Re: Sherline Z-axis ballscrew feed.

Ballendo:

The saddle locking lever does not come as part of Sherline's CNC
ready mill or lathe. This must be purchased seperately, or one has
the option of coming up with their own solution.

Tony


--- In CAD_CAM_EDM_DRO@yahoogroups.com, "ballendo" <ballendo@y...>
wrote:

> Dan,
>
> I agree that your idea has merit. I also agree with TimG that this

is

> all overkill.
>
> Is this the new style nut with the little lever for locking? Thge

one

> that Joe M says to remove or fix in the "off" position?
>
> Because that little lever is key to your solution. I made a little
> piece of brass which held it in a semi-closed position, which
> minimised the backlash...
>
> Hope this helps,
>
> Ballendo
>
> P.S. If you've got the old, non- lockable style z axis nut: The
> sherline thread is 3/8-20, a common thread. Making a decent nut

seems

> a whole lot less work, IMO. You may even be able to add your own
> version of a "starwheel", like Sherline uses on the xand y...
>
> Here's how: Start with a brass nut threaded for the leadscrew. Turn
> its OD to fit, and mill or file grooves for the "star" shape. tap a

4-

> 40 or so hole in the flat back of the existing nut. Using a piece

of

> springy sheet, or music wire held by a 4-40 screw in this hole,

bend

> til it engages the grooves in your star nut, which is screwed into
> position above the existing nut (like the new style locking lever).
> Viola, A/b nut.
>
>
>
>
> --- In CAD_CAM_EDM_DRO@yahoogroups.com, "Statman Designs, LLC"
> <titanium@c...> wrote:
> > I have a question for the group of experts here.
> >
> > How difficult would it be to create a Z-axis for the Sherline
> milling
> > machines that used a zero-backlash ballscrew drive mechanism? I

am

> not
> > suggesting that you retro-fit a ball-screw to an existing Z-

axis.

> The
> > Z-axis simply bolts to the X-Y table and the spindle and motor
> assembly
> > simply bolt to the Z-axis.
> >
> > How difficult would it be to completely replace the Z-axis with a
> ballscrew
> > assembly and then re-mount the Sherline motor and spindle to the
> new Z-axis?
> >
> > It seems that this would be quite a worth while upgrade for the
> Sherline CNC
> > system. The Z-axis is the weakest link in the ability to do
> repeatable work
> > on the Sherline. There is no backlash adjustment mechanism and

the

> spindle
> > and motor do not weigh enough to always stay at the bottom of the
> leadscrew
> > pitch. This can, and has, resulted in large jumps of the Z-axis
> downward as
> > it settles to the bottom of the screw pitch.
> >
> > Daniel J. Statman, Statman Designs
> > www.statmandesigns.com
> > dan.statman@r...