Re: spinning ball nuts

--- In CAD_CAM_EDM_DRO@yahoogroups.com, Jon Elson <elson@p...> wrote:

>
>
> plastiguy wrote:
>

> >an unrealistically large diameter lead screw solution (financially
> >unrealistic, that is). So, instead of putting in a 1.5" diameter
> >screw and spinning the screw, I'm considering a smaller dia.
> >stationary screw and then spinning the nut (can go as fast as I want
> >then).
> >

> they have a barrel that is supended between tapered roller bearings.
> The nut mounts inside the barrel, and a toothed pulley mounts on the
> end, outside the bearings. The nut mount has to be done so the screw
> doesn't wobble around in a circle as the barrel and nut turn.
>
> Jon

There is sign shop here that uses a gantry machine with an eight ft
cutting cap. I think the screw is nine ft long and 3/4 in dia. It's
run down the center and fixed, spinning the nut. It's 2 turns per in.
As Jon said about wobble this machine uses antibacklash nuts. So no
wobble. Rapids are 600 in per min. On my machine I'm spinning a 3/4
screw, 5 turns per in , nuts fixed, and had problems with wobble, do
to side slack using standard nuts. My cheap fix was to make a sloted
collar that I fitted to the nuts, which part of rested against the
screw.

If I get a chance this week i'll take some picts and the name of this
machine.

Frank