Basic design with 40x120mm extrusion for the main axes.
Changed to Unistrut for the Y axis and added some basic slides and a gearbox of sorts, I am not entirely convinced that this would have been vey stable.
Some better slides, based on the ones from CNC Router Parts and a first attempt at a Z axis.
The Z axis progresses a bit further.
A change to profile sides, a better gearbox design and profile extrusion for the Z axis
Closeup of the gearbox design
Slightly more compact Z axis
A second idea for the Z axis
Doubling up on the X axis for additional strength and added a B axis.
Closeup of Z and B
Whilst a nice idea, and one that I may make use of again in the future, the levels of flex with attempting to have a 5 or even 6 axis unit (trunion or lathe on the bed) are just way too much for a Z axis extended this far and this thin.