[pmrid (Peter)]

I've been lingering over a decision to abandon my old hot-water system OTA in favour of a lighter truss design but before going that far, thought it might be feasible to get the saw/grinder out and cut holes in the sonotube to create a sort of truss design. I wonder if anyone has ever tried something similar.
You'll get the sense of what I'm thinking from the attached rough 2-dimemsional image.
It is a Dall-Kirkham scope and the tube has to be 1200 long so I imagine it would need the strength of a central rib section at about 400mm or so. The bulk of the remaining weight in this little project is in the mirror/cell/focuser/baffle assembly at one end (about 12 Kgs) and the secondary/spider assy at the other (about 3 Kgs). The existing tube weighs 12 Kgs and I would like to be able to sacrifice as much of that as I can without losing structural integrity by inducing flexure.

I'm hoping that by keeping the sonitube "trusses" to about 80mm wide and the end and "rib" sections being about 150mm wide.

Any thoughts?

peter.