Modular cylindrical container / Poster tube

I need a poster tube for conference poster, so I made one that can be easily printed and assembled. Now I use it to store long materials.

The idea is to print single sections with vase mode (with or without bottom layer) and assemble them by the thread. There are three different basic elements:

tube without reinforcement: it might collapse and bend sideway, but you can attach the ring attachment in any section of this tube. 

tube with reinforcement facing inside: the tube will not collapse not bend, and can be freely attached with the other two types and the ring attachment

tube with reinforcement facing outside: the tube will not collapse nor bend, and can be freely attached with the other two types. Not compatible with ring attachment. Can be used to connect two inside-reinforced tubes. 

It is recommended to print with vase mode (1 parameter, 0% infill). Do not use first layer except for the bottom and top element. 0.1 or 0.15 layer height is recommended, too large layer height will cause issue in layer bonding. With default prusa filament & print setting, the print can be accelerated to 200% speed without problem. Or you can accelerated by removing minimum layer time in filament seting.

Important: If you print the first part in 100% scale, it is also important to scale down the adjacent part so the inner thread of the first part can fit the outer thread of the second part. If you use 0.4 mm line width, it is recommended to scale 98.5%. In case of other line width, the scale factor can be calculated as f = (65-2*line_width)/65. Only scale X&Y, not Z. You can then alternate the 100% and 98.5% part to create infinitely long tube :)