All M180 is pre-calibrated in factory, users don't have to calibrate dual-extrusion in most cases. 

If machine setting is erased(eeprom full reset), calibration value will be reset. 

The intergrated dual-extrusion calibration pattern can only adjust +-0.7mm at one time. If needed to adjust left for 2.0mm, please repeat to input value 1 for 3 times. 

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