Some conclusions about it:
I used plastic letter trays, I sanded it with a metalic brush (what a work !).
The plastic letter trays were cutted with a soldering iron.
Each letter tray has an "entrance" that I made with the soldering iron so a roach can go from a letter tray to another.
---------- A bad point:
I putted them vertical because when the roach is vertical on the wall it poops towards the ground.
That way in teory will create a distance between the poop and the roach
(I think that is the teory about putting the egg crates vertically and not horizontaly)
So what is the problem ? Well...even hard sanded plastic is hard to climb.
Only Insignis climb it well and small Princisia roaches.
Altough a small Princisia roach made it, it seams that it doesn´t do any more because it leads to nowhere (instead of a hidding zone like the cup section of an egg crate).
I think that if I glue a cork panel or a rubber panel it will be more easy to climb.
Why I didn´t used only cork panels ?
Well...they bend very easly and they are fragile, I think that the plastic will make a nice holding frame for it.
The vertical position reduces the area that a roach can move but it allows to create separated sections that males roachs can defend...an open horizontal territory would create to much conflit because it´s more hard to defend.
------------------- Improvements to make:
I am thinking on gluing a plastic horizontal structure between each letter tray so it will make a new floor.
The plastic structure will be a cutted letter tray (with a rion soldering).
The roaches will have a cork panel to help them climb.
I must test the roach ability to climb a cork panel before I implement it.
------------------ Alternative to cork panel
A nice alternative to a cork panel is a sound sponge, it can be glued to the plastic.
And it even has the same structure as an egg crate...but I wonder if it will resist less time than an egg crate...
------------------ Plastic VS plywood:
Plastic is impermeable.
Plastic is more easy to cut (a soldering iron cuts it more easly than a saw cutts a plywood board).
A plastic letter tray is more cheaper than plywood.
But plywood is more easy to climb and it allows for a certain micro-fauna to grow (like the egg crates).