I noticed that when I used Polymaker’s cardboard adapter that the bobbin jammed against the cover. The bobbin adapters diameter was 201.8mm. Bambu says the AMS can handle 202mm bobbins. I have found that it can only handle bobbins up to 201.2mm without hitting the cover. This was true for the 3 AMS units I have. I switched to bigdog7’s adapter but I had to shrink it to 200.8mm outer diameter. Works great!
I had to shrink his model too. My printers calibration is spot on so unless my calipers are both wrong they have changed something. My guess is the AMS roller diameter is larger.
I don’t run cardboard in my AMS units. All you have to do is respool one to a BL spool and see how much dust the cardboard creates. And most of the time the paper spools are crushed or have dings on the rim.
I tried bigdog7’s adapter, but it doesn’t fit an eSun spool without damaging the spool, (eSun spools are 54.3mm not 55. I decided to create my own universal adaptor that can be used with any size spool including mini spools. The diameter is 201mm and works fine in my AMS. Uploaded to Makerworld with step files. (Universal Cardboard Spool Adapter For AMS)
Related question- I just purchased esun filament on amazon. I didn’t realize the inner cardboard lining is smaller than bambu and other filaments so my spool will not fit inside the cardboard ring. I tried looking up other plans, but the ones i’ve found are also too big. I already tore off one side of the cardboard spool so most plans that add onto it won’t work. Any ideas? Thanks! Still new to this.