Irving,

'Y' ?? it's the Z that will be the most worrying, The design as pictured in the .pdf uses 40X80 extrusion I am using 45X45 but where the original has a 45deg brace using a section of extrusion, I am going to use triangular aluminium plates (something like 300 X 500 X I cannot remember my geometry for the longest side). I am thinking of using the space within the two plates for something, just not sure what!! The motor for the Y axis is mounted to the rear of the machine.

IGUS rails and carriages are being used along with Trapezoidal Screws etc, EMC2 as the software (software backlash compensation) wood chips and dust being my problem rather than hot chips and coolant.

There will be 1 Mt long (approx) 'outriggers' fitted to the front and rear 'legs' with levelling feet at each end + the two centre legs will also have feet.

The reason for the height of the Z structure, is to be able to raise and lower the whole Z assembly in one block thereby allowing me to have a 'tall' workpiece but still keeping the Z movement to a minimum.