Hi to All, after testing my Wanhao D6 for several months, firmware Marlin Version 1.1.0-RC8 02-27-17 Version 5.0 I finally realized that the original firmware 3.1 prints better on the first layer.
Surely the Marlin has problems with the leveling system of the plate.
Quite distressed I decided to take the original firmware and enter new menu items in “Maintenance > Advanced” and edit some of them:
Lower plate 25mm
Lower buildplate (the heated plate goes down to the bottom)
Preheat all (Preheat Extruder and Plate “210/70”, status Info)
Stop heating (Extruder heating and flat heating, status info)
The firmware can be installed either by Cura Wanhao or by Xloader included in the zip file.
I hope to have been useful to the community.
Special thanks to my friend G. Orrico.