Inspired by https://www.thingiverse.com/thing:3606120, but needing a slightly different design, I designed this working[*] light saber for my son, Theo, for his 2019 Halloween costume. Designed after Luke's lightsaber from Return of the Jedi, the Theosaber is an elegant prop for a more civilized age.
The handle is designed to mate with the end cap, which is held in place with two set screws. The cap has room to hold a 500 mAh LiPo rechargeable battery, or a 9V battery. The handle has room for a power button, rotary switch (e.g., to control color or brightness), and an LED module. Instructions on building it out below.
[*] Well, it lights up.
Supports are only needed on the "emitter" end of the handle - the rest is designed to print without supports.
Here is how I built the complete lightsaber based on this handle design.
The blade is a 1" OD plexiglass acrylic tube, frosted, ordered from eplastics.com:
The power buttons are from Ulincos:
The color selector switch is a mini 8-way rotary switch from Adafruit:
Battery is a 500 mAH LiPo:
The LED module is a Luxeon Rebel Tri-Star LED module, with red, green, and blue LEDs:
The wiring diagrams for these parts are self-explanatory. The battery runs through the power switch, which connects to the Vcc input on the three LEDs. The ground for each of the LEDs is routed through the rotary switch back to the negative terminal on the battery. To simplify assembly, I use JST SM connectors between the battery, power/rotary switch assembly, and LED module.
Use set screws to hold the end cap to the handle, and the blade to the handle. I use M3 screws with heat-set inserts to secure them to the handle.
3.7V is more than enough. These LEDs are incredibly bright. With a frosted plexiglass tube you will get decent light diffusion through the blade.