Well I can say that failure is expected but not the preferred mode of operation.
I would assume the internal air pressure not to exceed 200psi of air as I am trying to get away from the 400 psi pressures of the air bags.
That would put each 8" tube at approximately 9000 lbs assuming a 1-1.75 shaft diameter.
ideally safety parameters don't need to be 3x but thats what I strive for. Each "section" would have an aluminum or composite end plates (or combination) secured on 4 sides.
Its likely I don't have the weight to do it but the present bags are approx. 11lbs with the end plates being another 7-11lbs each.
So right now my system is approx. 25 lbs. Side loading shouldn't be an issue as a linear guide is employed to keep the shaft perpendicular to the base.
(sorry I have to be vague as I am away from my bot right now and just using cad estimates).
Custom (not of the shelf) would work as well its just a last minute change out prior to my May competition.
Thanks JC