I think Sean Bradley built one and thats how I got the idea for neopixals and adafruit. He vacuum formed the blades and I originally started with same process but didn't like how they glued together. Im sorry but I don't have step by step pictures but would be glad to assist with info. I made a wood form of a single blade (one side of energy sword). I placed a 3/8" shallow groove along inside aspect. Neopixals are on a strip that is 3/8" wide. After the form was complete I made a mold of it using products from smooth on. They have multiple types of silicon. I used the beginner stuff. Worked fine. I then used a clear epoxy, also from smooth on, to cast the blades. I used a moldable epoxy to sculpt the handle. The inside was hollow to hold the electronics. Sadly I could not fit the battery inside and still make the handle comfortable. It actually worked out better to use the usb port and a portable phone charger as it went strong the entire weekend at Dragoncon without needing a recharge. The arduino micro controlled everything easily. Programming is a learning curve. I just modified one of the test programs that adafruit provides. The light strips click in the inside aspect of the blade facing towards the edge of the blade. This helps avoid hotspots from the lights. Some simple wiring in handle and your good to go. I made 3 swords originally and planed on selling the extras at $350-400 but ended up giving the extras away as a christmas gift. It is an expensive build. The mold making materials alone will cost over $120. I think I had invested $800 by the time I got it right. A lot of trial and error. After molds are made you can make as many as you want however and the cost goes down significantly. If a group went in together it wouldn't be as bad if making several energy swords. I think cost for materials not including mode making etc.. would be around $150 (2 meters LED strip 60 neopixals per meter, arduino micro, on off switch, and the epoxy for form the structure). Having built the one I have if I was going to mass produce I would make a few changes to make getting the blades balanced easier and maybe figure out an internal power structure. Hope this helps guys. Have fun building. Feel free to ask questions if you want.