ReliaBot 550mm MGN15 Linear Rail Guide with MGN15H Carriage Block - High Precision Linear Motion System for 3D Printers, CNC Machines, Laser Cutters & DIY Projects - Perfect for Smooth Axis Movement in Maker and Industrial Applications

Well packaged and lubricated. Perfect length for my DIY Y axis application.Would recommend this vendor over all others for quality control of this 450mm MGN product.This is the fourth linear rail I have purchased off of Amazon. All of them were on the lower end of the pricing scale and the other three definitely showed that. This rail though, this rail is surprisingly good. Packaging was decent, rail is super straight, block slides easily and does not snag. I will still clean out the block and regrease it to ensure it is properly lubricated but I am very happy with my purchase. My Hypercube Evo is about to be happy as well!Ordered three of the 600mm MGN15 Linear Rail Guides. They all work fine. Good value for the money.Cleaned the cosmolene using WD40, then oiled with a light machine oil. Glides smoothly and no discernible lash. Used these to replace the CR10 V-rollers on the Y-Axis. Very satisfied with the results.Updated my 3D printer to use these linear rails. Came in clean, and smooth.Initially, 2 of them weren't flush or completely linear against the extrusion but settled flat as soon as mounted.I did buy some "Super Lube" to apply after installed. Can recommend these.My rail arrived timely and well protected but the rail itself is bowed up in the middle. I'm sure it'll be fine bolted to an aluminum extrusion but in my application the rail is unsupported and therefor, the rise in the middle is quite apparent when doing a bed mesh measurement. I thought it was an error but I put a straight edge against my glass bed which was straight and smooth. When i put the same straight edge against the linear rail, the variation i found matched the mesh measurement exactly.Perfect little long for my 3d printer but good product my error but still workedWorks great