Paying job has been keeping me busy, but I have made some more alterations to the design to get to the state in the diagram attached. Actually I'm going to go with double thickness (60mm) for the four "corner posts" on the bed/frame and also thicken the T-Slot bed to 30mm even though the bed will be supported in 4 places.
Still not sure about the configuration of the Z Axis, as I see using a belt/pulley arrangement with linear rails and the stepper mounted to the side opposite to the spindle seems to be the accepted "strong" option. Also ignore the spacing of the bearing blocks as that will change or be replaced if I go with the arrangem,ent in the last sentence.
Questions (there seems to be more and more):
1. For the X Axis and from other posts I am guessing that when ordering ballscrews and assuming that I will be mounting the bearing/support blocks on the outside of the "corner posts", I need to order a 1605 ballscrew that is 1081mm with standard machined ends (total length of frame is 1,000mm currently) i.e. for 1605 its length of screw thread plus 81mm (30mm+39mm at the fixed end and 12mm at the supported end).
2. The BK blocks appears to be an FK mounted into the BK block housing, so if I order Chai's standard 1605 package, then will I be able to take the FK out of the BK block and use it in say an MBA-12C motor mount from somewhere like Zapp?