller, it is essentially an Attiny85 with a little USB bit-bang stack attached to a USB connector build directly into the PCB. You can program it with the Arduino software and they cost about 2-3$ each. Perfect for something like this. We may use a more powerful micro controller later if we plan on using a different control mechanism... maybe there is a microphone on board that changes the LED's color based on the volume of the music. But for now, the Digispark has just enough power.

My friend here programmed the LEDs himself using an HSL to RGB library and his own custom routine for looping over each color. There is a button attached to the Digispark that changes modes, The default mode is off, the second mode cycles through all the colors smoothly, the third mode pauses on the color in the cycle, and the fourth mode cycles through the colors while flashing on and off matching about 120bpm. (I could be wrong about all this, if you want to correct me you can check the code yourself).

For the power transmission, I had intended to keep a little portable power bank inside my fanny pack, and have a 10 foot micro-usb cable run all the way up the totem directly into the electronics. While the totem was fully extended, I measured the cable to a comfortable length so it could reach all the way from my fanny pack, up the pole, into the electronics without too much slack. Then, I cut the cable (at the micro-usb end) and soldered the red and black directly to the LED strip power pins. (These power pins are shared with the Digispark). We then zip-tied the cable directly to the mount with a lot of force. This way, when the power cable is yanked, it doesn't transfer that force to the electronics and damage them.

After all the programming; debugging; and soldering, we designed a little box attachment that we can shove all the electronics into to keep them tight and secure. This kind of thing is very important as it prevents the wires from moving around too much and wearing out the solder joints. Especially important for a festival totem that I intend to wave around in the air! We soldered everything together: Power cable to LED Strip; LED Strip/Neopixel to Digispark data pins; button to Digispark. Next, we cut the acrylic.

Step 4: Cut the Acrylic.

So this part was extra difficult. I did not have access to a laser cutter without traveling a long distance to my closest hackerspace. So, we experimented with different methods of cutting acrylic. Of course, the laser cutter is simply the best option, as it provides accuracy to a degree we can't achieve by hand. But, if you don't have a laser cutter on hand, then you can try these methods!

The basic design was a circle that can follow the curve of the mount (see last pic) and have a rectangle that extends down into the mount to interface with the LED strip.

So, after a long time contemplating (and searching for a Dremel cutting wheel). we decided the best method for cutting a curve into an acrylic sheet would be to melt with a hot wire. The first thing we tried was dismantling a Chinese disposable vape to harvest the Nichrome wire from the atomizer. This worked in our experimentation with high current power supply, but it was too thin to last very long. I had searched a hot-wire cutter on the internet and found some people were using metal guitar string as a Nichrome substitute. Luckily, both our parents are guitarists and had lots of spare wire for us to use.

Then, my friend and I spent an afternoon designing a simple hot wire cutter in Fusion 360. Essentially, all the hot wire cutter does is apply tension to a metal wire allowing it to not deform when the cutting material is pushed into it. Then, this wire is fed through a hole in a flat surface to provide a cut perpendicular to the material.

After all this was printed up and built, we attached the wire to my trusty lab-bench power supply that was dropped too many times. and cranked up the amps. The wire got red hot quickly and we could successfully cut the acrylic in a fine manner. However, one quirk of this device was that for effective cutting, we had to move the acrylic sheet up and down to eat up all the spicy hot thermal energy from the wire. So, this design was not perfect. However, if we wanted perfect we'd just build a laser cutter... and we did not have time for that.

A key issue that arose after the cutting was that the acrylic simply melted together at the seam, this was highly frustrating, as it resulted in a cracked piece of acrylic while trying to snap it out of the cut. My solution was to drill holes along the cut line before hot-wire-cutting. This would provide a sort of relief to the stress and made sure the acrylic would break along the seam. It worked pretty well and we were able to achieve a rough curve to the acrylic.

Afterwards, all we did was use a belt sander to finish the edges.

Step 5: Etch the Acrylic

This step is very simply and very satisfying. After cutting the acrylic and affixing it to the mount (there are simply two screw-holes which you can use 6-32 Machine screws or the equivalent metric screws to secure, drill through the acrylic). Then, you can etch using a knife or a screwdriver. Either of these worked for me. Some of the online tutorials I watched said you can use a Dremel with a sanding wheel to etch the acrylic. I found using the knife produced more defined, prominent cuts. I just placed a piece of paper with the little dipper on it behind the paper turned on the LED strip, and traced it with the knife.

As I said, this part is highly satisfying. You are essentially drawing with the knife on a clear acrylic surface, but your traces glow in all different colors. I could spend a whole day doing this. Be creative!

If you intend to use the laser cutter, make sure your cuts do not go too deep into the acrylic. We used 1/8th inch acrylic so I'd recommend you go no more than 2mm into the material. With the vigorous shaking of the totem, you don't want a crack to form along your laser cuts. (I've actually never laser cut acrylic, this is just something I suspect would happen and I want to be safe about it).

Step 6: Cover With Foam

At this point, your rave totem is done! Its fully functional and looks awesome!

However, those steel bars look a little dangerous don't you think? Of course, you'd never let the totem fall on some unsuspecting raver. But, just to appease the security at the event, you just want to be sure its considered safe.

I decided to cover the whole thing in foam. EVA foam is what I decided to use, just because its very flexible, thin, black, and I had a lot of it from a different cosplay project I was working on. I suppose you could use a polystyrene cut to just the right dimensions to fit over the bars, but, I don't recommend that. Styrofoam is highly brittle.

All I did, was cut foam to slightly bigger dimensions and twice the width of the mount, so I could wrap it all the way around. and tape it closed. I used electrical tape because of its flexibility and how it keeps tension in just the right way. Its also smoother and looks prettier than duct tape. I just wrapped the whole thing in electrical tape and made sure to fold the foam properly to cover everything (even the electronics box, the button was still functional through the foam!).

Then, I cut a thin piece of EVA and wrapped it all the way around the acrylic. It doesn't look as good as before but hey its not too bad either. I then plastered stickers all over the thing for a more "festivityous" look. I even had a Hard Summer sticker I got 2 years back!

This whole thing was stress-tested by repeatedly bonking my friends on the head with it. Results were at worst "annoying". Mission accomplished.

Step 7: Photo Dump

Hard Summer was a whole lot of fun. It was a lot of pent-up energy from quarantine released. The entire trip went off without a hitch! Everyone had a great time and nothing really went wrong (except getting separated a few times but hey, that's part of the festival). Probably one of the best times I've had at a festival, at least with my limited experience.

The totem helped tremendously. We had another totem which was just a Minecraft torch light with LEDs stuck up inside the tip. Two totems are definitely better than one, it reliably helped keep our group together, despite all the tens of thousands of folks at the event. Even when we got separated it wasn't too bad, and I was able to reunite with some friends later at the event just by holding the totem in the air. (One of the best feelings is meeting your buddies again after losing them at an event... just because there is no guarantee you'd see them again, and yet, you did!)

During the daytime the totem does not really shine much at all. Its just a clear acrylic panel. I had multiple people ask me what the heck it was when we'd arrive at the still-daylight event. Somebody even thought it was a radio! But, when it becomes dark it really shines. The design is simple and easy to recognize, and the whole totem is super lightweight! I have some modifications planned in which I'll update this Instructable. For one, I want to add a foam shield that can clip onto the steel rods that makes taking off the foam easy. And another mod I have in mind is a phone mount so I can record videos really high in the air.

The seed thought that enveloped into this project was actually my friend Haley who complained about a totem messing with her view. I realized I could build a completely clear totem that would not obstruct anybody's view, with replaceable designs. Glad everything worked out well. This is perhaps one of the most "finished" projects I've done, but, I still have a few revisions planned.

Thanks for getting this far into the Instructable! I really appreciate it, this is my first one, despite having been using this site for 12+ years.