VEVOR Juego de guías de carril lineal, 2 piezas, 20 mm x 1000 mm, juego de guías de rodamiento lineal con 4 rodamientos de bloque SC20UU+4 piezas de soporte de eje, kits de piezas CNC de eje lineal para barra guía de equipos electrónicos

I recently bought a stereo microscope head and needed a stand for it. The best stands are double arm boom stands, which use two linear rails. I have a 3D printer, so I figured, why not just build one? Looking at McMaster-Carr, linear rails and pillow blocks are EXPENSIVE. I looked elsewhere online, and they still weren't anywhere near what I wanted to pay. So then, of course, I checked Amazon and found these. I probably could have gotten away with the 16mm rails for my application, but I decided on the 20mm x 1m. First of all, they're super heavy. I guess that should be expected. They have a nice coating of oil on them, which seems to get on everything like anti-seize does - nothing a little brake cleaner can't take care of. The rails are straight and have a nice polish, and they measure 20mm +0.1/-0.2. The ends aren't chamfered, which would have been preferable, but that's an easy fix. The pillow blocks seem well made, with recirculating ball type bearings in them. Putting the two together, the blocks slide nicely on the rails, though they're a bit loud. The dust seals on the blocks seem to be well-fitted and there's no discernible play in the bearings. I need to cut these rails down, and I did so using an angle grinder with a cutoff wheel. I then polished and chamfered the ends with a 120 grit flap disc. Cutting took a couple of minutes per cut. You could probably do it with a hacksaw but it'll take you all afternoon. Out of curiosity, I tried drilling into a piece of the rail and I was able to drill without too much problem, so the rails aren't too terribly hard. Overall, these are a great choice if you need a set of linear rails, pillow blocks, and mounting blocks. I'll be posting my build to Hackaday and thingivese, and I'll be recommending these rails to anyone looking to build their own microscope stand.

These rails work just fine for low precision applications and slide fairly nice.

The rails are wonderful and work as described. Quality piece. Would have been nice if screws were available as I had to go to hardware store and purchase screws. Also, I would have liked is if the Router Plate was made available, a plate with drilled out holes that match up with the rail slides. If I missed something, please respond back with a part number for the plate....if none available then I will have to make one.......would prefer one that is already made with perfectly aligned screw holes already made. Other than that, good quality and quick shipping...

Build a circular saw crosscut sled with these. They glide smooth, don’t rack, and somehow the sawdust doesn’t affect them (yet? But if so in the future it’s likely my fault and I’ll need to clean and grease). The picture is from the work in progress building, but my review is based on my experience after building a couple cabinets and using them for a bit.

The rods are solid and quite heavy. The blocks move very smoothly with no discernible play. I made a router sled with 2 pairs of these. My only concern is that there was a little bit of sideways twisting when the router was near the end of the rods. It did not really affect the router's perfotmace.

Smooth and well put together.

The flex on theseMake making no good to build a router sled with them I know it's not what they were meant for but they at least should not have had as much bow in it as it did for the kind of steel it is. Definitely will be purchasing the one that has the underlay in it to help keep it more stern and sturdy.

Made a router sled with one pair of these , another pair of the ones with a base, and three pieces of acrylic. Works great. Strong rigid rail rods. Surpringly good value.

This unit came As advertised. Cant wait to use it check it’s tolerance and smooth working .the standard measurement of the slide bearing set needs to better advertised due to the other units are not capable of being used on longer units from the same company.

Works perfectly! Saved a lot of money! I couldn't have built a better router sled. I would definitely recommend.