One ring to rule them all?

[Rufe0]

Hello everyone
Wonder if I can get your opinions on this?

I think making this out of 100x100x5 tube would be too weak. It would weigh 100kg so making it thicker isn't really an option. I think 150x100x3 would flop around and generally not be very rigid. So that pretty much leaves me with the option of making it in two halfs and bolting it together. Something like this



This drawing is of 100x100x10 with 20mm connecting bits, or 25mm. Each half would weigh 77kg without connecting bits, near 100kg with them.

I'm thinking bolting it together like this, red circles are bolts.



Each connector would be welded at one end to C shapes and bolted at the other. Then they would be bolted to each other.

I don't think it would be solidly connected enough though. I think the 0.1mm better deflection gained from using the 10mm wall tube instead of 5mm would be lost in the less than solid connection between the two.

I think it would probably be fine if the cutting force is straight front to back or side to side but if it's at all diagonal then there would be all sorts of twisting and skewing forces that would ruin accuracy and rigidity.

I'm just struggling to find a way to make the thing really rigid enough and still light enough for two people to carry when disassembled.

Any ideas or thoughts? Thanks