GRBL + Adafruit Shield for Lasercutter

Ciao a tutti!

I've got some problems running the GRBL Software

together with my Adafruit Motorshield.

Now I've tried to find something about it in the internet, searching in both, the GRBL config.h and pin_map.h and the official adafruit Shield Library, but I can't get through it.

I want to use the shield to controll two Stepper Motors for the x-axis and the y-axis,

but GRBL in "the plug'n'play" configuration can only work with two drivers for each Stepper.

I hope someone could help me, because my whole project stands still and it's really important for me to get it ready.

Thank you and many greetings from Austria
Kruzius