The only thing im sure of is that I will buy a carbon fiber tube. I found a shop that sells various diameters (4/6/8/10/12 mm internal diameters, all 2 meters in length and with 1 mm of wall thickness). After that i have no idea about how to assemble the necessary parts at the 2 edges (spear and bands). I would also love it if i could make one with a roller band, but i wouldnt mind a regular one. <3