Re: [CAD_CAM_EDM_DRO] Re: greetings

In a message dated 18-Sep-00 00:30:26 Central Daylight Time,
dandowell@... writes:

<< Here I go again. Whats a preload nut? Would like to see one. >>

Dan: A plain-ol' "hex-nut" "wiggles" a bit on the bolt, as you thread it on,
right? OK, suppose you put on TWO nuts, and run them against each other
"just snug" until they still turn, but "snugly". Then, no or not-much
"wiggle", right? That is "pre-load". In a precision ball-screw, there is
"back-lash", where, if the screw is moving a nut along, and you stop, and
reverse rotation, the nut "stays put" for a few thousandths, before it, too,
reverses (linear) direction. BUT, if you put TWO ball-nuts on that screw,
and have a thin spring between 'em, and run them "up against the spring" so
that they still turn, but are "pre-loaded" against each other, then, when you
reverse direction of rotation of the screw, the "double-nut combination" will
reverse with NO "backlash", due to this "preload". Got that? Expensive.
Precision. Harder to set-up than car-jacks. Maybe even dangerous in some
situations. A sit-down in a saloon with a bottle of J.D. in front of you is
far more attractive! Wot???

Did that answer the question? Poorly, but "Just"???