Enlightx - I had the same problem you described. After reviewing the code that determines the location to do the three probes based on these values in configuration.h: // these are the positions on the bed to do the probing #define LEFT_PROBE_BED_POSITION 30 #define RIGHT_PROBE_BED_POSITION 150 #define BACK_PROBE_BED_POSITION 260 #define FRONT_PROBE_BED_POSITION 30 // these areby s3tech - General Mendel Topics