Re: Screw drive

I just looked at the sketch amasing concept.
I assume the 3 short screws will be freewheeling
around the outer circumference.
Seams like it would work but I think any contaminent
encountered between the rolling surfaces would cause
them to stop turning and starting to ware out quickly.
Also the 3 point contact area around the circumference
will lead to some low loadbearing.
The 3 short screws would have to be held to some tight
tolerances axialy to reduce backlash.
I would like to hear more about this, anybody that has
build and used this in a practical application?

--- In CAD_CAM_EDM_DRO@yahoogroups.com, "alex" <telecomt@t...> wrote:
> OK,
> just loaded the scetch into file section.
> Called screwdrive .jpg.
> Let me know if you have questions.
> Regards, Alex
> ----- Original Message -----
> From: Dantrol <dantrol@o...>
> To: <CAD_CAM_EDM_DRO@yahoogroups.com>
> Sent: Friday, March 28, 2003 8:46 AM
> Subject: [CAD_CAM_EDM_DRO] Re: Screw drive
>
>
> > Alex, I do not have easy access to the magazine. Is it possible
for you to
> better describe, or sketch, the "make-your-own" screw drive? Thanks.
> >
> > 3-27-03, alex, telecomt@t..., Screw drive
> > Yesterday I stumbled upon "Model Engineer's Workshop" magazine.
Besides
> other interesting staff there was an article on making your own
> > screw drive as a replacement for a ball screw. I'm amazed at how
easy and
> inexpensive is to make this kind of drive - basically its an
arrangement of
> three short screws, belonging to a nut, around the drive screw. One
short
> screw can be tightened to adjust the backlash. It looks like anyone
can make
> this kind of drive in a matter of hours. Cheap too.
> >
> >
> >
> > [Non-text portions of this message have been removed]
> >
> >
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