Argyri,

Looking good!

The best place to get the Hiwin CAD models is http://www.hiwin.de/en/CAD_Configurator.html

Most cost effective way to get the rails and carriages is to go east. I would suggest that you get carriages with preload so they do not have any slop, it adds a bit to the friction but worth the extra effort.

In order to account for distortion etc I would suggest you build, level and then drill. A hand drill with good bits and a drilling jig like you describe is good as long as you make provision to straighten the rails afterwards. Have a look at installation instructions from HIWIN which is similar to this NSK one for ideas on mechanisms to align and adjust for straightness and squareness, if you haven't already done so.

You could have the top sections on bolts but what would be the benefit if you epoxy level and drill afterwards? From our conversation it seemed that you were not thinking of moving the machine around so stripping it down is not needed. I would have thought that, should you crash the machine, you would need to readjust everything including the rails. In a rigid system, you will potentially only need to readjust the rails.

Regards

George