Hello. I use a Mendel90, Reprap 3D-printer. I've build it my own for about a month ago. It did work great until today. As you can se in the picture (10447733_10202363158264493_9084480523417671990_n.jpg) it starts to move abit to the right after each layer, and i cant figure why. I use Cura for MacOSX to create G-codes. I've even tried to change computer or try to print any other object, but its still the same. I would appreciate if some one know what's wrong and could help me.

Thanks
Mojt