AFTER FIRST LAYER PRINTS IN AIR
PRINTER GEETECH PRUSA I3 ALMINUM PRINTS FEW LAYERS AND THAN CONTINUES TO PRINT IN THE AIR (ABOUT 2 mm) over
Check your gcode for z moves. Z is only moved if you say so direct or indirect.
Where is the Z control. The slic3r generates the code. And there movments in Z by layer hight i geuss
Check your Z movment steps calibration,
home Z then send a G1 Z100 measure how far Z actually does move
Z 100 IN SOFTWARE IS Z100 IN REALTY, WHEN I PRINT I NOTICES THERE IS 2 mm offset for some reason from the value that is shown to acctual value., for example 4 is 6, etc.
and it isn't the z offset value, becuase it is set to -0.5.
Show first 100 lines of gcode not counting comments. As I said if homing goes to z=0 and G1 Z1 has 1mm then it is in gcode you send. If the simple test fails your configuration has a problem.