Check pictures for instructions.

Now works on ALL A1 printers, the older with threaded axle and the newer with moulded axle using the new axle end plug as well as A1 mini using the new adapter sleeve. Modification to original holder required (not threaded version) to allow for this best performing solution with spacers for lowest possible friction. Please no low ratings because modification is necessary. Bambu chose moulded axles and I chose best performance. So basically it's all Bambu's fault and not mine xD New holder is 10 resp. 4 Euro in store anyway. I bought these extra just for development, for your benefit. Thank you for your understanding! =)

OBS! Freshly cleaned buildplate. Use soap + rough side of dish sponge, not isopropyl alcohol, to avoid bearing rollers detaching. Textured PEI Plate recommended.

Low friction spool holder with printed internal bearing to avoid extruder motor stress and varying resistance and so that the spool rolls instead of drags. Optimized for low vibration and low friction. Tolerances are as close as possible with less than 0.01mm from not rolling freely in order to minimize vibrations. For the same reason I choose to make the diameters (and roller length) as big as possible at the cost of spool clearance. So I also made the PTFE-tube Swivel Support (included) for 2mm extra spool clearance and filing guide included for the 2025+ model year version. Some spools like Polymaker fit in height without it but for ex. Bambu spools need it as seen in picture. It can take spools of width 67.4mm / 2.65 inches which includes my widest. Surface finish is not perfect due to random seam alignment and scarf joint seam not performing as well on these radiuses but I optimized the values for the seam as best as I could find and it's better than the alternatives for the overall most smooth and uniform rolling surfaces.

• Use End Cap Knob (or tape alt. remove end cap, see pictures) to easier screw in and out the axle. Mount with removable glue like for ex. hot glue. Two small dots is enough. 
• End Cap Knob looks a little better with Classic Wall Generator. Makes middle outside perimeter a little smoother. Difference can be seen in slicer. Rest of parts, i.e. all functional parts have tolerances optimized using Arachne Wall Generator only, along with rest of settings in in print profile (listed in description).

• The PTFE-tube Swivel Support unscrews from the right side, inside swivel hole using 2mm hex.

   

Print spool and rollers in softer filaments to further minimize vibrations. I recommend PCTG for spool and a quite hard TPU like 95A with 100% infill for rollers. For ex PETG and PLA Silk or Matte are also softer than PLA. Use print profile #5 for TPU and PETG rollers. It uses print-by-object for better quality and tolerances. I previously used my favorite filament PCTG for both spool and rollers but not for the spacer which became a little looser around rollers. 100% infill for rollers aslo helps some amount to counteract vibrations with added inertia and I'm pretty sure the tolerances got a tiny bit tighter yet, I'd guess due to less shrinkage. I print 15% gyroid infill at 100% speed with such tiny vibrations I thought there were none at all until I double-checked with ear next to it, while printing from drybox and no filament spool on holder. Some rarer frequencies still produce vibrations but none louder than printer itself. That is using rollers and spool in 100% infilled PCTG and spacer in PLA. Now with rollers in TPU 95A it's even better.

Hope you like it! 

Check out my other A1 series mods.