Hello, I just got my X1C combo with and extra AMS, I see a lot of people having issues with smaller spools or light spools and feeding issues. Maybe a possible revision or add on for future AMS is to have a spring loaded roller for each sections so 4 rollers placed on top of the ams or at the back with an arm so to speak and that way there is a spring tension on the back upper portion of the spool so it doesn’t kick out. This would also help if it was adjustable so smaller spools will work. As someone who does a lot of reviews for companies I get a lot of these 250g spools. I wish I had the free time to sit down and model up a mod like this to show but I can’t.
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wrt “light spools” you can use something like Printables filled with desicant (or with screws if you need more mass) to make spool heavier
as for the “small spools” and other improvements for the AMS there is Printables that replaces the inside of your AMS allowing for more spool compatibility than default AMS (you can fit in larger spools, smaller spools…)
It’s not the weight of the spool that is causing it to kick out, it’s the weird logic of the AMS.
I too thought that the spools kicking out and binding with the top case was because there wasn’t enough weight holding them down when the AMS feeds the filament in but that is not at all what is happening.
If you open then lid when the spool is binding you will realize that the AMS is locking the rollers and preventing the spool from spinning instead of letting it spin freely when the feeder mechanism is pulling on the filament. If you try to spin the spool it won’t move freely because for whatever reason the AMS is coupling the rollers to the motor but not spinning the motor.
If you turn the spool by hand and overpower the roller motor, it will decouple the rollers from the motor and spin freely again allowing the filament to feed in correctly.
This could be a bug or Bambu overlooked something in the firmware but there is definitely an issue with the order of operation between the mechanisms in the AMS. This issue is self-inflicted.
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I noticed this too. I’m jot sure if it is because the spool is t heavy enough to apply the correct friction to get the rollers going.
What I mean is, I noticed that if I manually move the spool the AMS rollers are locked tight, but when I apply downward pressure and roll the spool in the correct direction it unlocks and begins working as it should.
So, what I think by weight, is that, the spool isn’t heavy enough to prevent lifting or being pulled without disengaging the roller lock.
Because if you manually do this, the spool will run until empty without issues. I’ve put in rolls with like 150g left in the, manually rolled them, and boom prints fine.
Just my two cents for whatever it’s worth.
It only happens during the initial feed operation, and only sometimes. And if you assist the spool by spinning it by hand it still takes a considerable amount of force to get those rollers to spin, the spool would have to weigh 10kg to apply that much force by itself.
I’ve been closely watching what actually happens in the AMS when filament is loaded and some things just don’t make any sense.
Under normal operation:
- As soon as the first stage feeder starts pulling on the filament, the first stage motor momentarily couples with the roller to give the spool an initial push to get it to start rolling until the filament reaches the internal hub unit.
- Once the internal hub unit picks up the filament, the first stage motor then decouples from the roller and allows the spool to spin freely on the roller while the internal hub takes the filament the rest of the way to the print head.
What is happens when the spool gets jammed against the lid of the AMS is the roller never decouples from the first stage motor after the filament has reached the internal hub, resulting in the roller preventing the spool from spinning freely.
Any update on this?
I am experiencing this nearly every print now on a 1 week old unit. I find if I rotate the spool backwards it decouples the rollers and spins freely, then I can try to resume.
@BambuLab please issue an update to fix this, it is causing multiple failed prints and headaches on a system that works so well otherwise.
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I just received a P1S and I am having the same issues with my AMS on spool 3 (if that matters). It only started occurring when the spool got to around 400 grams. It primarily jams up when retracting between filament changes. I have to decouple the bowden tube from he back for the printer and manually pull it from the printer. After that that AMS is able to retract but creates a birds nest as it is feeding it back onto the spool.
I am hitting this problem now as well
Latest firmware (upgraded this morning) and software.
I have printed smaller rolls before without issues using adapters printer out, but now I am trying to print with some transparent petg from IEMAI and the weird situations with rollers stopping put pulling still happens occurs on almost every filament change.
Is this caused by some filament setting since I have not seen it with any of the smaller pla rolls I have used before?