Manual extrution works but extrution from file extremly thin

I got my prusa I3 with merlin and have the problem that when I manually extrude (using the LCD control) it extrudes the fillament without a problem but when I make a gcode file and want to print the extrution is extreemly thin.

I must have done something wrong when calibrating the .h file of I'm slicing the 20mm cube wrong.

Does anyone have an Idea what this NOOB is doing wrong.

Thanks in advance. (my kids are bullying me that daddy has a new project he only half finished again)

It could be slicer related.
Nozzle diameter and filament diameter settings should match the real world.

A close inspection of the filament gears is mandatory. ( grubscrews and idler gear pressure )
Vref / stepper current setting and e-step calibration is also neccessary.

Happy printing
-Olaf

Thanks a lot I turned out to be the layer hight setting in the slicer. I set it to 0.2 mm when i put it on 0.4 it worked.