I designed this A1 external spool holder upgrade so I could actually use the external spool holder that came with my A1 printer. Before when printing TPU, the filament would be very hard for the printer to pull down causing under extrusion. Now it's very smooth, works perfectly and I can put two spools instead of just one.

The hardware required for this build is:

(4) - 608 ZZ bearings which are very common. I got mine from my wife's old roller blades.

(2) - Screws, 50mm long x 3mm shaft and 4.8mm outer thread diameter, but most importantly a tapered head larger than 8mm so it aligns and holds the bearing in place.

Installation:

-Remove the 6 screws of the A1 spool holder with the included hex tool that came with your Bambu Lab A1 to insert the Main Center piece. It can be somewhat difficult to unsnap the piece and the plastic retaining tabs might break off, however there are 6 screws holding it together so the tabs are not necessary.

-Place the Main Center piece in place with the slot in the middle aligned so the upper piece can slot into it. Once it is in place, put the 6 screws back in.

-Take one 50mm screw, place a bearing on the screw and make sure the head of the screw will not pull through the bearing.

-Next place the bushing on the screw and then another bearing and lastly the washer with the flat side facing away from the bearings.

-Screw all of this into the Main Center piece and then slide on the Spool Main part and that's it.

-Repeat the steps for the other side if you want it to hold two spools.