Aokin 3D Printer POM Wheel Plastic Pulley Linear Bearing for Creality Ender 3, Ender 3 Pro, Ender 3 V2, CR-10, CR-10S Series 3D Printer, 10 Pcs

They turn and keep the belt tight. Thats what they are suppose to do.

Once loaded about half of these bearings actually wanted to cease. Most of them would have randomly clicks and grinds. Very poor quality.

Use these for 3D printer and laser biulds works great

Finally pulley wheels that are round! Too many of the other ones Ive tried have been oblong and absolutely ruined my prints. With these, the first 3 I pulled out of the bag and installed were perfect and my printer is resurrected. I havent tried the rest yet, but the last batch I had from another brand were ALL bad. Do recommend.

Perfect fit. All 10 were in good condition with no defects detected. All I did was add a touch of liquid dry lube and they were very smooth. I will buy again if/when needed.

Great products

This is the third set of rollers Ive ordered from various Amazon sources and so far, these are the best quality Ive received. All ten rollers look and work perfect. No surface defects on the plastic, no loose fitting bearings, no missing spacers. They worked perfect on my Ender 3 bed and X-carriage. They are well packaged and came with an information sheet. Overall, a very good purchase and Id buy them again.

My printers original wheels had developed flat spots from having the eccentric nuts over-tightened, and were seriously messing up layer height consistency and positioning accuracy. These replacements were an exact fit and immediately fixed my problem. I just used 6 for the Z axis and kept 4 as spares.

I should have payed more for bearings, these things cut corners from the low quality grease to the inconsistent build quality to the sheer amount of friction in these even when warmed up. In the future I hope you can get in contact with your supplier and test the quality of a batch before someone else ends up halfway through a 3d printer rebuild only to find the old worn out bearings roll better than these. Sorry but now both our days are ruined.

Came in great shape and was able to swap out a few wheels easily on my Ender 3 V2