Thats the only issue with the design, I noticed exactly what your talking about...Well alteast i think haha, The gantry... when adding all the components to the gantry ill have to do so in a certain order...and if say the whole gantry is assembled and i need to removed the ballscrew but then id have o dismantle the whole thing... the only issue i can see.

I will be having the machine welded up then going ahead with the expxy method..