the5jfam

Hi everyone, very new to 3 d printing. I have only printed pre-made objects on the SD Card that came with my Ultimaker 2 Extended+. The problem I am having is that after slicing my object to fit on the print bed in meshmixer, I export to Cura and the bottom half of what I sliced lays flat on the printer bed. However the top half is floating. When I put the file on the SD card, my Ultimaker immediately starts printing about 10mm above the print bed just like it shows me in Cura. So how do I get the top half of the file to lay on the printing bed? Please somebody help me solve the mystery of the floating 3D Object so i can start printing things.