Re: rolled ball screws

Ballendo, could you tell us some sources to
get the oversized balls from?
Also curious about the size range that you ended
up with, assuming you had several sizes to play with.
Thanks


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

> Hoyt,
>
> Different strokes for different folks...
>
> A coupla differences between my recomendations and your response:
>
> 1)Using two nuts costs more out of pocket, plain and simple. This
> group is aimed at DIY so the "asm'g" is not that big of deal.
> Especially compared to machining the parts to join two nuts! (which
> is easier, pouring out some balls and putting new ones in? Or

buying

> TWO nuts; engineering, buying and making the parts to allow for
> preload, and assembling too? Which point you prob'ly will have to

re-

> load some balls anyway!)
>
> 2) the length OF two nuts, PLUS the distance BETWEEN the two nuts,
> means that any lead variation will be increased in its effect,
> compared to the one nut approach. Which "leads"(pun intended) to

the

> fact that the yield issue, which you have correctly stated exists

in

> BOTH cases, is much less for the single nut technique I outlined.
>
> Both Dan Mauch and myself (at least) have done this successfully. I
> have also made double nut preloads. I can say that for me, the

single

> nut is MUCH easier.
>
> Hope this helps,
>
> Ballendo
>
>
> --- In CAD_CAM_EDM_DRO@yahoogroups.com, Hoyt McKagen <bjammin@i...>
> wrote:
> > At 04:04 PM 1/27/03 -0000, you wrote:
> > >The bottom-er line is that if you have a non-compliant spacer
> between
> > >two nuts on a rolled ballscrew, you will then USE the yield

value

> of
> > >the bearings and races themselves to accomodate the inherent

lead

> > >innaccuracies.
> >
> > Too harsh. There's always a certain amount of elastic distortion

in

> any
> > material.
> >
> > >What CAN work with rolled thread, is to slightly oversize the
> balls.
> >
> > This amounts to exactly the same thing. In either cae you're
> relying on
> > elasticity.
> > But putting a spacer into the system is easier than asm,g

oversize

> balls.
> >
> >
> > Regards, Hoyt McKagen
> >
> >
> > Anti-virus request: Please do not add this email addy to address
> books
> > Belfab CNC - http://www.freeyellow.com/members/belfab/belfab.html
> > US Best MC -

http://www.freeyellow.com/members/batwings/best.html

> > Camping/Caving -
> http://www.freeyellow.com/members/batwings/caving.html
> > The stones of the pyramids were poured, not cut