I ordered off AliExpress, but they're terrible. Perfectly smooth, but filled with thick grease and they spin only reluctantly, with significant resistance. I followed a couple of sets of instructions from the Internets to clean them out, but nothing really helped. After all, they're sealed bearings...

608bearing dimensions

Anyone been down this road before and have a recommendation? Does a higher ABEC rating mean that bearings will spin more freely, or is that just money down the toilet?

I'm looking for a supply of cheap ball bearings to use in building random projects such as filament spool holders, fidget spinners, and kinetic sculptures.

608RS Bearing

The standard quality rating system for bearings, ABEC, seems to care mostly about dimensional tolerances. Most cheap bearings are unrated. ABEC-3 is el cheapo, ABEC-5 is mainstream, and ABEC-7 is premium. Prices increase steeply as you go up the ABEC scale. But I don't really care about exact dimensions - I'm just going to be stuffing these into thin plastic housings, so it doesn't matter if the dimensions are off by a fraction of a millimeter. I just want them to spin freely.

/r/3DPrinting is a place where makers of all skill levels and walks of life can learn about and discuss 3D printing and development of 3D printed parts and devices.