… in theory the filament should slip off the spool, filament sensor detects its end, and a new spool is loaded automatically or the user is notified.
… practically filament does not slip off the spool always (because if it is too loose the AMS cannot retract and rewind the spool) and so the print will stop, and the user must do something.
Wouldn’t it be possible to detect if too much force is needed to pull the filament?
Then it could just rewind it to the spool, block this spool and load another one from the AMS. In the current state it is pretty useless for massive prints where spools run out during the print.
What I started doing with great success is respool each spool of filament. I drill a 2mm hole at an angle in the side of th spool, tape about 1/2 inch of the filament to the side of the spool. After the filament is respooled, I cut the filament flush with the side of the spool. My H2D will use the spool completely and then start the second spool of the exact same filament, seemlessly. Just like magic.
I discovered this trick by noticing how Prusa PC spools terminate the filament.
Or maybe there could just be an option for unattended jobs to not fully empty spools - i.e. Change over a convenient point, ideally a colour or layer change, when the spool if nearly empty (which for BL spools could be detected by RFID rotation rate).
Almost empty spools could then be used up on less important jobs - ideally where someone is in attendance and could therefore manage any ‘filament release from spool’ issues.
Would also save the waste that happens when you do a colour change just after the filament has ended - where there is still a lot in the tubes which then has to be purged out because the AMS can no longer pull it back.
