300mm Ball Screw SFU1204 RM1204 with Nut (End Processing) Precision Part for CNC Machine

I purchased these to upgrade a CNC wood router. The build quality is excellent and the accuracy is well above the simple plastic nut lead screws I am replacing. The only concern is that one needs to provide a suitable bellowed covering to prevent dust from getting into the ball screws. I plan to use thin plastic poly wrap tubing and 3d printed parts to achieve this.

This item was of a very poor quality. It worked fine while going up and down for several turns, and then it got stuck and couldn't move dow anymore. With a little bit of hand-force, it started moving down, but ball bearings started to pop-out through the bottom. So glad I didn't install it yet. It would be a hassle to reassembly my router lift all over again.

I am giving my review 3 starts because the nut fit very well and didn't feel all crudded up before I cleaned the screw. I ended up returning the screws because the upper end shafts were over spec: both measure around 8.012mm at 22c. I froze the screws to -20c and the upper end shrunk to 8.002mm. Still over spec. These screws don't need an interference fit. The lower shaft on one screw was ground properly (9.991mm at room temp) so I could get a set of angular contact bearing on but the second screw was over sized at 10.007mm. I could have froze that screw and got some bearings on but there's no need for that sort of hijinks. No need to press a bearing or freeze a shaft for a ball screw. A location fit should be good enough. Sorry, long rant. 3 starts for nice screw/nut combo; however, the machined ends might not work for you as they didn't for me.

Win some lose some. Ordered 3 lengths, other two were ok but this one was rotten. Couldn't tell until it was in use. Relatively smooth with no crunchy crunchy but backlash was atrocious. .0035 inches. The other two assemblies i was getting less than .0005. No room to install a second nut to adjust for backlash. Bummer. Retrofitting a small bench mill to CNC. The lead screw with jamb nut that cme with it was almost as good as this thing. I guess the old saying is still true, you get what you pay for, Good luck

While I get that with linear rails you should always clean in iso alcohol and then re lubricate, I don't feel the same for ball screws, maybe I should but when I buy more expensive screws they come properly lubed and without needing to be cleaned at all, plus I have never had any of them sound like they have sand in them. The preload on these is pretty high I think which is fine once you are aware of it and the sand sound went away after running the nut up and down the threads a few times. Still these will never just be able to be free spun to move up and down due to the preload. My other screws I can give the nut a good spin and it will keep going a good way up or down the threads. Nothing wrong with these aside from the noise but like I said run the nut back and forth a few times and it runs smoothly enough still better than lead screws any day. The price is decent enough and from first looks I don't see any appreciable run out, will check once I get everything mounted up and update if it's an issue

Excelente producto

Material muy recistente y una buena precisión buen acabado