Re: Need ballscrew support Bearings.

> I got just the bare ballscrew/nut in original factory package on
> eBay last year for under $60. Made in China for Bridgeport. It
> was definitely NOS, over 20 years old, but still in great shape.
> Now, I just need to find an X screw like that!

The BOSS machines used high precision ballscrews made in
Japan by NSK.
This was confirmed by my conversation with a gentleman at
Hardinge who is the BP parts expert and worked for BP for 30
years before they closed.

> >
> > Can I use the lower contact angle (35 degrees) angular contact
> > bearings? Or will they not be able to handle the loads.
> >
> These should be fine, I think. Even ordinary radial bearings
> can take a lot of axial load, the A.C. should be able to handle
> thousands of Lbs even in the 35 deg type.
> > What if they are not a matched pair?
> Unless you intend to just squeeze a pair together with no
> spacers or preload clamping system, you don't need to pay for a
> matched pair. You can use belleville springs or a plate that
> flexes a little under load to apply the preload.

Well Jon, I am not looking to make any alterations to the setup
to get a preload. I was thinking about just using regular
angular contact bearings and using a surface grinder to grind
a little off of the inner race to get my preload. I am not sure
how much I need. The Fafnir original replacement bearings are
available in light, medium and heavy preloads.

> These are mighty big bearings. That 80 mm bearing is going to
> cost at least $60 maybe more, as things seem to have gone up a
> lot lately. Call your local bearing house, they can look up
> practically anything and get you a decent price.

Well $120 for a pair is a lot better than the $680 I was quoted
for a "matched" pair. I am going to have to try this route as I
can not justify spending the money on a matched set.

Thanks,
Scott