Cnc router gantry design

hi all
iam about fo finish my cnc router frame build,but now iam stucked in the gantry
I am now faced with two options
usign :
1- one shs square tube 120mm
or
2- two shs squaretube 90mm brazed together

the max shs dimention i found in the market is 120mm square.

my mind goes for the second choice beacause i have alreday the shs 90mm ,plus the advantage the space between the linear rail would be large enough

any suggestion is welcom and thenks in advance


This is a companion discussion topic for the original entry at https://www.cnczone.com/forums/mechanical-calculations-engineering-design/466456-cnc-router-gantry-design-new-post.html