The single most important rule when building a 3D printer, one I seemed to have neglected once I got to the final stages. I also managed to NOT calibrate the extruder. at. all.
1st print ran the nozzle through the kapton tape, scratching the aluminium bed.
2nd print started off well, but the bed was not level so the nozzle ran into the print on the higher layers and blocked it (have subsequently dropped the nozzle down the basin by accident in an effort to clean it)
I’ve managed to pick up some stock of nozzles (I hope they fit) and got a digital caliper to help me level the bed and calibrate the extruder properly.