I was concerned about my Melzi board, when i got the printer kit. So this was one of the firts things i decided to print after i finished the printer. After printing the bottom halft, i found out, that i configured the firmware badly, and that the cover is about 10% smaller than the board, that brought me to tuning of the firmware. The printout after the update is very precise. Thanks for the design. However, i am thinking about editing the top cover in that way that i have possibility to acces the SD card even when the lid is in place.