Main Content

Hi everyone, today I’m going to show you how to make a fantasy sword that glows using embedded Neopixel style LEDs. I must admit that I did not really have a reason for making this, other than I just felt like having a glowing sword. I’m a big ol’ nerd okay. Anyway, hopefully someone else finds this useful as a part of a costume or prop.

The sword is about 33 inches (~84cm) long, so it should comfortably work as a one-handed sword for adults, or a two-handed sword for children. I should note, that, due to the electronics, the grip is slightly thicker than you might expect. It’s dimensions are 41x46x120mm. The bet approximation to this is 1-1/4” PVC pipe. The thickness should be comfortable in adult hands, but if you’re planing on building this for a child, you might want to check with some pipe first. The upside of this is that the grip makes up the majority of the sword’s weight, keeping it surprisingly well balanced.

One of my overall goals with this project was to keep the sword almost entirely 3d printed. Since 3d printers are fairly cheap and easy to use, hopefully this makes it easier for you guys to make one. Likewise, it makes it easier for me to adjust the design and make new swords, if I feel so inclined :).

I’ve also included a scabbard design to hold the sword on a belt.

Please note that the sword edge not sharp, but it is hard; it’s not intended to be swung at anyone or used in serious mock combat. Doing so may cause injury and also possibly damage the electronics.

All the files you need (minus the custom PCBs, see Supplies links) can be found at my Github: here.

A brief overview of the electronics:

The sword uses SK612 3535 led strip for lighting. SK6812’s are essentially the same as the more ubiquitous WS2812b LEDs (aka Neopixels). The reason I chose to use them, was because, at the time of assembly, they were the only WS2812b compatible LEDs I could find on strips at 3535 SMD size. At 3535 SMD size, the LEDs are just 3.7x3.7x1mm, much smaller than the WS2812b’s 5050 size of 5x5x3.5mm. This meant I could fit more LEDs in the sword, while also minimizing the blade’s thickness. The LEDs are controlled using an Arduino Pro-Mini mounted to a custom PCB, while the sword is powered by an 18650 LiPo battery. A single push button is used to control the LED effects, while an optional potentiometer controls brightness.

Overall, I’ve programmed 25 different effects for the sword (as displayed in the video above). Please note that for a lot of the effects the colors are chosen at random during runtime.

Finally, if you have any questions about anything in this instructable, please leave a comment, and I’ll get back to you.

Custom PCBs:

To keep everything compact, you’ll need to order a couple of my custom PCBs:

One Pro-Mini Cosplay Board Mount: Found here
One Flat Tactile Button Mount: Found here
If you’ve never ordered a custom PCB before, it’s easy. I briefly go over it in Step 2 of one of my other Instructables here. As with that Instructable, all the ordering defaults should be fine for this project.

Electronics Parts:

(You might be able to find most of the parts for lower cost at places like Aliexpress, Ebay, Banggood, etc)

2M of 144 LEDs/M SK6812 3535 (mini) led strip, non waterproof. Found here
One 5v Arduino Pro-Mini (available in two pin styles, either works) Found here. For the curious, you can read about why I use a 5v Pro-Mini over a 3.3v version in step 1 of one of my other Instructables.
One 18650 LiPo. Any type will do as long as it can do 4A output. Can be with or without protection. The one I used can be found here.
One 18650 over current protection board (if not using a cell with protection circuit pre-installed). Can be easily found on Ebay, any with a 4A cut-off will do. The one I used can be found here.
One TP4056 1s LiPo charging board. Found here.
One Flashlight style push-button. Found here
Four 3 pin JST-XH 2.54mm female connectors. Found here
Five 3 pin JST-XH 2.54mm male connectors (one for making test probe). Found here
One 2 pin JST-XH 2.54mm female connector. Found here
One 2 pin JST-XH 2.54mm male connector. Found here
One of each 0805 size 100K resistor, 1K resistor, and 1uf capacitor. Found here, here, and here.
(optional) One Bourns 10k potentiometer (3310C-125-103L). This is used for brightness control, and can be omitted if you prefer. Found here
Copper Tape, 1/4”. Found here
Seventeen JST-XH crimp terminals (although you should buy spares). Found here
One 6x6x13mm tactile button. Found here
22Ga stranded wire, at least three colors.
26Ga stranded wire, at least three colors.
3mm diameter heat shrink tubing.
2.54mm male headers.
Three Dupont style jumper cables with a male end (for testing)
FTDI Programming cable. Found here, although other types are available on Amazon for less. You can also use an Arduino Uno as the programmer (if it has a removable ATMEGA328P chip), see a guide for that here.
Other Parts:

(most of these items, asides from the 3d print filament, can probably be found at your local hardware/craft store)

Transparent 3d printing filament and a filament of any other color (if you want to conserve the transparent stuff)
3/8” x 36” square/round wooden dowel. Found here
Spray paint in the color of your choice, I used Ace Hardware brand antique gold found here, but any other dark-bronzeish gold paint should probably match.
Spray gloss varnish paint. Brand probably doesn’t matter, I used Rust-oleum Ultra Cover Gloss Clear found here.
Rust-oleum sandable filler primer spray paint found here.
(optional) Krylon Glitter Shimmer Opulent Opal spray paint found here. This is basically a clear glitter spray I added to the sword blade to give it some sparkle.
Krylon Glitter Blast spray paint in the color of your choice, found here. This is for the gems on the sword blade. It’s like the Glitter Shimmer paint, but includes color along with the glitter. I did not actually use this for my gems, I air brushed them with a pink/purple acrylic mix, but it should be about equivalent.
Two 8x10mm and one 6x6 acrylic rhinestones in the color of your choice, found here. These are used on the sword hilt. The ones I used are very old, so I don’t know where I got them, but the link I provided should be about equivalent.
Two 90mm lengths of M3 threaded rod, found here.
Two M3 locknuts (nylon insert type) found here.
Two M3 6x0.5mm washers found here
Bondo Glazing and Spot Putty or gap filler of your choice. Found here
Aqua Coat clear wood grain filler. Found here

3D printer
Soldering Iron w/ fine tip and solder
Wire strippers/cutters
Hot glue gun + hot glue
Super glue
5.5mm wrench (for M3 nuts)
Sand paper (150, 220 grits should be fine)
Some kind of strong glue (epoxy, contact cement, etc)
Sculpting tools/spatula for spreading Bondo
Heat gun (for heat shrink)
Tweezers or small pliers
Masking tape (the wider the better)
Crimper for JST terminals, found here”

Link to article