Steve Blackmore wrote: > On Sat, 16 Feb 2013 13:34:52 +0000, you wrote: > > >> Has anyone tried reducing the backlash in a ballnut by fitting oversized >> balls? >> If so, how did it turn out? >> > > Andy - commercially they don't replace every ball with oversize ones. > Some do, some don't.
> They replace every "n" th ball with a slightly oversize one. If the rebuilder uses two different sizes then the smaller ones alternate with the larger, that way the smaller counter rotate to keep down friction. The load capacity decreases. Any other ratio defeats the purpose. > It's a bit > of a black art and the guys sort of do it by feel. Feel is the key, that and having a varied selection of sizes to try. > I've seen a screw > that was rebuilt by some company in the midlands and it was superb, and > much cheaper than a replacement, but still out of my pocket. > > I did have a go doing all the linear slides on an Isel router, I > replaced every 5th ball with oversize ones and replaced all the other > balls with correctly sized ones and it worked great. Only having 1 of 5 oversize either loses rigidity with the correct size or greatly increases the strain on the individual balls and the contact points of the slide if you go oversize and go by feel > That had had a hard > life cutting ceramic and the dust had got in despite the fact the ways > are covered and the inside was air pressurized in an attempt to keep the > dust out. > > Steve Blackmore > -- > Ed. ------------------------------------------------------------------------------ The Go Parallel Website, sponsored by Intel - in partnership with Geeknet, is your hub for all things parallel software development, from weekly thought leadership blogs to news, videos, case studies, tutorials, tech docs, whitepapers, evaluation guides, and opinion stories. Check out the most recent posts - join the conversation now. http://goparallel.sourceforge.net/ _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
