In Star Wars lore, the lightsaber is more than just a weapon; building one is a symbol of a Jedi’s connection to the Force. To that end, Jacob Uy, Madison Tong, and Aaron Codrington of Needham, Massachusetts — better known as HeroTech on YouTube — set out to create the most iconic weapon in the Star Wars universe and managed to successfully achieve that goal using some out-of-the-box thinking and some off-the-shelf hardware. “Our main challenges were clear,” Jacob explained in the project video. “We needed a fully contained blade extension and retraction; a compact, to-scale hilt design; [and] a realistic blade and sound.”
The DIY lightsaber can extend and retract its blade at the push of a button, just like in the movies, and features a brilliant LED blade complete with authentic sounds. The saber was designed using high-powered chip-on-board (COB) LED strips, throwing off enough light to see the blade in sunlight. The LEDs are affixed to a springy aluminum magician’s cane that can extend to just over 3 feet long and retract small enough to fit inside the lightsaber’s hilt. The LED strips loop around the tip of the cane, which provides a solid look from all angles.
The hilt is designed to scale, mimicking the dimensions of Anakin Skywalker’s lightsaber, which is around 2 inches in diameter. A circular spool design was designed to store the LED strips inside the hilt when retracted, along with rotating bearings at key contact points to keep them from fouling. A metal geared motor with a 1:90 gear ratio controls the extension and retraction of the blade, while a Xiao RP2040 MCU, paired with an Adafruit motor driver, handles the motor control.
The engineers also equipped the lightsaber with a Proffieboard V3.9, a special sound board found in other custom lightsaber designs, to handle blade ignition, retraction, and additional lightsaber sound effects, which can also be customized to the user’s preferences. The entire lightsaber is powered by a four-cell 14.8V LiPo battery that’s also housed within the hilt, which is 3D printed using ABS material.
The result of HeroTech’s lightsaber design is an impressive accomplishment carried out by a team of dedicated engineers and Star Wars fans, which not only looks authentic but operates just like those in the movies.
We also had a chance to interview the engineers about their design and what may be in store for the future:
Do you risk damaging the LED strip after repeated extensions and retractions?
There is a risk for sure; the original LED strip we used had external solder joints every 0.5 meters, which was a definite point of weakness for the design. We’ve made a couple of changes, including sourcing a new LED strip from a different supplier that does not have the solder joints and instead has a continuous flexible PCB along 3 meters of length. We’re also testing changes to the design, like a larger blade tip (to reduce that sharp change in the angle of the strip) and a softer material in contact with the LED strip itself, all to reduce stress on the LED strip. Definitely something that we’re still working on!
Are users restricted to one style of lightsaber hilt due to the hardware space requirements, or can it be adapted into other styles that may have a thinner or tapered design?
With the hardware space requirements, we’re really utilizing all the space available. Any lightsaber hilt design without excessive tapering is possible with our current style. While we’re working to make the whole assembly even thinner, a thin-neck hilt design might be especially challenging since we have to route the magician’s cane and both sides of the LED strip through it. One possible solution would be to place the magician’s cane at the top section of the thin-neck design; meanwhile just the LED strips can route through the thin-neck.
The hilt is seemingly larger than 2 inches, was this due to all the components that needed to be added?
The base hilt diameter is just under 2 inches, the parts that stick out (the little greeblies, bunny ears, faux black rubber T-grips) are entirely cosmetic, and they’re the parts of the hilt that extend past the 2-inch mark. It was definitely a challenge to fit all the components in that space, and we’re still working to make it even thinner. We have a few redundant components that we can get rid of if we write up the firmware of our Proffieboard to recognize inputs from our additional switches and output accordingly to our motor. Changing the materials of the internal structure could also help us shave off a few more millimeters. Right now we’re using FDM-printed ABS but looking to switch to MJF-printed Nylon for better mechanical and thermal resistant properties.
Can the speed of the blade be increased, or would that damage the LEDs or other components?
Testing an increased blade speed right now actually! With the increased speed, we’re anticipating a higher chance of damage to the LED strip, which is why we’re looking into more ways to make it robust and keep the electrical connections safe. We’re also facing a power density problem since we need a higher-power motor (and corresponding higher-power battery) to increase the blade extension speed. But a higher power motor and battery combo increases the size of the hilt, so we’re looking at different ways to keep the hilt small while increasing power output.
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