BQLZR SC8UU Linear Motion Ball Bearing CNC Slide Bushing 34.5mm Length Pack of 4

They work really nicely and the fit is perfect.

Worked for what I needed. I purchased them as replacements for the ones that came with my 3d printer (a Prusa I3 clone). I knew they would probably be similar quality, especially given the price point of the printer and the bearings. Some of the ones that came with my printer had all the ball bearings fall out of the assembly. I don't know if it was the way I inserted the linear shaft, or if they were cheaply made. I was hoping it was just one bad bearing but it happened on a few different ones, and also on one of the ones I purchased here.But the ones I have on my printer now are working fine, one I had the shaft on them, I don't have to worry. They seem to slide ok, a little rough, but again for the price, I don't really have a complaint. I know high precision bearings cost a lot more. These worked for what I needed them for.

Great for their cost. Sure they are cheap and maybe they had a couple of rough motions at first, but that worked out. I wasn't willing to pay McMaster-Carr prices for my slide and I knew that I get what I pay for. I say they are great for the price.

The media could not be loaded. Construction is excellent but the friction to movement was about 25g. For your application that might be no problem. For mine it was a deal breaker.

Bought these to replace a bad bearing on my Anet A8 3d printer. I finally had enough time during covid lockdown to finish putting the printer together after buying it 2 years ago. One bearing was dragging and distorting my prints so I got these as replacements. The reviews were so great I originally thought I would go ahead and replace all my block bearings but these weren't even as smooth as the original bearings after sitting for 2 years. They fit and they work but nothing to write home about.

Excellent! Used these on my MP Select Plus printer, and it the sound difference is night and day. I did not realize how noisy the tray axis was until I quieted it down with these bearings.

thought i would be stiffer in all axis. i already planned on using two per axis should be fine for a printer

Bearings have a lot of loose space between them and the aluminum block. If that wasn't enough, the 4 holes for mounting are not tapped all the way through, the metal is super soft and can't hold a tightened screw, and the holes are not consistently placed. I can handle holes misplaced but consistent, but the dimensions are off substantially(.05 inches average! They are horrible! Don't even try to use more than one per linear rod, as they will bind due to being misaligned, thanks to the horribly inconsistent hole placement.