homing Delta Rostock 3gs

[mga]

I pressed home and read the height of the extruder: 207. I reported this value in the firmware and settings Repetier host (print height).
I lowered the probe and the probe centered in the plane when the probe touches the center. I wrote these coordinates and I entered so
#define X_PROBE_OFFSET_FROM_EXTRUDER 17.7 (value read by the probe moved by hand on the center of the plate)
#define Y_PROBE_OFFSET_FROM_EXTRUDER -10.00 (like above)
#define Z_PROBE_OFFSET_FROM_EXTRUDER -0.57 (this value I found working with attempts)
Since I returned 0 I thought it was ok homing.
I tried to print an object. A small object. But the printer touched the floor. I had to stop. Turmoil block can not remember, but perhaps not only touched, but the plan was tilted (at one point touched another but no). I ask for suggestions.
The nozzles in setting are 0,3 in Rostock delta G2s?
I tried to enter a value Z offset (Printer settings / general) in slic3r to see if this is the reason why the head slamming on the floor, but the value that I post is deleted immediately, as if it were not admitted.