Bambu A1 External Generic Roller Spool Holder

Adds a 608zz roller spool holder to the Bambu Lab A1 external spool holder. I needed a spool holder that uses bearings so I could feed TPU without resistance. I bought my printer in February 2025 and the external spool holder it came with has the molded arm (non-removable), so I can only attach this model to the left side. Please check that your external spool holder has this hollow to insert into before printing this model. The roller uses two 608ZZ bearings and is assembled with one M3 heat-insert nut and one M3 screw (8-10mm length). I only use this when I print with flexible filaments, so I feed the filament directly to the extruder without a PTFE tube. If you want a PTFE tube for the left side, you can use one of the many PTFE holder options on MakerWorld, such as A1 Dual Spool Holder (2025).