Re: Help WHAT THE HELL IS A FLOATING NUT

Thank´s dude, that actualy made sense!!

San

--- In CAD_CAM_EDM_DRO@y..., "ballendo" <ballendo@y...> wrote:
> San,
>
> Start with a typical old-fashioned square nut (as opposed to the
more
> common hex). Find some material EXACTLY the same thickness as this
> nut, but larger size overall. Put a rectangular hole in this
> material, such that the rectangle is the same size as the nut one
> dir, and bigger the other. Now make two "cover plates" with a
round
> hole a bit bigger than the leadscrew diameter. Time to assemble:
>
> Rub the nut on some emery paper to VERY slightly reduce its
thickness.
> Put one of the covers on the rectangle-hole piece, with its
leadscrew
> hole in the middle of the rectangular "pocket" just created by
> asssembling these two parts. Place the nut in this rectangular
> recess; and close with the other cover plate. Hold the covers on
with
> screws,glue, or whatever makes sense. The rectangular-holed part
> mounts to your machine axis.
>
> Can you see that the nut will be free to move one direction
(because
> of the rectangular recess it is in)? But also that it cannot move
> axially along the screw(except for that little bit you sanded off
to
> make sure it was free "floating" in the rectangular recess)? AND,
> that the nut cannot turn, because the rectangular hole is the same
> size as the nut in one direction? This is a floating nut.
>
> To have it float in two directions will mean the introduction of
some
> backlash, as the nut "turns" in the recess until it hits a "wall"
of
> the recess provided to keep it from turning. And there will be the
> backlash already mentioned from the requirement that the nut be
> thinner than the pocket it sits in...
>
> In short, this is one answer for a low-cost machine when there is
an
> expectation that the ends of the leadscrew will not be accurately
> mounted in relation to the machine axis and/or structure. It also
> allows for the generally poor concentricity of movement of hardware
> store threaded rod...
>
> However, it exchanges one set of problems for the others mentioned.
> This is not in itself a bad thing; ALL cnc machines are compromises
> in some ways. But for a higher quality machine, I would choose a
> different technique; a different set of choices...
>
> Hope this helps,
>
> Ballendo
>
>
> > --- In CAD_CAM_EDM_DRO@y..., "santorelli333" <san3@s...> wrote:
> > > In other words, does anybody have a simple
> illustration/explanation
> > > of the woorking priciple
> > >
> > > San