Re:Lead screws

Check in the files section.

Les posted a method of using a level to get straight ways. since
this is all hand work, the completed size is not a problem, 10 feet
or 100 feet, it just takes time.

Ditto for screws. once you have one inch of perfect screw, you can
cut one inch for a die, then cut a looooooong screw. then figure the
error in the screw and make that up with gearing. Then with your new
looooon bed and your new looooog screw you can machine lots and lots
more.

I can't think of how to get this on topic, so I'll considder this
thread ending quickly.

Dave

--- In CAD_CAM_EDM_DRO@yahoogroups.com, Don Rogers <Don@C...> wrote:
> At 12:18 AM 5/15/03 +0000, you wrote:
> >It comes in different levels of linear precision and it is fairly
inexpensive.
>
> And
>
> >Ball screws are quite expensive but offer less turning resistance
and more
> >accuracy than acme rod
>
> This brings up a "which came first, the chicken or the egg"
question.
>
> Some 40 years back, while I was an apprentice machine repairman, I
> marveled at the huge machines that I worked on whose purpose was to
make
> smaller machines. The question came up in my mind, how can you
machine a
> 40 ft bed on a planer when the biggest machine you have is a 30 ft
machine,
> an to boot, to get a 40 ft bed, you need at least 80 ft of travel?
If you
> have a large machine, you can make a smaller one, but how do you
make a
> bigger one?
>
> Now, we are talking about lead screw accuracy, how do we get 0.001"
per
> foot accuracy when the best lead screw we have is 0.006" per foot?
And how
> did we come up with one that accurate when a machine that accurate
didn't
> exist yet?
>
> With that, nite nite
>
> Don
>
>
>
>
>
>
> [Non-text portions of this message have been removed]