Hi, First of all, I have a Mendel printer with RAMPS 1.4, my current Z axis is the old style with the belt that drives both threaded rods underneath the printer. I plan to upgrade to the dual motors mounted up top as soon as I can make some semi accurate prints. I am using repetier with repetiers firmware which I believe is a modified version of sprinter. I'm currently having problems with my Zby osirase - General