MGN12H Linear Guide and Block

Drastically improved the quality of my prints. I was careful not to disassemble or run past the end stops. Cleaned out with WD40 first and then generous mineral oil for lubrication. Seems to roll fine. Machining quality is not the best but way better quality than I would have expected for the price. Holes and tolerances were dimensionally accurate throughout.

Ordered 3 of these, and two came to me loose enough to slide under their own weight (product page specifically calls this out). One of those two also bound up near the end. Both of these also had mounting holes that were clearly not drilled with any sort of precision. At least 1mm variance in hole locations. Sent those back and received two that were comparable to the one I didn't send back. Good tolerance, holes that line up (seriously how is it possible to get that wrong? I have no idea), and no binding. They are still rails that cost 1/5 of what proper hiwins cost, so they feel a little scratchy, but for hobbyist 3d printing, these are more than fine.

Be careful the are not real HIWIN bearing already lost 2 bearings ball on one of them .