looking at the mr1 first i was wondering what type of cement you all using .
i used many bag of cement over the years . they not all the same . most lack Portland cement it self
that why the quick create they sell home depot never gets white and super hard . also you using stuff with the rocks in it .
second question i was looking at the manual . looks like the Y axis rails they just sit there . Do not bolt to the lower pan to keep them in place . as the same for the center aluminum cut plate . it all relies on the cement to hold everything in place , over time cement cures it shrinks . As it shrink it cracks . it fact of cement that why expansion joints put in . i might be over thinking the cement part . my main concern is keep the Yaxis in place buy bolt it to the pan . any input on this