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[flynn]

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[jeffnic]

This may not help, but my son and I had a similar problem on our first calibration. We found that the carriages weren't hitting the limit switches at the top, I guess this was causing it not to 'know' how far to travel down.

We figured it out by turning off the printer and manually moving each carriage up to the top and listening for the click it makes when it hits the switch. Two of ours weren't clicking - we adjusted the screws that actuate the switches - calibration ran ok after that. Good luck!