normoldboy:
Another concern is that if I put thread lock on all of the bolts, levelling the sliders later would be a nightmare. Is there a written procedure for levelling the interior mechanics before.
Thanks, Norm
I would go ahead and use the thread lock and worry about alignment later. The rails fit pretty snug and you can't do much about the alignment of any individual rail. You will have to align the X axis relative the Y axis later, but this is performed by making adjustments to the belts and pulley gears, not the rails.