I have just turned on my factory assembled bigbox pro. I followed the instructions for first print from the manual but the filament feed seems to judder and will not give me the 100mm extrusion it says it has extruded. I don't understand how the filament tensioner works so am producing failed prints no more that 5mm high. I have changed the filament thickness and also the Esteps. they are now at 1107 for a 1.75mm filament and still only yielding 70mm not 100mm of the calibration test So I guess that it is the tension.. does anyone have any ideas? Maybe a welcome pack was left out of my box or a link to a manual for prebuilt printers, I would have hoped that a power lead could have been included and that the filament could have been labelled. Also the inclusion in the box a sheet of paper spelling out what to check and how to set up and links could have just made it a better initial experience. Any help gratefully received.