Accurate Strong Gantry

[vargai]

Chapter #2 Fixed gantry

I am back again after aging some thoughts however I could not go too far. I cannot find too much examples for the ideal fixed gantry frame.
Probably I am making the typical mistake and try to reform something that is good as it is.
My viewpoints are:
using hot rolled profile -do not know but think it is better vibration damper than cold formed tubes (SQ or RECT)
using bigger cross sections- to eliminate the bracing and welding as far as possible
setup with 1700 mm total length-just slightly longer than moving gantry

My concern are:

-bolted connection as figure shows-is it is good enough- instead of welding?

-The spindle overhang is quite big -though is fixed in one direction . Is there a better setup to eliminate?

-I would balance the moving bridge on both side with pneumatic cylinders or gas spring that I red here and like this option.
As the spindle moves in Y direction the Center of Gravity moves with it -that seems not too beneficial for the balancing

Figure below shows mainly principles first to make a good machine setup



Thank you for your comments and advice in advance.