This is a remix with custom parts to 3D print a lightsaber that has a real laser fitted inside.
WARNING!!! This is not a toy. The laser it's made for is very dangerous and will permanently blind you if the beam enters an eye! Even with "star cap" that usually comes with it direct eye contact should be avoided. Please take all safety precautions that you would do with a laser. As the switch button is flimsy and safety lock is open, treat it as if it can spontaneously turn on at any time. Always keep a "star cap" on, except directly before a demonstration (such as shining a beam to the stars - take care to avoid any aircraft traffic). The cap splits and fuzzies the beam and some say makes it relatively safe. Still don't point it to people's faces. Generally be very responsible with it. It's for costume and display purposes only, do not do stunts with it, it can disintegrate. Sorry for the long warning, but please take it seriously and don't do anything stupid. If you decide to build it - do it on your own risk. You have been warned.
Laser type: search for "303 laser" on eBay or Ali. It should have a button on the side, a safety lock with key on the butt, come with star cap (or several), and it should be powered by a lithium 18650 type battery. Make sure to buy a couple of batteries and a charger. Cost with charger one battery can be as low as $10 USD. You can get red (dimmest), green (brightest) and blue (most powerful but dimmer than green). I suggest green as it is brightest of them all. Blue is twice as powerful for the same or less brightness, so I think there is no need to make it more dangerous than it is. 303 laser without cap will shine a visible beam at night over several kilometers. You can point the stars and constellations in the sky and illuminate a treeline over the lake etc. Again, be very careful, never use close to other people.
External parts are combined from different remixes (I printer the wrong body parts so had to glue them, but included correct ones that should be screwed on both sides). Internal parts are hollowed out and new ones are created to fit the laser. In my experience printing with Tevo Tarantula I had to file some plastic off and make all kinds of adjustments post-print to make everything fit correctly. Some parts are glued together with AC glue or superglue. So it will need some tweaking after you print it. I have made a small foam cushion wrapped with aluminum tape to serve as a spring to push laser up. Small spacers are there to be glued to internal cup for it to fit better if needed. They may not be needed with the parts provided, or can be scaled to provide the distance you will need to cover with your particular printer. Look at my photos, it should be clear what goes where.
There are two versions of an internal firing cap - one that has slot for the laser button to go in and serve as a retainer so the laser won't fall out. If you want the slot to go all the way you might want to cut the plastic between the slot and the button hole. I did. But the cap was too flimsy after that so I had to reinforce it. So I think it's better not to cut it, there should be enough room for the button to squeeze by. If you want not to have a slot at all - there is a part with just enlarge opening for the laser diameter, without additional slots. You can customize it.
Once assembled, measure where the laser button is, and if everything has worked out, you need to drill a hole exactly where the top button is supposed to go, use provided button model, tape button from inside so it won't fall down, try it, make sure it's working, then measure the button part that's sticking out and scale faux button parts to glue next to the functional button.
I have painted it with acrylic metallic paints using wet and dry brushing technique for aged metal look. Printed in black and red PLA.