Wierd problem!
Hello! Anyone have an idea of what is going on?
If I print one of this cases, everything goes fine. But if I print two or more, the wall with one case face the other will be ruined. Some line appears loose from the wall in one case, and a "negative" image will appear on the wall of the other case. I´m using the normal profile for ABS of the Original Prusa Mk2. 
RE: Wierd problem!
Are the metal rods smooth, do not have the grooves inside? If there are scratch, turn the rod 1-2mm. Maybe help
RE: Wierd problem!
Good idea! I will check that! Thank you!
RE: Wierd problem!
Just an idea - but when two parts are close together, they radiate heat to each other and also the part in front will block airflow. If you haven't done so, try placing the two parts so they are side by side instead of front to back so the print cooling fan can get air to both parts equally.
RE: Wierd problem!
Found the problem! The screw which holds the holder of the belt of the BED was loose! Now is printing perfectly! 🤗