Z-Axis depth on X-Carve

The 2" z-axis is very very limiting for many of my projects. Curious what modifications others have made to increase the height? I use one machine at a makerspace for teaching and would like to raise the Z-axis about 1/2" to 3/4".

I also purchased a used X-carve for home use and thinking to raise the z-axis for about 4+ inches. Thank you.