Fire Force: Arthur’s Excalibur

My cousin Jason is cosplaying Arthur from the anime Fire Force. He asked me if I could model and 3D print his signature weapon: Excalibur!

Motivation

https://vignette.wikia.nocookie.net/fire-brigade-of-flames/images/f/fa/Excalibur.png/revision/latest?cb=20190326054506

My family and I all love anime and we recently watched Fire Force. It’s a pretty popular anime that got tons of advertisement on Crunchyroll, an anime streaming website.

There’s a main character in the anime who goes by Arthur who’s a dorky fire-fighter in training. He may seem silly at first, but once you get to know him more, he’s actually incredibly talented. He fights with his signature weapon Excalibur which is a simple handle that emits an extremely powerful blue flame. It works similar to a lightsaber from Star Wars.

Make this like a light saber.

Since it’s basically a glowing lightsaber-like weapon, we knew we had to include LED’s into it. The blade has to glow a bright blue to really put on a convincing cosplay. I modeled out the entire sword first, and then cut in channels on the inner part of the hilt to accommodate the electronics that will power the LED’s in the blade.

I modeled the handle to split into two halves so it will make installing the electronics portion much easier. The handle is held together with 5 self tapping steel screws. In a future iteration of this, I would like to revise this to be held together by M3 threaded inserts and screws so that taking apart the handle over and over again isn’t going to damage the mounting holes.

In order to get a nice seat of the blade into the sheath, I modeled in little rectangular slots on the end of the sheath and handle to hold little neodymium magnets. These magnets don’t have to be incredibly strong, but it should be enough to hold the blade to the sheath.

The Blade

The blade is completely hollow in order to allow the LED’s to fit inside. We went with generic WS2812B LED strips on Amazon with an LED density of 144 LED’s per meter. We wanted to get an LED strip with a high LED density so that the blade doesn’t end up with hotspots. It should be one continuous glowing blade.

Since the entire blade is hollow, it’s going to be tricky to glue the pieces all together. I designed the ends of each blade piece with small peg inserts to hold it in place. This should allow enough surface area for the 2-part epoxy to bind to.

The pegs go into the inserts shown on the right side of this picture.

The electronics

The electronics of this is really similar to the Adafruit Guardian Sword++ build.

I’ll be using:

Adafruit Trinket M0
3.7V 2200mAh Lipo battery
Adafruit Lipo backpack
Generic slide switch
2x Generic WS2812B LED Strip 144LEDs/meter

Adafruit’s circuit diagram is incredibly clean and detailed so I’ll paste a screenshot of it here.

https://cdn-learn.adafruit.com/assets/assets/000/041/583/original/leds_circuit-diagram.jpg?1494339824

Here it is all wired up and programmed. It’s a rat’s nest but it works.

Printing Excalibur

Printing Excalibur wasn’t all that difficult, but it did take quite a long time. The blade and sheath were both printed standing straight up since I wanted all sides to have a uniform look. If I printed them all flat on one side, the side printed against the bed would have a different texture as the other sides.

I printed the entire thing in PLA. I used a green PLA from eSun that I had already loaded up on my Prusa. For the blade I used "Natural” PLA from Solutech. Natural PLA is PLA without any pigment, so it gives it a sort of hazy transparent look; perfect for what we need.

The final mock up before I start printing.

Here’s Excalibur fully glued together and me for scale! This thing is looooong. It stands just over a meter tall.

Sanding, Painting, and Full Assembly

I’m leaving the sanding and painting job to Jason. He’s going to filler primer the entire thing and sand it smooth. I’ll be updating this page once it makes more progress.

Stay tuned for more updates! To be continued!!