About Ultimaker 2 and Gcode

[JG87 0]

Hi all!

 

I have a problem, I'm trying to drive my ultimaker 2 with python and I start my gcode with :
send_gcode("G21")
send_gcode("G90")
send_gcode("G28 X Y")

The print head is positioned in the left-hand corner at the bottom and not in the left-hand corner in front. It's as if the G90 had no effect.
What's wrong?

[Slashee_the_Cow 351]

G90 just sets movement values to absolute instead of relative (I don't know about the UM2, but on most printers it's absolute by default). It doesn't affect the home position (G28) at all. The home position is set in the printer's firmware.

[Dustin 144]

well as the print head does not move up and down on a UM2.. im just confused.