Trouble with gcode

I'm having trouble keeping my print head from ramming into the platter after I generate gcode with slicer.
Below is a few lines.
I see the nozzle is lifted to 5000 ?? (line 5) but then after heating goes to 0.2 and rams into platter. Is there somewhere where I can make sure all units are the same ??.


; generated by Slic3r 1.2.9 on 2015-12-16 at 18:28:02

; external perimeters extrusion width = 0.50mm
; perimeters extrusion width = 0.58mm
; infill extrusion width = 0.58mm
; solid infill extrusion width = 0.58mm
; top infill extrusion width = 0.58mm

M107
M190 S65 ; set bed temperature
M104 S195 ; set temperature
G28 ; home all axes
G1 Z5 F5000 ; lift nozzle <---- here nozzle is lifted

M109 S195 ; wait for temperature to be reached
G21 ; set units to millimeters
G90 ; use absolute coordinates
M82 ; use absolute distances for extrusion
G92 E0
G1 Z0.200 F7800.000 < --- when this line is executed, the printer head goes below the platter ???
G1 E-2.00000 F2400.00000
G92 E0
G1 X51.957 Y65.193 F7800.000

All units are the same... mm

The 5000 that you saw was the speed, not the position. Actual position is 5mm (Z5).

G1 Z0.200 F7800.000 means go to height 0.2mm, as fast as possible (I'm assuming that 7800 is the max speed). You might want to reduce your maximum speed and acceleration settings in Slic3r if this causes the nozzle to actually hit the bed.

And if the above is no good simply adjust your z end stop to the right height.

Thanks for the advice. I did play with the F7800 and slowed it down....that seemed to do the trick. I suppose it was gettting there just a bit too fast. thanks again