2PCS Linear Rails SBR12 300mm Linear Guide Rails with 4PCS SBR12UU Slide Blocks, CNC Rail Kit, Linear Rails and Bearings Kit for Automated Machines and Equipments(SBR12-300)

Surprisingly durable Thomson rod equivalent for a very good value. High quality stuff, with only one exceptionally minor complaint. Upon receiving the rails, I tested the bearings, and one of them drags a bit, and does not move as freely as the others. However, I cleaned the bearing and re-lubricated it, and now the issue has ceased, so it was very likely the result of dried lubricant.

Work's great, not real easy to install but worth it

I ordered this hoping to be able to use it for a new product. What I found out that it has sloop from side to side. It could never be used for anything that requires registration from side to side. The plate on top would have to be aligned to something by bars that went to a slot or groove on both sides to make sure that it was registered for a right angle. From what I can see it does rotate about the z axis from side to side (if you are looking down the track as a front view) by about 5 to 10 degrees at least. It does side easy enough but not good for accuracy. If they had made something that registered it to the track so that the plate is parallel to the track then I would use something like this. It would have been very easy to do, but they did not. I can recommend this for anything that needs registration.

These have been in use for almost a year. No issues rock solid tolerance

I ordered some smaller lengths, but they sent me a much larger rail. I decided to cut them with a cutoff grinder since they are hardened. this went ok. overall quality is good for the money. the slides are a little loose but they do have some set screws to adjust this. i don't hink they will hold up to continious everyday use, but for my CNC router Z axis they are fine. Would buy again.

Its what I need but the bearings started falling out as soon as I u packaged it

I used this product to make a portable drill press. These linear rails and slide blocks a very accurate and work smooth.

envio rapido el unico inconveniente es que los rieles estan un poco torcidos debido a un mal ajuste de los tornillos que se encuentran en la parte de abajo de los rieles pero en mi caso no necesito tanta precision por lo que me sirven sin embargo en el control de calidad del fabricante deberian ser mas detallistas ya que de esto depende su desempeño