Nesting modular tube system to make larger objects without fasteners.

This is the beginning of a modular tube filament system. Each tube is 1.5cm in diameter and I've uploaded a test sized 2cm effective length and a few options up through 18cm effective length. Note the total length is 1cm longer with the inner coupler included. They are also sized to fit most spools as a holder. I've only printed the 2cm tests and the 14cm sized tubes always sliced with KISSlicer.
I'm using large 1kg 3Dprima filament spools and want a freestanding filament holder. These will make the support arms. My current design uses at least four and maybe eight 14cm tubes for the supports.
They are designed to nest without any additional finishing and I suggest making a set of the 2cm as test pieces to ensure they nest correctly with your machine. I'm very new to 3D and my Ormerod1 may not be dialed in perfectly yet, but they fit quite tight for me. If they get stuck together, a slight twist seems to help open them, the longer tubes are much easier to open.
I will be adding a bearing end as well as the rest of the filament design as I complete them. I'll use the same ends when possible in all of my designs where applicable.
The Sketchup file is also included if you want to adjust or modify my designs. Note: I work at 100x scale in sketchup and scale by 0.01 before exporting the .stl file. I do this because sketchup does not always render very small object faces when the model is small. By increasing the size 100x you remove all "small" faces.
Enjoy!
Kimon ~ The Amsterdamman