Using the AMS 2 Pro on H2D:
Print something in ABS with 270°C, then switch back to PLA with 220°
The expected behaviour is the following:
The nozzle heats to a temperature that melts the old filament, filament is purged, temp is set to new temp and then a little more purge or something like that, then PLA is good to go. If not, the user should be given the opportunity to set heat and movements one by one while the print process is paused.
The actual behaviour is the following:
The nozzle heats to the PLA temp of 220°, tries to purge, but ABS is not soft enoguh, motor overworks, Filament driver in the AMS and tool head destroys the PLA, so it can not be advance later. Display shows an error message. User sets temp to 270°C manually. But filament can’t be extruded nor retracted due to the motor destroying it. User must remove PTFE tube on the tool head and help it by hand. Now, for absolute no sane reasons the AMS starts to forward the filament non-stop and thus pushes meters of filament into the print area. The user can not stop the process because the display shows no process. The user must switch off the power to the printer. The user power on the printer again, he wants to retract the mess, but can not do so manually because the AMS hold on to the filament tightly, so the user must select the “unload” option in the AMS. The AMS does not just retract the filament but start to move the print head around eradically and hurts the user who has its hand in the printer because he want to untangle and guide the filament back (there was no warning that the print head will move, like there is when you select “read nozzle information”). The print head gets tangled up in filament even more, then it tries to pull it out. Again no way to stop it. The user must again turn off the machine, then cut all filemnt in the print area and throw it away. Then start over to try to heat up to 270°C and purge the remaining ABS.