Review on Usongshine Sliding Engraving Machine with Advanced Bearing Power Transmission by Ryan Bennett

I bought 4 of these (MGN9) to convert my CoreXY 3D printer's Z axis from rods to rails. I had already converted the X and Y axis to rails (different brand) and these rails had to be thoroughly cleaned and re-oiled before use. This is to be expected from the cheaper rails sold here at Revain. But I am very happy to report that not only were all 4 rails packed very well in individual boxes, but all 4 moved smoothly and freely. I am very impressed with them considering my previous experience with other brands of rails. I don't even have to clean and re-oil them - they're ready to go! I will be ordering more of these for another printer I have.