Home your carriages. Mark the bottom of one on the extrusion. In Pronterface or another host program, tell the printer to go down (Z) 100mm. Measure the distance that the carriage actually traveled. Adjust your steps/mm until you get 100mm.
I really could not tell from the video, but it looked like your extruder was over-extruding. If you have not done it yet, mark the filament and repeat the above steps with the extruder.....
I really could not tell from the video, but it looked like your extruder was over-extruding. If you have not done it yet, mark the filament and repeat the above steps with the extruder.....