Next up was assembling the X and Y stages. These stages are stacked on top of one another. This configuration does lead to some tolerance stacking issues when squaring the build plate to the Z axis. I will cover that more in a subsequent post.
The Y axis stage was fastened to the linear bearing blocks with aluminum spacer blocks in between. This spacing provides just enough clearance for the X axis motor and lead screw. I wanted the X and Y axes to be seated as close to the table as possible because as the further these stacked stages are positioned off the base table, the more vibration and tolerancing issues will occur. In the center of the image above, you can see the anti-backlash ACME nut mounted to its respective block. All through holes for screws are counter bored in the Y axis plate to allow for enough clearance of the Y axis linear rails. On the left is the bearing mount block and on the right is the NEMA 23 stepper motor mount.
Once the Y axis stage was secured, another matched set of linear ball bearings were attached. The spacing of these rails is much smaller than the X axis rail spacing. This decision was a balance between the stability of the build plate (further apart = more stable) and the axis maximum travel. The Y axis carrier block is fastened to the two rails and the build base will be attached to this block. The X axis NEMA 23 motor mount and bearing mount block are fastened directly into the aluminum table.