I am running Groundcontrol on Ubuntu Mate 18.04 .
I did check the Wiki how-to-get-calibrated and all goes well up to step 10,
From step 11 it goes wrong .
in Step 11a point 3. , it says : The left sprocket will turn counter-clockwise and retract the chain to a determined length (suitable for connecting to the sled). Well, mine ran clockwise instead of counter-clockwise ???
the right sprocket ran clockwise as well, but is OK because it is supposed to 
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