as I am getting increasingly frustrated with my H2D it just threw another issue at me. As I was printing a PLA print, the filament in the AMS ran out. I was aware this would eventually happen and waited for the printer to alert me so I could add the new spool when it was time. When the alert didn’t come for a surprisingly long time I went to check on the printer and found that it had autonomously swapped to the left nozzle, which had PETG loaded. Needless to say, the print has failed.
Can anybody tell me how I can disable the automatic switching to the second hotend? I didn’t even know this was the default behavior and I hate it! The fact that it just switches to another material without asking or anything is ridiculous and I would really like for it to just pause and alert me instead of jeopardizing the entire print.
Do you have auto refill turned on? It would do this if you had this setting activated and you had the materials improperly labeled in the Filament menu of the printer.
So far, I have never seen that the printer switched nozzle. I believe that isn’t even possible since the gcode needs to be altered for this.
I have no clue how this happened
When youo filament runs out, the printer will indeed continue until the runout sensor in the tool head is triggered.
If you load a new spool in the same slot when the filament has exited the AMS and passed the last splitter in the PTFE tube, it will immediately load the filament and pushes it against the backend of the old filament. Basically giving you an uninterrupted filament flow.
The reason you have to wait until the laat splitter is passed, is because otherwise the filament gets stuck because it passes the end of the first spool and gets stuck.
I’ve given it a try and disabled the auto-refill. Now the printer doesn’t even interrupt the print, even though it clearly detects that the filament has run out, as is apparent by the icons on the screen.
So to summarize:
Auto-refill on → Printer switches to wrong filament upon material runout
Auto-refill off → Printer ignores filament runout and pretends nothing happened
From a machine supposedly this sophisticated I really expected much more.
Thank you for your reply. The g-code of the print is not related to the runout detection besides there likely being a flag in the start g-code that may toggle the behavior on and off. And since I have observed it happen live we can rule out that it is not possible. Your suggestion also is not a solution as it would require me to permanently monitor the printer. I don’t think you would want to do that either.
I agree that this requires babysitting the printer and is not the optimal solution.
However, having 2 spools of the same filament in the AMS 2 has given me no issues either. When one spool runs out, the other took over. Only disadvantage here is that there is a slight artifact at the location in the print between the filament change. It purges properly, but it seems that there is a bit too much retraction before it starts again, resulting in a slight gap. As long as it’s not on the periphery of the part it’s not an issue. But I had it once before n a visual area.
The babysitting method, doesn’t have that.
But I never seen it switch to the other nozzle. Sounds like a glitch. You might want to extract some logs of that event if you can reproduce that.
The issue persists and today an expensive TPU print of mine got ruined! The TPU ran out and the printer swapped, unsolicitedly, to the left nozzle upon runout and continued printing with PLA. This issue is insanely frustrating by now because it is costing me a lot of money, time and nerves and there is nothing I can do about it!