Was just the driver for me, dc42 told me to remove plastic molex near by becuase they will get crispy.
150c hot air will get them off slowly with pliers.
Find my post there is info that will help you there.
@hamiltonprops From re- reading your OP, you say that the temperature drops 20 degrees within a second or two. That would indicate it's not a "real" drop in temperature but rather a drop in the indicated (measured) temperature - unless your hot end has an insanely low thermal mass. So, yes I go for some sort of cross talk or electrical "noise". Are you sure you haven't got a bad crimp on the thermistor wiring somewhere?
Hi everyone, I solved this buying a silicon cover for the heat block (as Phaedrux mentioned) you can get some pretty cheap on Ebay, I also realised that you don't need to have a E3D hotend, they are not available for every hotend, but you can found for the most common. With this the temperature only goes down 5 degrees and in a few seconds it's in the desired temperature again.
The nature of the temperature graph suggests to me that there is a problem in the thermistor wiring.
The fault came up again today, so I went trough the usual procedure of resetting and turning the heater on again. Only this time I noticed bumping my printer actually causes a 10-20°C temperature fluctuation, producing a temperature graph I not comfortable posting here. 🙂 Sadly I was not able to make it fluctuate just by fiddling and wiggling with the thermistor wire/connection.
as i mentioned before i orered new sensors to replace the e3d cartridge type ones. A german shop i found stocks both PT100 and Type K sensors in cartridge configuration:
Type K click
the only drawback is that the Type K variant is only available as 4 mm diameter. They are not even expensive however and (to my experience) of much higher build quality than the e3d types. The lead length is variable and they feature ferrule ends matching the Duet Daughterboards perfectly (as opposed to the e3d types which have to be fitted). Last but not least they are specifically rated for 400 °C and 550 °C respectively. I am running the PT100 type right now and am finally able to print again.