I finished the hard disk structure:

I started polishing the edges of the “slides” and the structure:

then, I began to assemble the structure:

and I made this holes, to insert the screwdriver when I mount the hard drives:

I reduced the thickness of the slides, to mount easier the hard drives:

then I mounted the finished slides on the structure:

I mounted the hard drives:

and the structure completed with two dummy hdd mounted inside: