This spool adapter is specially designed for the A1 & A1 mini with the AMS lite system. It's meant for non-Bambu Lab branded filaments with too large internal diameter (ID) spools. When loading those filament spools as-is onto the Rotary Spool Holder of AMS lite, the 'auto rotate' function of the AMS won't work properly. The auto rotation of the Rotary Spool Holder ensures the filament rolls on the spool are tightened and maintains tension. It also helps to retract filaments to the right position during auto filament changes while printing.

Rotary Spool Holder:

I modeled this Ultimate Spool Adapter to solve many problems I've experienced with other adapter models in the market. If you've encountered the issues listed below, you won't be disappointed with this design.

Problems with other adaptors:

1. Adapter outer diameter (OD) is too small to generate friction between the Rotary Spool Holder and the ID of the filament spool, bypassing one of the key functions of the AMS lite.

2. Adapter is too stiff, making it difficult to install into the filament spool. Some adapters' hooks get damaged during installation or removal.

   

3. Adapters are hard to align with the 3 'arms' of AMS Rotary Spool Holder, causing one of the arms fall into a slot on adapters, preventing the spool from sitting perpendicularly to the rotate shaft of the Holder.

   

4. Adapters are hard to be pushed onto the Rotary Spool Holders, especially past the grey rubber pads on the arms. Those pads are meant to increase friction to maintain good bonding between the filament spools and AMS for auto rotation. Poor adapter edge quality can prematurely wear out these pads during frequent filament changes.
5. Adapter gets pushed out of the spool when trying to load it onto the AMS, or when removing a spool, the adapter doesn't come off with the spool but gets stuck halfway on the AMS.

This Ultimate Spool Adaptor solves all the above problems:

1. It's flexible. I've printed with PLA, PLA Matte, PLA+, PLA Silk, PETG.  All are very flex as shown in the photos.
2. It's easy to install into and remove from a filament spool at will.
3. It slips onto the AMS Rotary Spool Holder smoothly with groove and gradual chamfer design.
4. Large outer and inner rims ensure the adapter stays in place until you remove it. The spool can rotate perpendicularly to the holder's axis to prevent unintended wear of AMS.

Hope you like this design! Feel free to drop me comments if more improvements can be added to this design. Thank you.

Update 2024-11-05:

Thank you for TheBags's inspired comment about using this adaptor on modified SUNLU spool. I've added a new print profile by adjusting the adaptor a bit longer. This is for user who converts their SUNLU spools so that Bambu Lab filament refills can fit into the wider converted spools. Users do not need to adjust the length in the slicer on their own. 

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