review of chinese rails and bearing blocks from Econvience

I purchased 4 1500mm x30mm rails and 8 x 30mm bearing blocks from econvience about 2 weeks ago.Shipping was pretty resonable considering the length and weight of the rails.The rails arrived first about a week from sending payment and were well packed.They were wrapped in bubble rap and tarp material and some form of hemp rope wrapped around them to hold them together then tapped.The shafts of the rails were facing inwards to avoid damage to them.I examined them closely and found only minor damage to the very ends of the supports which I could fix with a crescent wrench (slight bends) and some light filling.What I found strange was every other bolt that holds the rails to the supports was stripped and or bent.Luckily the threads in the rails was fine although I did run a 6mm tap to clean them up abit. I noticed the threads are recessed very deep into the rails ,so deep that the 6mmx25mm cap screws only get a few threads on them before getting tight.The only reason I could see for doing that is to get away from the hardened outside of the shaft to make tapping easier but I ordered some 30mm long screws to use after i get everthing mocked up and ready for final install.I checked them for straightness and roundness and mesurments were consistent . One thing I noticed right away is the lack of deburring on both the supports where the rails sit and where the supports mount on your frame and where the rails are drilled and tapped. I deburred both parts and the rails sit true in the supports.They came wiped with oil to keep them from rusting.The day after I got the rails the bearing blocks arrived and I took them all out and inspected them.They all ran well on the rails and even better as weight was applied.The
bolt holes were all consistent and allowed me to make a pattern to speed up laying them out.The bearings run in an oval like track and the way they fit in the track they can't fall out like some people mentioned on youtube.The bearings are oiled and the blocks have preload set screws but no where to grease the bearings.I would love to know what some of you use to lube your bearing with.So far i've mounted two rails for the y axis and used 4 blocks for my gantry uprights and had to retap one bearing block. I installed all the 8mm bolts by hand except the one which would
only let me get down half way or so before tightening up,I suspect they don't know what a bottom tap is for. I expect to do more retapping as the project moves foward.The conclusion is expect to do some tapping and replace some bolts and deburring.I had good communication from Leo from getting the order together and sorting out the problems with the screws in the rails.I have not heard back from him as it's the weekend but he will resolve the problem.I'm using 6mm x 30mm screws to mount the rails to the machine frame so I can use the same screws to secure the rails to the supports.If you have any questions just ask.AJ