Situation:
I have a specific color filament loaded in slot 1 of the AMS. The other slots are occupied with different filaments. The filament in slot 1 is about to run out.
What I want to do:
I want to load the same type of filament into slot 2while the printer is running , so that it is ready to be used automatically when slot 1 is empty. This would save time and avoid having to monitor the printer constantly.
Problem / Question
All I’ve found is that the AMS “locks” the slots while printing, preventing any changes. I understand why, but this seems inefficient.
Is there any workaround to pre-load a replacement filament in the AMS during an active print?
Or is this something that could be considered for future development?
As far as I know, once you start the print using the AMS, you cannot change filament types or colors for your current print, and I don’t think there should be a workaround for that, it would just induce issues.
I think your best bet is to just monitor the handy app, and once the filament runs out, replace with a new spool of the same.
If you put another spool of the same filament in a second bay of the AMS then it will automatically switch to it providing it was there ands detected when you start the print. This is assuming it’s Bambu filament so it knows what is loaded. You get a little icon with auto refill on the print screen in Studio, and if you click on it it will show you which slots will auto refill.
For non Bambu filament I think it will still work as long as you manually set both slots to be the same filament - but I’ve not actually tried that.
If you don’t do it in advance you have to load more into the same slot when it runs out and bleats at you.
Usefully if you run out of your last spool of a colour you can feed in a different one because it doesn’t run the identification when paused.
If I can’t wait, I normally just cut the partial spool so it detects a filament runout. Then I replace the partial with a full spool and let the print continue.
Just to clarify my main point, because I think I am after a different way of working.
What I want is simply this:
Add an identical backup spool to an empty AMS slot while the printer is running, so it’s ready for automatic switch-over when the active spool runs out.
I understand the current way of work:
Right now the AMS locks all slots during printing, which means the moment of spool depletion becomes attended work.
For long prints or overnight jobs, this defeats the whole idea of “unattended printing”.
But technically it can be done differently:
In other production systems this is solved — e.g. 2D production printers allow you to refill paper trays while printing, and they auto-switch when a tray empties. No interruption, no waiting, no babysitting.
That’s the workflow I’m aiming for.
So my question is simply:
Is there any existing method, even unofficial, to let the AMS detect a backup spool during a running print?
And if not, could this be considered for future development?
From a productivity standpoint it would be a big improvement.
Thanks again for the help!
Did a little research myself and I found a random comment that said that if you feed the filament far enough, the AMS will pick up that filament is installed. Basically feed it further than you’d normal need to. So I just tested it myself and it indeed recognizes the filament and it used it as a filament backup successfully. The only caveat to that is that you can’t make changes to the filament settings on the printer or in the slicer even though it’s recognized as being installed. So this will only really work if the slot you place the backup filament needs to have previously been the same type as you are currently printing with.
To help clarify, I started a test benchy print using black PETG in slot 1 on the AMS. Got the print going and then attempted to place a new roll of black PETG into slot 2. It didn’t immedietly pick up the filament and try to feed it like the AMS nromally would. I kept on feeding it into the AMS until the LED turned on the feeder. At that point, the filament shows up in the AMS. At this point I tried to change the filament type on the printer and in Bambu Studio, but it would not let me. I didn’t really need to change anything since slot 2 was previously black PETG, so it was already the right settings; I just wanted to see if I could. I then cut he filament in slot 1 so it would “runout”. Once it detected the runout, it properly switched over to the black PETG in slot 2 and continued the print.
So what you want is partially possible, but not 100% since we can’t actually change the settings in the slicer or the printer once the print has started.
This is something that really needs to be worked on in a Firmware update, giving you the option to pause print and re map AMS, I regularly run 4 day long prints and my only real fail safe is stacking AMS units, Because once I have couple open slots I can’t do anything but work the current active role to refill.
Agree. Just found out that I can’t drop in another spool of filament in the AMS while printing and have it recognized. It’s a problem for us hobbyists that don’t have or need AMS units to stack.
To read a Bambu RFID tag, the machine has to spool off some amount of filament to see the tag. It may even take enough off to be able to calculate the weight of the filament on the spool. To do this, it has to send filament down the PTFE tube. If the AMS is already in use, there is no place for the filament to go so it can’t read the RFID tag. By the original post, all 4 slots were full. You would still have to manually pull the spool in slot 2 to be able to change the filament. So, if you are going to have to do that anyway, change the spool before you start the print. Paper printers don’t have a continuous feed any more so they are not really applicable here.
Add an identical backup spool to an empty AMS slot while the printer is running, so it’s ready for automatic switch-over when the active spool runs out.