A coworker walked into the breakroom today with two heavy cardboard tubes. One was about 2' long and the other was about 3' long. Same diameter. They were originally what the plotter paper was spooled on. I wasn't sure why he was giving them to me until he said "rocket tubes, I got them from my plotter paper roll". Then he left I took them home and measured them... 50mm ID, 55.3-ish mm OD. I'm thinking about 3D printing a nose cone and adding fins...maybe try to fly it on some of the G motors I have stocked up. Or an I nah...