Re: Ball screw accuracy

> Ron Brown wrote:
>
> > All,
> >
> > I tried to navigate the hiwin website. But, with a telephone company that has the maximum capacity of 19,200 BPS, I sent an e-mail instead.
> >
> > 'Sal' with sales stated there were two ballscrews available. One with .003" accuracy per foot; the other with ground threads and .0005" accuracy per foot. Prices are $650 and $950.
> >
> > Are ballscrews suitable for 'hand' operation. I have been told ballscrews allow too much feedback and are not suitable for manual operation.
>

Ron,

I used the Hiwin 25mm ballscrews on my gantry router. I was a little skeptical of the quality but
after visiting their Chicago warehouse I found they were very good and about half the price
of anyone else. Mine are .003"/ft and oversize ball preloaded to 5% max dynamic load. Preload
drag is very smooth and low. I still have one on back order.

You will have to deal with the end machining though. I have no problems using c6 carbide to
cut through the RC 55-58 case. The core is about RC 40 and can be easily cut. Often one end
of the screw will be annealed and even easier to cut- they are shipped as one long piece with
two nuts that is cut to make two assemblies. Only the outer ends are soft.

I just got a Themac tool post grinder that should make the job even easier for me. Tenths matter
on the diameter and the last .0005" or so should be ground or honed to size.

Leslie M.Watts
Illinois Tool Works
Corporate Advanced Technology group
(847) 657-4559
http://www.netcom.com/~leswatts/leswp.html