RE: [CAD_CAM_EDM_DRO] Bent Nook ballscrews ?????

On Mon, 2003-08-11 at 10:18, Carlos Guillermo wrote:

> Hi Kim -
>
> Can you measure the bend?

I'll try later today. It is a bit difficult because you have to measure
to the crest of the thread.

> What kinds of numbers are you seeing?

I'd say 1/16" on a 4 foot screw.

> Or, are you assuming they're bent because the ballnuts are
> jamming?

No, this was something we saw long before we ran nuts on them.

> I ask this because I've heard that the pitch variation on
> rolled ballscrews can be enough to cause jamming if there is no
> compliance element between the two nuts.

The spec on the error of this screw is 0.004" per foot. Our ballnuts
are mounted about 3" apart on the axis in question, so we could see
0.001 or so. I don't think that is enough to jam things.


--
Kim Lux <lux@...>