Thank you! Thank you! Tried everything to get my printed spools to rotate without slipping. Scored the axles, added tape etc but nothing worked consistently. Printed your sleeves and I'm up and running again.

This resolved the issue I has having with the spools not rotating. This dryer almost got put in the closet but now it is KING again. Thank you!

these did the trick!

What do you think of adding alternative designs of sleeves? As when rotating, spools sometimes move around a bit, and sometimes get cought in recess between two smaller sleeves or start rubbing against side, and i notice eg. one of spools stopping spinning. Hence i'm thinking of maybe thinner sleeves (to not get far from how stock roller acts with eccentric o-ring of motor), but symetrical full length +small (to not need supports) slightly rounded up (to limit spool side movement) lip/detent +plus thinner & narrow (0.2-0.5mm?) extra lip behind spool detent one, with diameter not larger then bearing's inner ring, so to not care if "lip" will friction against bearing or plastic bearing holder. This way imho one can just move sleeves to very side till bearings, and due limiting lip spool will never move too far to sides. Alternatively - make whole roller anew with smaller diameter then stock one, from some higher temp filament (i.e. not PLA, PETG/ABS/ASA/PC, to have glass transition temp > max 70C of dryer), and with according smaller diameter sleeves (for total diameter of new roller+sleeve to be of same diameter as stock roller). Also, as this is TPU print .. how about adding to set small plugs to 6 bottom holes at bottom of dryer's lid for alternative filament pass out paths. There are stock caps for top, but those down slightly bug me. Moisture inside of switched off dryer imho gets up slightly too quickly.

The sleeves actually made the problem worse. While rotating, the spools (Bambulab spools in my case) tend to move a bit and one side gets caught in the space between the sleeves, whilst the other side remains on the bigger sleeve. This actually causes the spool to stop spinning. There was no issue in printing the sleeves, installation instructions were clear, but for me at least it made the problem worse.