My Mini (type1) used to gauge the Z-axis height during the pre-printing stage (just after nozzle cleaning) by descending to each of the metal discs at the corners of the buildplate in turn. The nozzle would touch a disc, back off about 1 cm, then come down more slowly and just “kiss” the disc, and retract – then onto the next corner etc. Now, on the “second” approach instead of “kissing” the disc it remains touching it for about 1 second and meanwhile you can hear the z-axis motor still trying to turn. (It gives 3 or 4 little “tock-tock-tock” sounds). Then the nozzle backs off and does exactly the same with the other corner discs.
Has the latest software update changed the way that leveling is done, or do I need to clean the nozzle tip to ensure better electrical contact with the discs? The Z-axis offset and Estep value are correct for my machine (I always check them when up-dating the firmware). I am using Cura:3.6.20, Firmware: 220.127.116.11. I am using ABS. The nozzle wiper is new.
Strangley enough, the parts turn out as good as ever in spite of this leveling business.
Update: I cleaned the nozzle with acetone so it would make good contact with the four corner discs. I checked that there was good contact with a multimeter set to ohms. However, this did NOT cure the problem. I’m guessing there is a poor connection either from the corner discs or from the printing head to the circuit board. A broken wire? A corroded multipoint plug? I need to investigate. Anyone else met this problem.