Hi all, I ran into a strange problem with my H2D on the latest firmware. Though the printer prints well, it seems that when loading/unloading filament, the printer uses the minimum temperature of the filament previously loaded into the printer as opposed to the normal printing temperature, and on some filaments (the problematic filament for me is the support for PLA/PETG), the low temperature creates too much resistance for the extruder to melt the filament already in the nozzle. In this case the extruder makes clicking sounds and nothing is extruded. In one instance this happened during the preparation stage of a long print, and I was shown the dreaded ‘extruder overloaded’ error.
For example, if my last filament is Support for PLA/PETG, with a minimum temperature of 190, I can try loading another filament, and the printer will then only heat up the nozzle to 190 degrees before trying to extrude and purge. A lot of times, 190 degrees is not hot enough to allow for Support for PLA/PETG to extrude, so the extruder clicks and the loading process fails.
I initially suspected maybe the left nozzle (which this problem occured on initally) slightly colder than the thermistor reading, but after cross checking the filament with the right nozzle (and an A1 mini for good measure), I found that none of them were able to reliably extrude Support for PLA/PETG reliably at the minimum 190 degree temperature. Raising the temperature by as little as 5 degrees sometimes allows it to extrude.
The loading & purging routine on the A1 in my experience will always raise the nozzle temperature to 250 degrees even for relatively low temperatures such as PLA or Support for PLA/PETG, so there was never a problem like this.
Has anyone else experienced this issue? In my opinion Bambu Lab should probably increase the filament loading/unloading/purging temperature from the minimum temperature to the normal printing temperature, or even the maximum temperature (like the A1), which would be more reliable.
I’ve attached some photos to show the printer attempting to load PETG HF (230 degrees minimum temperature) while only heating thr nozzle to 190 degrees due to the previous filament being Support for PLA/PETG.
