you don’t need to know the exact weight of the spool to know how much is left. It can estimate how full a spool is even if it’s not a bambu spool, so the RFIDs are irrelevant too.
The AMS knows how much filament has been pulled through the gears and it knows how much it’s rotated the rollers. When the spool is full you need to rotate less per CM of filament. When the spool is empty it needs to rotate more. It’s constantly adjusting how much it spins the rollers to get the right amount of filament off of the spool. That’s how it can make a guess at the amount remaining.
There are only 4 dimensions needed to do the calculation of how much is remaining (the length, not grams).
- filament diameter
- spool’s outer diameter
- spool’s inner diameter
- spool’s width.
If you keep a memory of filament pulled relative to roller rotations over time you can actually do away with the width dimension.