CNBTR Horizontal 8mm Dia Linear Motion Ball Bearing Slide Bushing &200mm Linear Shaft Optical Axis with Rod Rail Support Set

These are great for multiple applications, my personal purpose of buying this particular size is to increase the thickness of material that I can use on a 3018 cnc router, as they are absolutely perfect for personal cnc modification, I do have a couple complaints however, my main complaint is the staples used to seal the packaging, they are sharp and poorly secured, I got cut while reaching into the box with various other items.My other complaint is that there are no screws for the pillows which forces the buyer to further invest.One of the pillows are missing most of it's bearings, had I not ordered two setsto have backup parts I would have been highly dissatisfied. However these are of decent quality of and are perfect for infinite small projects. You really won't find anything this size in better quality and if you are adding an axis or modifying a pre-existing axis these are definitely what you are looking for. I suggest buying two sets to be safe especially if you are going to be using them for a spindle as vibration will eventually render them unstable as with any bearings. Will buy again if/when necessary. Also they arrived in like three days with standard shipping!

This was exactly what I was looking for and it fits nicely into my project.

Bearings do have some play and grittiness to them but have worked well in a cnc application.

Good product for a relatively cheap price. Takes metric screws (M4, pitch=.7). The metal is a little soft for the brackets, but they do the job.

nice product

The linear bearings are relatively loose and very gritty... They seem to roll well if you rotate the shaft, but har horibble for linear motion... But, that said, you get what you pay for :) I guess I hoped for more, but for my application it will work okay. I many see if a little grease will help... What did I expect?--- a similar product for McMasterCarr would have been 10 times the price... So, I guess I can't complain... In a nutshell, they will work for my application, but I don't need super precision...

Poor quality control. 1 of the 4 bearings slides effortlessly, but the rest stick to the rails, requiring several ounces of pressure to even move. Mind you, I bought 2 sets of these, and of the 8, only 2 move like I would expect them to.Drill holes in mounting brackets also are not uniform. Up to 1mm off.

Bearings stick and freeze up on railing and set screws in rail post are impossible to turn with out stripping out. Applied oil to bearings with no improvement.