Robot Arm 3D Printer

Hi everyone,
I have started working on a project about a 6 axis robot arm that can print through a FDM nozzle.
For the project I have thought to use TinkerKit(a very cheap robot arm with servo motors with 6 DOFs). My first question is this one:
Servo motors are controlled though rotation angles, but as you know a 3D printer works with GCODE (x,y,z coordinates of the tool), so I have to convert x,y,z coordinates to joint angles (inverse kinematic) that is very heavy to do with a 6 DOF robot arm. Is There a software that can parse the GCODE directly to drive servo motors? I have read about GRBL but it works with 3 DOF (no rotations). How can I do this? Is there another robot arm that uses a software GCODE compatible? Thank you for your help.