new build opinions required

[george uk]

I will put it in sketchup, as my current build of typhoo boxes and cartons and kitchen items, looks a bit to heath robinson ( I can write the Math on them, makes it easier to visualise stresses )

Of all the point you mention above, i think resonance is the one i can not design around, but, If the rails art fixed hard, the bearings will take out some. And although my design may increase the occurrence of resonances, it also reduces the requirement of weight of the gantry, therefor, having less effect ( less mass to carry the force of the resonance beyond the barings ), and also lowering the inertia problem

My works table is within the box of the frame ( half way ), the Y ganrty will be the top of the frame, not above. To keep forces and resonance down, my Z does not extend beyond the gantry frame. only the tool.

My z, will be between the two Y walls of the ganrty, fixed to both walls, the gantry, is a box itself, ( 100/150mm deep - 40mm wall width ), giving me the gap in the center to fit the Z gubbins