Nice Idea - but you spend a much of the way to m ove to the 45° strut for the portal ( is that much necessary???) another thing - the "hinge " to the X spindle is very stable in z direction - not to carry load due asymetric load on the portal... After you have this really wide distance of your X sliders - why not constructing a kind of plate under the moving parts to install the x axis spindle would work as crosstruts and would give much more stability....
understand what I mean?
Hansjoerg
Why reach for speed, when you could have precision instead!!!