LUNEE MGN12H Linear Guide Rail 12mm with 2pcs MGN12H Carriage Block for 3D Printer and CNC Machine、Laser Engraver (400MM, Silver, 1)

so one of the two sliders on my 400MM unit has something wrong with it. It has an intermittent catch like their is either a bad ball bearing or there is some kind of debris in the internal track. When I slide the bad skate along the track it hangs up, but not every time. Other than that these slide and skates all seem to be of nice quality. there is some plastic but not a lot and nothing that I would think would impact performance unless you are using it in a high temp location. The set shipped to me relatively quickly and for the most part everything was in good working order apart from the one issue I mentioned. Other than that this seems like it will work fine for my project once I get that skate figured out.

I'm planning to (one of these days) convert one of my 3D printers to a linear rail system. I got this 350 mm linear guide rail in silver from Lunyee.It arrived well packaged and covered in plastic. It matches the specification. It slides smoothly but with a touch more friction than I was expecting. I will look to get some lubricant for it when I start installing it.There are two carts on the rail. I expect to only need one, but will keep the other as a spare.I think this should work perfectly for what I'm going to do.