Calibration not completely accurate in z-axis
When reaching for points on the print bed which are further away from the robot, the tip will get closer and closer to the bed until it is touching. When reaching for points on the print bed which are closer to the robot, the tip will be further than desired from the bed.
This could be due to one or more of the following:
- the robot leaning forward under its weight when reaching forward
- the calibration pattern not capturing points further from the robot (fixing this should also fix the first point)
- inaccurate calibration
- arm rotation not being captured by the current calibration process