On 05.05.14 04:48, Gene Heskett wrote: > This one is currently only bolted to its work surface via its front feet, a > 3/4" thick slab of formica covered MDF, which in turn is sitting inside the > "don't let a tool roll off" lip around the edge of heavy duty tool box, on > casters, and sitting on a floor with a noticeable sway, low in the center > of a 12x16 shed.
Gene, it can easily be bed twist. Some years ago, all I did to install my Taiwanese 3/4 ton lathe was adjust the tailstock to cut parallel. (I _assumed_ that the massive bed casting wouldn't twist, sitting on its metal stands, on a "level" concrete floor.) But putting a cheap laser level across the shears, pointing at a wall about 16 feet away, there seemed to be about 0.4mm (10 thou) twist between over the 40" bed length. An inexpensive Chinese machine level, with one division = 0.02mm/m, soon made the hair on the back of my neck stand on end. (Instead of putting it across the shears, as in the books, I laid it on the flat top of the cross-slide, and wound the saddle back and forth. Rapid saddle traverse necessitated quite a few seconds wait for the bubble to settle down.) Just by carefully adjusting one jacking screw at each end, i.e. turning a few tens of degrees, I now have the bed ends parallel, with a bit of twist in the middle, amounting to 5 scale divisions (0.1 mm in 1 m = 0.013 mm across the 133 mm bed). That's a third of thou in the old money, and it'll do me. Of course, I had to put the tailstock back after that, to undo the kludge. I think the machine level was about A$180, so it's worth trying to borrow one, since it's only used for about ten minutes. Erik -- A man with one watch knows what time it is. A man with two watches is never quite sure. ------------------------------------------------------------------------------ Is your legacy SCM system holding you back? Join Perforce May 7 to find out: • 3 signs your SCM is hindering your productivity • Requirements for releasing software faster • Expert tips and advice for migrating your SCM now http://p.sf.net/sfu/perforce _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
