I'm designing a 10in f/6 truss Newtonian as a sort of big travel scope; something that I can break down into parts to fit in a backpack or similar but will still give me decent angular resolution. In trying to optimise for portability, I've managed to fit the rocker box, base, secondary mirror and cage, etc into a nice, small, portable package - but I'm stuck with eight 20mm diameter, 1.5m long truss tubes to carry around. Using carbon fibre the mass is no problem, but the sheer size would make transporting it completely impractical. Does anyone have any techniques they've used to solve this problem? Of course, there's always the option of cutting the tubes into multiple parts like a tent pole - but I worry that would seriously affect rigidity and add major vibration.
I have two options, but the experts might not like them.
The first is to replace the carbon fiber poles with telescopic tubing similar to that used for camera tripods, but maybe a bit more robust.
The other option is to cut the poles into two or three segments. It would be preferable if the ends could be shaped into, for want of a better description, "dowel/pin and socket joints". One end has a ciruclar square, triangular or hexagonal hole in it and the end of the joining segment has a circular, square, triangular or hexagonal dowel/pin cut into it so it fits neatly into the hole in the end of the other segment.
Whether or not the mating joint is possible or whether only perpendicular cut ends are possible, brace the joints with curved plates that wrap around the rods/poles with two plates encasing each joint. Ensure the internal diameter of the plates matches the diameter of the rods. Ensure there is sufficient overlap of the curved plates over each joint to enable two or three bolts on both sides of each joint to secure the plates and sandwich the rods between them. Whether you use nuts and bolts that require a spanner to tighten them or whether you use butterfly nuts I leave that decision to you. Having washers bent to the outer diameter of the plates might also help.
As an after thought, if you didn't want to have the joints secured by two plates, a coupling sleeve could be used instead. This would simply be a tube whose internal diameter was just slightly larger than the diameter of the rods, but it would be bolted to the rods in the same way.