600mm MGN12 Linear Rail Guide and Black MGN12H Carriage Block with Anti-Fall Strips for 3D Printer and CNC Machine

Solid rails, good bearings, smooth. I turned a couple of 3D printers into linear rail machines and these were the solution.

I will start by saying that I am very impressed with these bearings and rails. And for the price, they are excellent.Like the pictures show, these are 12mm MGN rails and the included bearing blocks have black ends.In the past, I had purchased different brands with the red and green ends. Those always required cleaning and lubing to make them work well. But these, from ReliaBot work well right out of the box.In the future, if I need more MGN12 bearings for other projects, I would definitely order more of these from ReliaBot.

Unlike the last set I ordered, there aren't any missing ball bearings. Sure, that's a low bar, but they also took the time to include spares - shows that they care about getting you what you need. Not quite as silky smooth as a genuine Hiwin, but more than good enough for a 3d printer. Two of these are currently supporting the bed for my CR-10S.

So I didn't put it on an inspection table didn't feel the need to however I did clean and re-grease the carriage I'm a firm believer that you can skip this step for a short time especially on a 3d printer the loads aren't even close to what they're rated for however I did it cus it gives me the warm fuzzies haven't had a problem yet and it seems solid even after about 100 hours or so of printing

Don't pop off the rubber endstoper the barrings will come off spilling little barrings all over.. They are not really attacked very well so be careful put a zip tie through a hole when you get it or something so you don't go chasing after barrings. If you do you can slide the barrings back in between the wire gently wobble the barring around then add more until they're full put it on.. if any fall out o well.. just stack that sliding doohickey in the rail tight and deep. screw it in to it's new home and give it a good tap.. see if it slides.. if it didn't you can kiss your finding barrings on the floor goodbye! They work great smooth and nice!!! But I feel like they're a bit over priced for the knock offs in 600mm for the size. oh well..

I ordered 3 of the 600mm rails for an upcoming project. The quality seems pretty good. One of the 3 that I got doesn't feel very smooth, like there is a drag in places. I am hoping it is just some small particles in the channel or bearings. I will need to remove them and inspect it closer, but the rails all look straight and sturdy. I will update my review when I find the issue.UPDATE 04/04/22: After inspecting the block closer, I did not see any obstruction. One side of the bearing assembly just wasn't smooth. It wasn't the bearings, it seemed to be one of the plastic end pieces had a flaw in the channel. I contacted ReliaBot and they sent a replacement. Excellent Customer Service!!!

Rails slide smoothly. No discernable play in them as well. Only problem is one of the carriages is missing ball bearings ~6 or 7 of them. I fortuantely ordered 2 rails and they both came with spares so I should be able to fix the problem.

Only a handful of vendors offer an all stainless steel rail plus block. This vendor had it in the lengths I needed and I purchased two sets. I've ordered other rails and it was horrible. When these arrived, I was pleasantly surprised to find the block glided very smoothly on the rail. I oiled it and it's been in service for about two weeks with no issues. These sets also came with extra bearings. I did notice a slight dark brownish discoloration on one of the block. Although it didn't affect the function of the rail, the rail ends were not squarely cut.