This is for a taller Z axis, 120mm, and to use HGH linear rails to eliminate movement on the spindle and spindle mount.

to use this take off the current X carriage and take the Z carriage off as well, mount a 20mm HGH rail onto the aluminum extrusions, I used this one (you will need to cut a small section off the end): https://uk.vevor.com/linear-guide-rail-c_10531/2-linear-rail-hsr15-300mm-rails-4x-square-blocks-cnc-set-bearing-smooth-motion-p_010241051268. after this, you can add the print onto the linear rail blocks and then bolt it on, make sure to use M5x28mm bolts max, and M5x24 min. then you can add 8mmx120mm linear rods and 8mm lead screw lead=4mm, pitch=2mm, I used these: https://www.amazon.co.uk/sourcing-map-Stainless-Copper-Printer/dp/B07QYLVRYG, https://www.amazon.co.uk/sourcing-map-Lathe-Round-Length/dp/B07T22Y36C. after this you can put it all back together, just make sure to pull through some slack from the cables as they will be just long enough.