I recently upgraded my Wanhao i3 Plus Mk2 from the stock firmware to the ADVi3++ 4.0.5. At first everything worked perfectly except for some stringing issues and overhang-curling*, but then I had a nozzle-leak and the PLA melted the whole heaterblock into one brick…
After I cleaned everything and reinstalled the parts, suddenly my Printer had a heatdrop the moment when the partcoolingfan kicked in (at layer 2) from 210°C to ~186°C and didn’t recover it’s target temperature before the thermal protection got activated.
My first guess was that I broke the thermistor, so I bought a new screw-in thermistor (I changed the line in the header Configuration.h from 1 to 11). The problem still occured right at the begin of the second layer so I thought the heater-cartridge was damaged. I decided to swap the whole setup to a 6mm 50w cartridge instead of buying a 6.3mm 40w stock one.
After the new heater-block arrived and I put everything together. The first print worked but I still could watch a temperaturedrop from 210°C to ~190°C but it recovered fast enough to not trigger the thermal protection. This time I had forgotten to finetune the PID-Settings, so I did the automatic PID-tuning after the first print, because of the new hardware-setup.
Then on my next prints I got the same result as before: First layer prints good, at the second layer when the partcoolingfan turns on, temperature drops under 190°C and when it starts to recover, the thermal protection stops the printer at ~206°C.
I don’t know what to do next? Maybe I am not seeing the obvious solution? I don’t even know if it is a hardware- or a software-problem, because I think my last firmware didn’t have activated the thermal runaway-protection which could therefore not have been activated in case of a heat-drop.
Please help me!
*P.S.: I got a Diii-part-cooling-fanshroud with a radial fan which I lowered with some washers to fix the overnang-curling problem with overhangs not being cooled fast enough and therefore curling upwards which resulted in the extruder crashing into the part and ripping it off the printbed. Maybe this setup is the problem, but shouldn’t there be a software solution to prevent the quick heat-drop?